The Navigable Waters Protection Rule: Definition of “Waters of the United States”

CourtArmy, Corps Of Engineers Department
Citation85 FR 22250
Record Number2020-02500
Publication Date21 April 2020
Federal Register, Volume 85 Issue 77 (Tuesday, April 21, 2020)
[Federal Register Volume 85, Number 77 (Tuesday, April 21, 2020)]
                [Rules and Regulations]
                [Pages 22250-22342]
                From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
                [FR Doc No: 2020-02500]
                [[Page 22249]]
                Vol. 85
                Tuesday,
                No. 77
                April 21, 2020
                Part II
                Department of Defense
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                Department of the Army, Corps of Engineers
                Environmental Protection Agency
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                33 CFR Part 328
                40 CFR Parts 110, 112, 116, et al.
                The Navigable Waters Protection Rule: Definition of ``Waters of the
                United States''; Final Rule
                Federal Register / Vol. 85, No. 77 / Tuesday, April 21, 2020 / Rules
                and Regulations
                [[Page 22250]]
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                DEPARTMENT OF DEFENSE
                Department of the Army, Corps of Engineers
                33 CFR Part 328
                ENVIRONMENTAL PROTECTION AGENCY
                40 CFR Parts 110, 112, 116, 117, 120, 122, 230, 232, 300, 302, and
                401
                [EPA-HQ-OW-2018-0149; FRL-10004-88-OW]
                RIN 2040-AF75
                The Navigable Waters Protection Rule: Definition of ``Waters of
                the United States''
                AGENCY: Department of the Army, Corps of Engineers, Department of
                Defense; and Environmental Protection Agency (EPA).
                ACTION: Final rule.
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                SUMMARY: The Environmental Protection Agency and the Department of the
                Army are publishing a final rule defining the scope of waters federally
                regulated under the Clean Water Act. The Navigable Waters Protection
                Rule is the second step in a comprehensive, two-step process intended
                to review and revise the definition of ``waters of the United States''
                consistent with the Executive Order signed on February 28, 2017,
                ``Restoring the Rule of Law, Federalism, and Economic Growth by
                Reviewing the `Waters of the United States' Rule.'' Once effective, it
                replaces the rule published on October 22, 2019. This final rule
                implements the overall objective of the Clean Water Act to restore and
                maintain the integrity of the nation's waters by maintaining federal
                authority over those waters that Congress determined should be
                regulated by the Federal government under its Commerce Clause powers,
                while adhering to Congress' policy directive to preserve States'
                primary authority over land and water resources. This final definition
                increases the predictability and consistency of Clean Water Act
                programs by clarifying the scope of ``waters of the United States''
                federally regulated under the Act.
                DATES: This rule is effective on June 22, 2020.
                ADDRESSES: The EPA has established a docket for this action under
                Docket ID No. EPA-HQ-OW-2018-0149. All documents in the docket are
                listed on the http://www.regulations.gov website. Although listed in
                the index, some information is not publicly available, e.g., CBI or
                other information whose disclosure is restricted by statute. Certain
                other material, such as copyrighted material, is not placed on the
                internet and will be publicly available only in hard copy form.
                Publicly available docket materials are available electronically
                through http://www.regulations.gov.
                FOR FURTHER INFORMATION CONTACT: Michael McDavit, Oceans, Wetlands, and
                Communities Division, Office of Water (4504-T), Environmental
                Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460;
                telephone number: (202) 566-2465; email address: [email protected]; or
                Jennifer A. Moyer, Regulatory Community of Practice (CECW-CO-R), U.S.
                Army Corps of Engineers, 441 G Street NW, Washington, DC 20314;
                telephone number: (202) 761-5903; email address:
                [email protected].
                SUPPLEMENTARY INFORMATION:
                Table of Contents
                I. General Information
                 A. Where can I find information related to this rulemaking?
                 B. What action are the agencies taking?
                 C. What is the agencies' authority for taking this action?
                II. Background
                 A. The Final Rule
                 B. History of This Rulemaking
                 1. The Clean Water Act
                 2. Regulatory History
                 3. U.S. Supreme Court Decisions
                 4. The 2015 Rule
                 C. Executive Order 13778 and the ``Step One'' Rulemaking
                 D. Summary of Stakeholder Outreach and the ``Step Two''
                Rulemaking
                 E. Overview of Legal Construct for the Final Rule
                 1. Statutory Framework
                 2. U.S. Supreme Court Precedent
                 3. Principles and Considerations
                 F. Summary of Final Rule as Compared to the 1986 Regulations
                Recodified in the 2019 Rule and the 2015 Rule
                 G. Existing Guidance
                III. Definition of ``Waters of the United States''
                 A. Key Terms and Concepts
                 1. Typical Year
                 2. Perennial, Intermittent, and Ephemeral
                 3. Breaks
                 B. Territorial Seas and Traditional Navigable Waters
                 C. Interstate Waters
                 D. Tributaries
                 E. Ditches
                 F. Lakes and Ponds, and Impoundments of Jurisdictional Waters
                 G. Adjacent Wetlands
                 H. Waters and Features That Are Not Waters of the United States
                 I. Placement of the Definition of ``Waters of the United
                States'' in the Code of Federal Regulations
                IV. State, Tribal, and Federal Agency Datasets of Waters of the
                United States
                V. Overview of the Effects of the Rule and Supporting Analyses
                VI. Statutory and Executive Order Reviews
                 A. Executive Order 12866: Regulatory Planning and Review;
                Executive Order 13563: Improving Regulation and Regulatory Review
                 B. Executive Order 13771: Reducing Regulation and Controlling
                Regulatory Costs
                 C. Paperwork Reduction Act
                 D. Regulatory Flexibility Act
                 E. Unfunded Mandates Reform Act
                 F. Executive Order 13132: Federalism
                 G. Executive Order 13175: Consultation and Coordination With
                Indian Tribal Governments
                 H. Executive Order 13045: Protection of Children From
                Environmental Health and Safety Risks
                 I. Executive Order 13211: Actions Concerning Regulations That
                Significantly Affect Energy Supply, Distribution, or Use
                 J. National Technology Transfer and Advancement Act
                 K. Executive Order 12898: Federal Actions To Address
                Environmental Justice in Minority Populations and Low-Income
                Populations
                 L. Congressional Review Act
                I. General Information
                A. Where can I find information related to this rulemaking?
                 1. Docket. An official public docket for this action has been
                established under Docket ID No. EPA-HQ-OW-2018-0149. The official
                public docket consists of the documents specifically referenced in this
                action and other information related to this action. The official
                public docket is the collection of materials that is available for
                public viewing at the OW Docket, EPA West, Room 3334, 1301 Constitution
                Ave. NW, Washington, DC 20004. This Docket Facility is open from 8:30
                a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The
                OW Docket telephone number is (202) 566-2426. A reasonable fee will be
                charged for copies.
                 2. Electronic Access. You may access this Federal Register document
                electronically under the ``Federal Register'' listings at http://www.regulations.gov. An electronic version of the public docket is
                available through EPA's electronic public docket and comment system,
                EPA Dockets. You may access EPA Dockets at http://www.regulations.gov
                to view public comments as they are submitted and posted, access the
                index listing of the contents of the official public docket, and access
                those documents in the public docket that are available electronically,
                including the economic and regulatory analyses for the final rule. For
                additional information about
                [[Page 22251]]
                EPA's public docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm. Although not all docket materials may
                be available electronically, you may still access any of the publicly
                available docket materials through the Docket Facility.
                B. What action are the agencies taking?
                 In this notice, the agencies are publishing a final rule defining
                ``waters of the United States'' in 33 CFR 328.3 and 40 CFR 120.2.
                C. What is the agencies' authority for taking this action?
                 The authority for this action is the Federal Water Pollution
                Control Act, 33 U.S.C. 1251 et seq., including sections 301, 304, 311,
                401, 402, 404, and 501.
                II. Background
                A. The Final Rule
                 The U.S. Environmental Protection Agency (EPA) and the U.S.
                Department of the Army (Army or Corps) (together, ``the agencies'') are
                publishing the Navigable Waters Protection Rule defining the scope of
                waters subject to federal regulation under the Clean Water Act (CWA or
                the Act), in light of the U.S. Supreme Court cases in United States v.
                Riverside Bayview Homes (Riverside Bayview), Solid Waste Agency of
                Northern Cook County v. United States (SWANCC), and Rapanos v. United
                States (Rapanos), and consistent with Executive Order 13778, signed on
                February 28, 2017, entitled ``Restoring the Rule of Law, Federalism,
                and Economic Growth by Reviewing the `Waters of the United States'
                Rule.''
                 In this final rule, the agencies interpret the term ``waters of the
                United States'' to encompass: The territorial seas and traditional
                navigable waters; perennial and intermittent tributaries that
                contribute surface water flow to such waters; certain lakes, ponds, and
                impoundments of jurisdictional waters; and wetlands adjacent to other
                jurisdictional waters. Paragraph (a) of the final rule identifies four
                categories of waters that are ``waters of the United States.'' These
                waters are referred to as ``jurisdictional'' in this notice and in the
                regulatory text. Paragraph (b) of the final rule identifies those
                waters and features that are excluded from the definition of ``waters
                of the United States.'' These waters are referred to as ``non-
                jurisdictional'' or ``excluded'' in this notice and as ``non-
                jurisdictional'' in the regulatory text. Paragraph (c) of the final
                rule defines applicable terms.
                 As a baseline concept, this final rule recognizes that waters of
                the United States are waters within the ordinary meaning of the term,
                such as oceans, rivers, streams, lakes, ponds, and wetlands, and that
                not all waters are waters of the United States. The final rule includes
                the agencies' longstanding category of the territorial seas and
                traditional navigable waters. A ``tributary'' is defined in the final
                rule as a river, stream, or similar naturally occurring surface water
                channel that contributes surface water flow to a territorial sea or
                traditional navigable water in a typical year either directly or
                indirectly through other tributaries, jurisdictional lakes, ponds, or
                impoundments, or adjacent wetlands. A tributary must be perennial or
                intermittent in a typical year. The alteration or relocation of a
                tributary does not modify its jurisdictional status as long as it
                continues to be perennial or intermittent and contributes surface water
                flow to a traditional navigable water or territorial sea in a typical
                year. A tributary does not lose its jurisdictional status if it
                contributes surface water flow to a downstream jurisdictional water in
                a typical year through a channelized non-jurisdictional surface water
                feature, through a subterranean river, through a culvert, dam, tunnel,
                or other similar artificial feature, or through a debris pile, boulder
                field, or similar natural feature. The term ``tributary'' includes a
                ditch that either relocates a tributary, is constructed in a tributary,
                or is constructed in an adjacent wetland as long as the ditch is
                perennial or intermittent and contributes surface water flow to a
                traditional navigable water or territorial sea in a typical year.
                 The final rule defines ``lakes and ponds, and impoundments of
                jurisdictional waters'' as standing bodies of open water that
                contribute surface water flow in a typical year to a territorial sea or
                traditional navigable water either directly or through a tributary,
                another jurisdictional lake, pond, or impoundment, or an adjacent
                wetland. The agencies note that to be jurisdictional, an ``impoundment
                of a jurisdictional water'' must be an impoundment of a territorial sea
                or traditional navigable water, tributary, jurisdictional lake or pond,
                or an adjacent wetland, and must meet the conditions in paragraph
                (c)(6) of the final rule. A lake, pond, or impoundment of a
                jurisdictional water does not lose its jurisdictional status if it
                contributes surface water flow to a downstream jurisdictional water in
                a typical year through a channelized non-jurisdictional surface water
                feature, through a culvert, dike, spillway, or similar artificial
                feature, or through a debris pile, boulder field, or similar natural
                feature. A lake, pond, or impoundment of a jurisdictional water is also
                jurisdictional if, in a typical year, it is inundated by flooding from
                a territorial sea or traditional navigable water, or tributary, or from
                another jurisdictional lake, pond, or impoundment.
                 The final rule defines ``adjacent wetlands'' as wetlands that abut
                a territorial sea or traditional navigable water, a tributary, or a
                lake, pond, or impoundment of a jurisdictional water; are inundated by
                flooding from a territorial sea or traditional navigable water, a
                tributary, or a lake, pond, or impoundment of a jurisdictional water in
                a typical year; are physically separated from a territorial sea or
                traditional navigable water, a tributary, or a lake, pond, or
                impoundment of a jurisdictional water only by a natural berm, bank,
                dune, or similar natural feature; or are physically separated from a
                territorial sea or traditional navigable water, a tributary, or a lake,
                pond, or impoundment of a jurisdictional water only by an artificial
                dike, barrier, or similar artificial structure so long as that
                structure allows for a direct hydrological surface connection to the
                territorial sea or traditional navigable water, tributary, or lake,
                pond, or impoundment of a jurisdictional water in a typical year, such
                as through a culvert, flood or tide gate, pump, or similar artificial
                feature. ``Abut'' means when a wetland touches a territorial sea,
                traditional navigable water, tributary, or lake, pond, or impoundment
                of a jurisdictional water at least at one point or side. An adjacent
                wetland is jurisdictional in its entirety when a road or similar
                artificial structure divides the wetland, as long as the structure
                allows for a direct hydrologic surface connection through or over that
                structure in a typical year.
                 The final rule excludes from the definition of ``waters of the
                United States'' all waters or features not mentioned above. In addition
                to this general exclusion, the final rule specifically clarifies that
                waters of the United States do not include the following:
                 Groundwater, including groundwater drained through
                subsurface drainage systems;
                 ephemeral features that flow only in direct response to
                precipitation, including ephemeral streams, swales, gullies, rills, and
                pools;
                 diffuse stormwater runoff and directional sheet flow over
                upland;
                 ditches that are not traditional navigable waters,
                tributaries, or that are
                [[Page 22252]]
                not constructed in adjacent wetlands, subject to certain limitations;
                 prior converted cropland;
                 artificially irrigated areas that would revert to upland
                if artificial irrigation ceases;
                 artificial lakes and ponds that are not jurisdictional
                impoundments and that are constructed or excavated in upland or non-
                jurisdictional waters;
                 water-filled depressions constructed or excavated in
                upland or in non-jurisdictional waters incidental to mining or
                construction activity, and pits excavated in upland or in non-
                jurisdictional waters for the purpose of obtaining fill, sand, or
                gravel;
                 stormwater control features constructed or excavated in
                upland or in non-jurisdictional waters to convey, treat, infiltrate, or
                store stormwater run-off;
                 groundwater recharge, water reuse, and wastewater
                recycling structures constructed or excavated in upland or in non-
                jurisdictional waters; and
                 waste treatment systems.
                 In addition, the agencies have defined the terms ``upland,''
                ``prior converted cropland,'' and ``waste treatment system'' to improve
                regulatory predictability and clarity.
                 To develop this revised definition of ``waters of the United
                States,'' the agencies looked to the text and structure of the CWA, as
                informed by its legislative history and Supreme Court guidance, and
                took into account the agencies' expertise, policy choices, and
                scientific principles. This final rule presents a unifying legal theory
                for federal jurisdiction over those waters and wetlands that maintain a
                sufficient surface water connection to traditional navigable waters or
                the territorial seas. This definition strikes a reasonable and
                appropriate balance between Federal and State waters and carries out
                Congress' overall objective to restore and maintain the integrity of
                the nation's waters in a manner that preserves the traditional
                sovereignty of States over their own land and water resources. The
                final rule also provides clarity and predictability for Federal
                agencies, States, Tribes, the regulated community, and the public. This
                final rule is intended to ensure that the agencies operate within the
                scope of the Federal government's authority over navigable waters under
                the CWA and the Commerce Clause of the U.S. Constitution.
                B. History of This Rulemaking
                1. The Clean Water Act
                 Congress amended the Federal Water Pollution Control Act (FWPCA),
                or the CWA as it is commonly called,\1\ in 1972 to address longstanding
                concerns regarding the quality of the nation's waters and the federal
                government's ability to address those concerns under existing law.
                Prior to 1972, the ability to control and redress water pollution in
                the nation's waters largely fell to the Corps under the Rivers and
                Harbors Act of 1899 (RHA). While much of that statute focused on
                restricting obstructions to navigation on the nation's major waterways,
                section 13 of the RHA made it unlawful to discharge refuse ``into any
                navigable water of the United States, or into any tributary of any
                navigable water from which the same shall float or be washed into such
                navigable water.'' \2\ 33 U.S.C. 407. Congress had also enacted the
                Water Pollution Control Act of 1948, Public Law 80-845, 62 Stat. 1155
                (June 30, 1948), to address interstate water pollution, and
                subsequently amended that statute in 1956 (giving the statute its
                current formal name), 1961, and 1965. The early versions of the CWA
                promoted the development of pollution abatement programs, required
                States to develop water quality standards, and authorized the Federal
                government to bring enforcement actions to abate water pollution.
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                 \1\ The FWPCA is commonly referred to as the CWA following the
                1977 amendments to the FWPCA. Public Law 95-217, 91 Stat. 1566
                (1977). For ease of reference, the agencies will generally refer to
                the FWPCA in this notice as the CWA or the Act.
                 \2\ The term ``navigable water of the United States'' is a term
                of art used to refer to waters subject to federal jurisdiction under
                the RHA. See, e.g., 33 CFR 329.1. The term is not synonymous with
                the phrase ``waters of the United States'' under the CWA, see id.,
                and the general term ``navigable waters'' has different meanings
                depending on the context of the statute in which it is used. See,
                e.g., PPL Montana, LLC v. Montana, 565 U.S. 576, 591-93 (2012).
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                 These early statutory efforts, however, proved inadequate to
                address the decline in the quality of the nation's waters, see City of
                Milwaukee v. Illinois, 451 U.S. 304, 310 (1981), so Congress performed
                a ``total restructuring'' and ``complete rewriting'' of the existing
                statutory framework in 1972, id. at 317 (quoting legislative history of
                1972 amendments). That restructuring resulted in the enactment of a
                comprehensive scheme (including voluntary as well as regulatory
                programs) designed to prevent, reduce, and eliminate pollution in the
                nation's waters generally, and to regulate the discharge of pollutants
                into navigable waters specifically. See, e.g., S.D. Warren Co. v. Maine
                Bd. of Envtl. Prot., 547 U.S. 370, 385 (2006) (noting that ``the Act
                does not stop at controlling the `addition of pollutants,' but deals
                with `pollution' generally'').
                 The objective of the new statutory scheme was ``to restore and
                maintain the chemical, physical, and biological integrity of the
                Nation's waters.'' 33 U.S.C. 1251(a). In order to meet that objective,
                Congress declared two national goals: (1) ``that the discharge of
                pollutants into the navigable waters be eliminated by 1985''; and (2)
                ``that wherever attainable, an interim goal of water quality which
                provides for the protection and propagation of fish, shellfish, and
                wildlife and provides for recreation in and on the water be achieved by
                July 1, 1983 . . . .'' Id. at 1251(a)(1)-(2).
                 Congress also established several key policies that direct the work
                of the agencies to effectuate those goals. For example, Congress
                declared as a national policy ``that the discharge of toxic pollutants
                in toxic amounts be prohibited; . . . that Federal financial assistance
                be provided to construct publicly owned waste treatment works; . . .
                that areawide waste treatment management planning processes be
                developed and implemented to assure adequate control of sources of
                pollutants in each State; . . . [and] that programs for the control of
                nonpoint sources of pollution be developed and implemented in an
                expeditious manner so as to enable the goals of this Act to be met
                through the control of both point and nonpoint sources of pollution.''
                33 U.S.C. 1251(a)(3)-(7).
                 Congress provided a major role for the States in implementing the
                CWA, balancing the preservation of the traditional power of States to
                regulate land and water resources within their borders with the need
                for a national water quality regulation. For example, the statute
                highlighted ``the policy of the Congress to recognize, preserve, and
                protect the primary responsibilities and rights of States to prevent,
                reduce, and eliminate pollution'' and ``to plan the development and use
                . . . of land and water resources.'' 33 U.S.C. 1251(b). Congress also
                declared as a national policy that States manage the major construction
                grant program and implement the core permitting programs authorized by
                the statute, among other responsibilities. Id. Congress added that
                ``[e]xcept as expressly provided in this Act, nothing in this Act shall
                . . . be construed as impairing or in any manner affecting any right or
                jurisdiction of the States with respect to the waters (including
                boundary waters) of such States.'' Id. at 1370.\3\ Congress
                [[Page 22253]]
                pledged the Federal government to provide technical support and
                financial aid to the States ``in connection with the prevention,
                reduction, and elimination of pollution.'' Id. at 1251(b).
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                 \3\ 33 U.S.C. 1370 also prohibits authorized States from
                adopting any limitations, prohibitions, or standards that are less
                stringent than required by the CWA.
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                 To carry out these policies, Congress broadly defined ``pollution''
                to mean ``the man-made or man-induced alteration of the chemical,
                physical, biological, and radiological integrity of water,'' 33 U.S.C.
                1362(19), in keeping with the objective of the Act ``to restore and
                maintain the chemical, physical, and biological integrity of the
                Nation's waters.'' Id. at 1251(a). Congress then crafted a non-
                regulatory statutory framework to provide technical and financial
                assistance to the States to prevent, reduce, and eliminate pollution in
                the nation's waters generally. For example, section 105 of the Act,
                ``Grants for research and development,'' authorized the EPA ``to make
                grants to any State, municipality, or intermunicipal or interstate
                agency for the purpose of assisting in the development of any project
                which will demonstrate a new or improved method of preventing,
                reducing, and eliminating the discharge into any waters of pollutants
                from sewers which carry storm water or both storm water and
                pollutants.'' Id. at 1255(a)(1) (emphasis added). Section 105 also
                authorized the EPA ``to make grants to any State or States or
                interstate agency to demonstrate, in river basins or portions thereof,
                advanced treatment and environmental enhancement techniques to control
                pollution from all sources . . . including nonpoint sources, . . .
                [and] . . . to carry out the purposes of section 301 of this Act . . .
                for research and demonstration projects for prevention of pollution of
                any waters by industry including, but not limited to, the prevention,
                reduction, and elimination of the discharge of pollutants.'' Id. at
                1255(b)-(c) (emphasis added); see also id. at 1256(a) (authorizing the
                EPA to issue ``grants to States and to interstate agencies to assist
                them in administering programs for the prevention, reduction, and
                elimination of pollution'').
                 Section 108, ``Pollution control in the Great Lakes,'' authorized
                the EPA to enter into agreements with any State to develop plans for
                the ``elimination or control of pollution, within all or any part of
                the watersheds of the Great Lakes.'' 33 U.S.C. 1258(a) (emphasis
                added); see also id. at 1268(a)(3)(C) (defining the ``Great Lakes
                System'' as ``all the streams, rivers, lakes, and other bodies of water
                within the drainage basin of the Great Lakes'') (emphasis added).
                Similar broad pollution control programs were created for other major
                watersheds, including, for example, the Chesapeake Bay, see id. at
                1267(a)(3), Long Island Sound, see id. at 1269(c)(2)(D), and Lake
                Champlain, see id. at 1270(g)(2). Some commenters noted that the Great
                Lakes, Long Island Sound, Chesapeake Bay, and Lake Champlain are waters
                of the United States to which regulatory programs apply, and that the
                purpose of the technical assistance and grants in the cited sections is
                to assist states and others in achieving the requirements of the Act.
                The agencies agree that these waters are waters of the United States,
                but the emphasized language in the cited provisions above makes clear
                that these provisions address all bodies of water in the watersheds of
                the Great Lakes, Long Island Sound, Chesapeake Bay, and Lake Champlain,
                regardless of the jurisdictional status of those waters.
                 In addition to the Act's non-regulatory measures to control
                pollution of the nation's waters generally, Congress created a federal
                regulatory permitting program designed to address the discharge of
                pollutants into a subset of those waters identified as ``navigable
                waters,'' defined as ``the waters of the United States,'' 33 U.S.C.
                1362(7). Section 301 contains the key regulatory mechanism: ``Except as
                in compliance with this section and sections 302, 306, 307, 318, 402,
                and 404 of this Act, the discharge of any pollutant by any person shall
                be unlawful.'' Id. at 1311(a). A ``discharge of a pollutant'' is
                defined to include ``any addition of any pollutant to navigable waters
                from any point source,'' defined to mean ``any discernible, confined
                and discrete conveyance'' such as a pipe or ditch. Id. at 1362(12),
                (14). The term ``pollutant'' means ``dredged spoil, solid waste,
                incinerator residue, sewage, garbage, sewage sludge, munitions,
                chemical wastes, biological materials, radioactive materials, heat,
                wrecked or discarded equipment, rock, sand, cellar dirt and industrial,
                municipal, and agricultural waste discharged into water.'' Id. at
                1362(6). Thus, it is unlawful to discharge pollutants into the ``waters
                of the United States'' from a point source unless the discharge is in
                compliance with certain enumerated sections of the CWA, including
                obtaining authorization pursuant to the section 402 National Pollutant
                Discharge Elimination System (NPDES) permit program or the section 404
                dredged or fill material permit program. See id. at 1342, 1344.
                Congress therefore intended to achieve the Act's objective ``to restore
                and maintain the chemical, physical, and biological integrity of the
                Nation's waters'' by addressing pollution of all waters via non-
                regulatory means and federally regulating the discharge of pollutants
                to the subset of waters identified as ``navigable waters.'' \4\
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                 \4\ Members of Congress were aware when they drafted the 1972
                CWA amendments that different types of the Nation's waters would be
                subject to different degrees of federal control. For instance, in
                House debate regarding a proposed and ultimately failed amendment to
                prohibit the discharge of pollutants to groundwater in addition to
                navigable waters, Representative Don H. Clausen stated, ``Mr.
                Chairman, in the early deliberations within the committee which
                resulted in the introduction of H.R. 11896, a provision for ground
                waters . . . was thoroughly reviewed and it was determined by the
                committee that there was not sufficient information on ground waters
                to justify the types of controls that are required for navigable
                waters . . . . I refer the gentleman to the objectives of this act
                as stated in section 101(a). The objective of this act is to restore
                and maintain the chemical, physical, and biological integrity of the
                Nation's waters. I call your attention to the fact that this does
                not say the Nation's [`]navigable waters,' `interstate waters,' or
                `intrastate waters.' It just says `waters.' This includes ground
                waters.'' 118 Cong. Rec. at 10,667 (daily ed. March 28, 1972).
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                 Many commenters on this rulemaking agreed with this summary of the
                CWA, stating that it accurately characterizes the full scope of the Act
                and the thoughtful, holistic approach Congress enacted to address water
                pollution in this country. Many commenters stated that Congress
                developed both regulatory and non-regulatory approaches for addressing
                water pollution, whereby ``navigable waters'' are subject to federal
                regulatory requirements under the CWA but many other classes of the
                ``nation's waters'' are not. Some commenters disagreed that the CWA
                distinguishes between the ``nation's waters'' and a subset of those
                waters known as the ``navigable waters.'' Many of these commenters
                suggested that the agencies' interpretation is not supported by the
                text or structure of the Act and is based instead on
                mischaracterizations of the Act's provisions. Some commenters argued
                that the two terms are synonymous under the Act, and others stated that
                the non-regulatory provisions of the CWA were intended to complement
                the regulatory requirements applicable to waters of the United States,
                as opposed to addressing a separate category of waters. Fundamental
                principles of statutory interpretation support the agencies'
                recognition of a distinction between the ``nation's waters'' and
                ``navigable waters.'' As the Supreme Court has observed, ``[w]e assume
                that Congress used two terms because it intended each term to have a
                particular, nonsuperfluous meaning.'' Bailey v. United States, 516 U.S.
                137, 146 (1995)
                [[Page 22254]]
                (recognizing the canon of statutory construction against superfluity).
                Further, ``the words of a statute must be read in their context and
                with a view to their place in the overall statutory scheme.'' FDA v.
                Brown & Williamson Tobacco Corp., 529 U.S. 120, 133 (2000) (internal
                quotation marks and citation omitted); see also United Sav. Ass'n of
                Texas v. Timbers of Inwood Forest Associates, 484 U.S. 365, 371
                (``Statutory construction . . . is a holistic endeavor. A provision
                that may seem ambiguous in isolation is often clarified by the
                remainder of the statutory scheme--because the same terminology is used
                elsewhere in a context that makes its meaning clear[.]'') (citation
                omitted). Here, the non-regulatory sections of the CWA reveal Congress'
                intent to restore and maintain the integrity of the nation's waters
                using federal assistance to support State and local partnerships to
                control pollution in the nation's waters and a federal regulatory
                prohibition on the discharge of pollutants to the navigable waters. If
                Congress had intended the terms to be synonymous, it would have used
                identical terminology. Instead, Congress chose to use separate terms,
                and the agencies are instructed by the Supreme Court to presume
                Congress did so intentionally.
                 Under the enacted statutory scheme, the States are primarily
                responsible for developing water quality standards for waters of the
                United States within their borders and reporting on the condition of
                those waters to the EPA every two years. 33 U.S.C. 1313, 1315. States
                must develop total maximum daily loads (TMDLs) for waters that are not
                meeting established water quality standards and must submit those TMDLs
                to the EPA for approval. Id. at 1313(d). States also have authority to
                issue water quality certifications or waive certification for every
                federal permit or license issued within their borders that may result
                in a discharge to navigable waters. Id. at 1341.
                 These same regulatory authorities can be assumed by Indian tribes
                under section 518 of the CWA, which authorizes the EPA to treat
                eligible Indian tribes with reservations in a manner similar to States
                for a variety of purposes, including administering each of the
                principal CWA regulatory programs. 33 U.S.C. 1377(e). In addition,
                States and Tribes retain authority to protect and manage the use of
                those waters that are not navigable waters under the CWA. See, e.g.,
                id. at 1251(b), 1251(g), 1370, 1377(a). At this time, forty-seven
                States administer portions of the CWA section 402 permit program for
                those waters of the United States within their boundaries,\5\ and two
                States (Michigan and New Jersey) administer the section 404 permit
                program for those waters that are assumable by States pursuant to
                section 404(g). Several additional states are exploring the possibility
                of assuming the section 404 permit program. At present, no Tribes
                administer the section 402 or 404 programs, although some are exploring
                the possibility. For additional information regarding State and tribal
                programs, see the Resource and Programmatic Assessment for the final
                rule.
                ---------------------------------------------------------------------------
                 \5\ Three States (Massachusetts, New Hampshire, and New Mexico)
                do not currently administer any part of the CWA section 402 program.
                ---------------------------------------------------------------------------
                2. Regulatory History
                 In May 1973, the EPA issued its first set of regulations to
                implement the new NPDES permit program established in the 1972 CWA
                amendments. Those regulations defined the phrase ``navigable waters''
                as:
                 All navigable waters of the United States;
                 Tributaries of navigable waters of the United States;
                 Interstate waters;
                 Intrastate lakes, rivers, and streams which are utilized
                by interstate travelers for recreational or other purposes;
                 Intrastate lakes, rivers, and streams from which fish or
                shellfish are taken and sold in interstate commerce; and
                 Intrastate lakes, rivers, and streams which are utilized
                for industrial purposes by industries in interstate commerce.
                38 FR 13528, 13529 (May 22, 1973) (codified at 40 CFR 125.1 (1973)).
                 In 1974, the Corps issued its first set of regulations defining
                ``waters of the United States'' for the purpose of implementing section
                404 of the CWA as well as sections 9, 10, 11, 13, and 14 of the RHA.
                These regulations reaffirmed the Corps' view that its dredged and fill
                jurisdiction under section 404 was the same as its traditional
                jurisdiction under the RHA. See 39 FR 12115, 12119 (Apr. 3, 1974)
                (codified at 33 CFR 209.120). Specifically, the Corps defined the
                ``waters of the United States'' as waters that ``are subject to the ebb
                and flow of the tide, and/or are presently, or have been in the past,
                or may be in the future susceptible for use for purposes of interstate
                or foreign commerce.'' Id.
                 Environmental organizations challenged the Corps' 1974 regulation
                in the U.S. District Court for the District of Columbia, arguing that
                the Corps' definition of ``navigable waters'' was inadequate because it
                did not include tributaries or coastal marshes above the mean high tide
                mark or wetlands above the ordinary high water mark. The District Court
                held that the term ``navigable waters'' is not limited to the
                traditional tests of navigability and ordered the Corps to revoke its
                definition and publish a new one ``clearly recognizing the full
                regulatory mandate of the Water Act.'' Natural Resources Defense
                Council, Inc. v. Callaway, 392 F. Supp. 685 (D.D.C. 1975).
                 In response to this decision, the Corps issued interim regulations
                in 1975 that defined the term ``navigable waters'' to include
                periodically inundated coastal wetlands contiguous with or adjacent to
                navigable waters, periodically inundated freshwater wetlands contiguous
                with or adjacent to navigable waters, and, as in the EPA's 1973
                regulations, certain intrastate waters based on non-transportation
                impacts on interstate commerce. The Corps revised the definition in
                1977 to encompass traditional navigable waters, tributaries to
                navigable waters, interstate waters, adjacent wetlands to those
                categories of waters, and ``[a]ll other waters'' the ``degradation or
                destruction of which could affect interstate commerce.'' 42 FR 37122,
                37144 (Jul. 19, 1977).
                 The EPA and the Corps have maintained separate regulations defining
                the statutory term ``waters of the United States,'' but the text of the
                regulations has been virtually identical starting in 1986.\6\ In 1986,
                for example, the Corps consolidated and recodified its regulations to
                align with clarifications that the EPA had previously promulgated. See
                51 FR 41206 (Nov. 13, 1986). While the Corps stated in 1986 that the
                recodified regulation neither reduced nor expanded jurisdiction, its
                previous exclusion for ditches was moved from the regulatory text to
                the final rule preamble. Id. at 41216-17. And the Corps added to the
                preamble what later became known as the ``Migratory Bird Rule,'' which
                claimed jurisdiction over any waters which are or may be used by birds
                protected by migratory bird treaties, waters which may be used as
                habitat for birds flying across state lines, waters which may be used
                by endangered species, and waters used to
                [[Page 22255]]
                irrigate crops sold in interstate commerce. Id. at 41217.
                ---------------------------------------------------------------------------
                 \6\ For convenience, the agencies generally refer to the Corps'
                regulations throughout this notice at 33 CFR 328.3. The EPA's
                codification of the definition of ``waters of the United States'' is
                found at 40 CFR 110.1, 112.2, 116.3, 117.1, 122.2, 230.3, 232.2,
                300.5, 302.3, 401.11, and Appendix E to Part 300. This final rule
                also codifies the definition of ``waters of the United States'' in a
                new section 120.2.
                ---------------------------------------------------------------------------
                 The 1986 regulatory text identified the following as waters of the
                United States:
                 All traditional navigable waters,\7\ interstate waters,
                and the territorial seas;
                ---------------------------------------------------------------------------
                 \7\ ``Traditional navigable waters'' (or waters that are
                traditionally understood as navigable) refers to all waters which
                are currently used, were used in the past, or may be susceptible to
                use in interstate or foreign commerce, including all waters subject
                to the ebb and flow of the tide.
                ---------------------------------------------------------------------------
                 All impoundments of jurisdictional waters;
                 All ``other waters'' such as lakes, ponds, and sloughs the
                ``use, degradation or destruction of which could affect interstate or
                foreign commerce'';
                 Tributaries of traditional navigable waters, interstate
                waters, impoundments, or ``other waters''; and,
                 Wetlands adjacent to traditional navigable waters,
                interstate waters, the territorial seas, impoundments, tributaries, or
                ``other waters'' (other than waters that are themselves wetlands).
                33 CFR 328.3(a)(1)-(7) (1987). The 1986 regulation also excluded
                ``waste treatment systems'' from the definition of ``waters of the
                United States,'' consistent with the EPA's regulatory definition. Id.
                at 328.3 (a)(7), (b) (1987); see also 44 FR 32854 (June 7, 1979).
                 On August 25, 1993, the agencies amended the regulatory definition
                of ``waters of the United States'' to categorically exclude ``prior
                converted croplands.'' 58 FR 45008, 45031 (Aug. 25, 1993) (``1993
                Rule'') (codified at 33 CFR 328.3(a)(8) (1994)). The stated purpose of
                the amendment was to promote ``consistency among various federal
                programs affecting wetlands,'' in particular the Food Security Act of
                1985 (FSA) programs implemented by the U.S. Department of Agriculture
                (USDA) and the CWA programs implemented by the agencies.\8\ 58 FR
                45031. The agencies did not include a definition of ``prior converted
                cropland'' in the text of the Code of Federal Regulations but noted in
                the preamble to the 1993 Rule that the term was defined at that time by
                the USDA National Food Security Act Manual (NFSAM). Id. The agencies at
                that time also declined to establish regulatory text specifying when
                the prior converted cropland designation is no longer applicable. In
                the preamble to the 1993 Rule, the agencies stated that ``[t]he Corps
                and EPA will use the [Natural Resources Conservation Service's]
                provisions on `abandonment,' thereby ensuring that PC cropland that is
                abandoned within the meaning of those provisions and which exhibit[s]
                wetlands characteristics will be considered wetlands subject to Section
                404 regulation.'' Id. at 45034. The agencies summarized these
                abandonment provisions by explaining that prior converted cropland
                which meets wetland criteria is considered to be abandoned unless: At
                least once in every five years the area has been used for the
                production of an agricultural commodity, or the area has been used and
                will continue to be used for the production of an agricultural
                commodity in a commonly used rotation with aquaculture, grasses,
                legumes, or pasture production. Id.
                ---------------------------------------------------------------------------
                 \8\ Title XII of the Food Security Act of 1985, as amended,
                encourages participants in USDA programs to adopt land management
                measures by linking eligibility for USDA program benefits to farming
                practices on highly erodible land and wetlands (i.e., the wetland
                conservation provisions). USDA policy guidance regarding
                implementation of the wetland conservation provisions is found in
                the current edition of the Natural Resource Conservation Service
                National Food Security Act Manual (NFSAM), including the procedures
                for how to delineate wetlands and make wetland determinations in
                accordance with Subpart C of 7 CFR part 12. Due to the unique
                statutory provisions of the FSA, USDA wetland determinations may
                identify certain areas as exempt under the 1985 Act but remain
                subject to the requirements of the CWA. To avoid potential
                confusion, USDA clearly informs program participants that USDA
                wetland determinations are for purposes of implementing the wetland
                conservation provisions only, and that participants should contact
                the Corps for clarification as to whether a particular activity will
                require a CWA section 404 permit.
                ---------------------------------------------------------------------------
                 Congress amended the FSA wetland conservation provisions in 1996 to
                state that USDA certifications of eligibility for program benefits
                (e.g., determinations by the Natural Resources Conservation Service
                (NRCS) that particular areas constitute prior converted cropland)
                ``shall remain valid and in effect as long as the area is devoted to an
                agricultural use or until such time as the person affected by the
                certification requests review of the certification by the Secretary [of
                Agriculture].'' Public Law 104-127, 322(a)(4), 110 Stat. 888 (1996); 16
                U.S.C. 3822(a)(4). Thus, for purposes of farm program eligibility, the
                1996 amendments designate as prior converted cropland those areas that
                may not have qualified for the CWA exclusion under the abandonment
                principles from the 1993 preamble, so long as such areas remain in
                agricultural use. The agencies did not update their prior converted
                cropland regulations for purposes of the CWA following the 1996
                amendments to wetland conservation provisions of the FSA, as those
                regulations neither defined prior converted cropland nor specified when
                a valid prior converted cropland determination might cease to be valid.
                However, in 2005, the Army and USDA issued a joint Memorandum to the
                Field (the 2005 Memorandum) in an effort to again align the CWA section
                404 program with the FSA amendments.\9\ The 2005 Memorandum provided
                that a ``certified [prior converted] determination made by [USDA]
                remains valid as long as the area is devoted to an agricultural use. If
                the land changes to a non-agricultural use, the [prior converted]
                determination is no longer applicable and a new wetland determination
                is required for CWA purposes.'' 2005 Memorandum at 4.
                ---------------------------------------------------------------------------
                 \9\ Natural Resources Conservation Service and U.S. Army Corps
                of Engineers. Memorandum to the Field on Guidance on Conducting
                Wetland Determinations for the Food Security Act of 1985 and section
                404 of the Clean Water Act (Feb. 25, 2005), available at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2508.
                ---------------------------------------------------------------------------
                 The 2005 Memorandum did not clearly address the abandonment
                principle that the agencies had been implementing since the 1993
                rulemaking. The change in use policy was also never promulgated as a
                rule and was declared unlawful by one district court because it
                effectively modified the 1993 preamble language without any rulemaking
                process. New Hope Power Co. v. U.S. Army Corps of Eng'rs, 746 F. Supp.
                2d 1272, 1282 (S.D. Fla. 2010).
                3. U.S. Supreme Court Decisions
                 From the earliest rulemaking efforts following adoption of the 1972
                CWA amendments, to the agencies' most recent attempt to define ``waters
                of the United States'' in 2015, the sparse statutory definition has
                spurred substantial litigation testing the meaning of the phrase.
                Hundreds of cases and dozens of courts have attempted to discern the
                intent of Congress when crafting the phrase. See, e.g., Rapanos v.
                United States, 547 U.S. 715, 739 (2006) (Scalia, J., plurality)
                (briefly summarizing case history). The federal courts have established
                different analytical frameworks to interpret the phrase, and the
                applicable test may differ from State to State. See, e.g., Memorandum
                from Dick Pedersen, President of the Environmental Council of the
                States (ECOS) of September 11, 2014, Concerning Waters of the United
                States under the Act at 2-23 (2014) (hereinafter, the ``ECOS
                Memorandum''), available at http://acoel.org/file.axd?file=2014%2f9%2fWaters+of+the+U+S+Final+9_11_14.pdf
                (summarizing case history following Rapanos).
                 As part of this complex litigation history, three key U.S. Supreme
                Court decisions have interpreted the term
                [[Page 22256]]
                ``waters of the United States'' and its implementing regulations and
                serve as guideposts for the agencies' interpretation of the phrase
                ``waters of the United States.'' In 1985, the Supreme Court deferred to
                the Corps' assertion of jurisdiction over wetlands actually abutting a
                traditional navigable water in Michigan, stating that adjacent wetlands
                may be regulated as waters of the United States because they are
                ``inseparably bound up'' with navigable waters and ``in the majority of
                cases'' have ``significant effects on water quality and the aquatic
                ecosystem'' in those waters. United States v. Riverside Bayview Homes,
                474 U.S. 121, 131-35 & n.9 (1985). The Court recognized that ``[i]n
                determining the limits of its power to regulate discharges under the
                Act, the Corps must necessarily choose some point at which water ends
                and land begins . . . . Where on this continuum to find the limit of
                `waters' is far from obvious.'' Id. at 132. The Court acknowledged the
                ``inherent difficulties of defining precise bounds to regulable
                waters,'' and deferred to the agencies' interpretation that the close
                ecological relationship between adjacent wetlands and traditional
                navigable waters provided a legal justification for treating wetlands
                as waters. Id. at 134. The Court also ``conclude[d] that a definition
                of `waters of the United States' encompassing all wetlands adjacent to
                other bodies of water over which the Corps has jurisdiction is a
                permissible interpretation of the Act.'' Id. at 135.
                 The Supreme Court again addressed the definition of ``waters of the
                United States'' in Solid Waste Agency of Northern Cook County v. U.S.
                Army Corps of Engineers, 531 U.S. 159 (2001) (SWANCC). In SWANCC, the
                Court rejected a claim of federal jurisdiction over nonnavigable,
                isolated, intrastate ponds that lack a sufficient connection to
                traditional navigable waters, noting that the term ``navigable'' must
                be given meaning within the context and application of the statute. Id.
                The Court held that interpreting the statute to extend to nonnavigable,
                isolated, intrastate ponds that lack a sufficient connection to
                traditional navigable waters would invoke the outer limits of Congress'
                power under the Commerce Clause. Id. at 172. Where an administrative
                interpretation of a statute presses against the outer limits of
                Congress' constitutional authority, the Court explained, it expects a
                clear statement from Congress that it intended that result, and even
                more so when the broad interpretation authorizes federal encroachment
                upon a traditional State power. Id. The CWA contains no such clear
                statement. Id. at 174.
                 In January 2003, the EPA and the Corps issued joint guidance
                interpreting the Supreme Court decision in SWANCC.\10\ The guidance
                indicated that SWANCC focused on nonnavigable, isolated, intrastate
                waters, and called for field staff to coordinate with their respective
                Corps or EPA Headquarters on jurisdictional determinations that
                asserted jurisdiction over such waters. The agencies at that time
                focused their interpretation of SWANCC to its facts, and applied the
                decision narrowly as restricting the exercise of federal jurisdiction
                solely based on the Migratory Bird Rule.
                ---------------------------------------------------------------------------
                 \10\ See U.S. EPA and U.S. Army Corps of Engineers. Legal
                Memoranda Regarding Solid Waste Agency of Northern Cook County
                (SWANCC) v. United States (Jan. 15, 2003), available at https://www.epa.gov/sites/production/files/2016-04/documents/swancc_guidance_jan_03.pdf.
                ---------------------------------------------------------------------------
                 The Court most recently interpreted the term ``waters of the United
                States'' in Rapanos v. United States, 547 U.S. 715 (2006). Rapanos
                involved two consolidated cases in which the CWA had been applied to
                wetlands located near man-made ditches that were ultimately connected
                to traditional navigable waters. All members of the Court agreed that
                the term ``waters of the United States'' encompasses some waters that
                are not navigable in the traditional sense.
                 A four-Justice plurality interpreted the term ``waters of the
                United States'' to ``include[ ] only those relatively permanent,
                standing or continuously flowing bodies of water `forming geographic
                features' that are described in ordinary parlance as `streams[,] . . .
                oceans, rivers, [and] lakes,' '' Rapanos, 547 U.S. at 739 (Scalia, J.,
                plurality) (quoting Webster's New International Dictionary 2882 (2d ed.
                1954)), and ``wetlands with a continuous surface connection'' to a
                ``relatively permanent body of water connected to traditional
                interstate navigable waters.'' Id. at 742. The plurality explained that
                ``[w]etlands with only an intermittent, physically remote hydrologic
                connection to `waters of the United States' do not implicate the
                boundary-drawing problem of Riverside Bayview,'' and thus do not have
                the ``necessary connection'' to covered waters that triggers CWA
                jurisdiction. Id. at 742. The plurality also noted that its reference
                to ``relatively permanent'' waters did ``not necessarily exclude
                streams, rivers, or lakes that might dry up in extraordinary
                circumstances, such as drought,'' or ``seasonal rivers, which contain
                continuous flow during some months of the year but no flow during dry
                months.'' Id. at 732 n.5 (emphasis in original).
                 In a concurring opinion, Justice Kennedy took a different approach,
                concluding that ``to constitute `navigable waters' under the Act, a
                water or wetland must possess a `significant nexus' to waters that are
                or were navigable in fact or that could reasonably be so made.''
                Rapanos, 547 U.S. at 759 (Kennedy, J., concurring in the judgment)
                (citing SWANCC, 531 U.S. at 167, 172). He stated that adjacent wetlands
                possess the requisite significant nexus if the wetlands ``either alone
                or in combination with similarly situated lands in the region,
                significantly affect the chemical, physical, and biological integrity
                of other covered waters more readily understood as `navigable.' '' Id.
                at 780.
                 Following Rapanos, on June 7, 2007, the agencies issued joint
                guidance entitled ``Clean Water Act Jurisdiction Following the U.S.
                Supreme Court's Decision in Rapanos v. United States and Carabell v.
                United States'' to address the waters at issue in that decision. The
                guidance did not change the codified definition of ``waters of the
                United States.'' The guidance indicated that the agencies would assert
                jurisdiction over traditional navigable waters and their adjacent
                wetlands, relatively permanent nonnavigable tributaries of traditional
                navigable waters and wetlands that abut them, nonnavigable tributaries
                that are not relatively permanent if they have a significant nexus with
                a traditional navigable water, and wetlands adjacent to nonnavigable
                tributaries that are not relatively permanent if they have a
                significant nexus with a traditional navigable water. The guidance was
                reissued with minor changes on December 2, 2008 (hereinafter, the
                ``Rapanos Guidance'').\11\ After issuance of the Rapanos Guidance,
                Members of Congress, developers, farmers, State and local governments,
                environmental organizations, energy companies, and others asked the
                agencies to replace the guidance with a regulation that would provide
                clarity and certainty regarding the scope of the waters federally
                regulated under the CWA.
                ---------------------------------------------------------------------------
                 \11\ See U.S. EPA and U.S. Army Corps of Engineers. Clean Water
                Act Jurisdiction Following the U.S. Supreme Court's Decision in
                Rapanos v. United States & Carabell v. United States at 1 (Dec. 2,
                2008) (``Rapanos Guidance''), available at https://www.epa.gov/sites/production/files/2016-02/documents/cwa_jurisdiction_following_rapanos120208.pdf.
                ---------------------------------------------------------------------------
                 Since Rapanos, litigation has continued to confuse the regulatory
                landscape. See, e.g., ECOS Memorandum at 2-23. The Supreme
                [[Page 22257]]
                Court also has twice weighed in on topics related to the agencies'
                implementation of their authorities under the CWA to help clarify
                federal authority in this area. In each case, members of the Court
                noted the longstanding confusion regarding the scope of federal
                jurisdiction under the CWA and the importance of providing clear
                guidance to the regulated community. In 2012, for example, the Supreme
                Court unanimously rejected the EPA's longstanding position that
                compliance orders issued under the CWA to force property owners to
                restore wetlands are not judicially reviewable as final agency actions.
                See Sackett v. EPA, 566 U.S. 120, 131 (2012). In a concurring opinion,
                Justice Alito referred to the jurisdictional reach of the CWA as
                ``notoriously unclear'' and noted that the Court's decision provided
                only ``a modest measure of relief.'' Id. at 133 (Alito, J., concurring)
                (``For 40 years, Congress has done nothing to resolve this critical
                ambiguity, and the EPA has not seen fit to promulgate a rule providing
                a clear and sufficiently limited definition of the phrase [`waters of
                the United States']'').
                 In 2016, the Supreme Court in a unanimous opinion rejected the
                Corps' longstanding position that jurisdictional determinations issued
                by the Corps were not judicially reviewable as final agency actions.
                Writing for the Court, the Chief Justice recognized that it ``is often
                difficult to determine whether a particular piece of property contains
                waters of the United States, but there are important consequences if it
                does.'' U.S. Army Corps of Eng'rs v. Hawkes Co., 136 S. Ct. 1807, 1812
                (2016). Given those important consequences, the Court held that
                jurisdictional determinations are subject to immediate judicial review
                when made. Justice Kennedy authored a concurring opinion, ``not to
                qualify what the Court says but to point out that, based on the
                Government's representations in this case, the reach and systemic
                consequences of the Clean Water Act remain a cause for concern.'' Id.
                at 1816-17 (referring to the ``ominous reach'' of the Act). On remand,
                the lower court found that the Corps' assertion of jurisdiction over a
                peat farm more than 90 miles from the nearest traditional navigable
                water based on the ``significant nexus'' test described in the
                agencies' Rapanos Guidance was ``arbitrary and capricious.'' Hawkes Co.
                v. U.S. Army Corps of Eng'rs, No. 13-107 ADM/TNL, 2017 U.S. Dist. LEXIS
                10680 at *33 (D. Minn. Jan. 24, 2017).
                4. The 2015 Rule
                 On June 29, 2015, the agencies issued a final rule (80 FR 37054)
                amending various portions of the CFR that set forth a definition of
                ``waters of the United States,'' a term contained in the CWA's
                definition of ``navigable waters,'' 33 U.S.C. 1362(7). One of the
                stated purposes of the 2015 Rule was to ``increase CWA program
                predictability and consistency by clarifying the scope of `waters of
                the United States' protected under the Act.'' 80 FR 37054. The 2015
                Rule defined the geographic scope of the CWA by placing waters into
                three categories: (A) Waters that are categorically ``jurisdictional by
                rule'' in all instances (i.e., without the need for any additional
                analysis); (B) waters that are subject to case-specific analysis to
                determine whether they are jurisdictional; and (C) waters that are
                categorically excluded from jurisdiction. Waters considered
                ``jurisdictional by rule'' included (1) waters which are currently
                used, were used in the past, or may be susceptible to use in interstate
                or foreign commerce, including all waters which are subject to the ebb
                and flow of the tide; (2) interstate waters, including interstate
                wetlands; (3) the territorial seas; (4) impoundments of waters
                otherwise identified as jurisdictional; (5) tributaries of the first
                three categories of ``jurisdictional by rule'' waters; and (6) waters
                adjacent to a water identified in the first five categories of
                ``jurisdictional by rule'' waters, including ``wetlands, ponds, lakes,
                oxbows, impoundments, and similar waters.'' See 80 FR 37104.
                 The 2015 Rule relied on a scientific literature review--the
                Connectivity Report \12\--to support exerting federal jurisdiction over
                certain waters. See 80 FR 37065 (``[T]he agencies interpret the scope
                of `waters of the United States' protected under the CWA based on the
                information and conclusions in the [Connectivity] Report . . . .'').
                Although the agencies acknowledged that science cannot dictate where to
                draw the line of federal jurisdiction, see, e.g., id. at 37060,
                notwithstanding that qualifier, the agencies relied on the Connectivity
                Report extensively in establishing the 2015 Rule's definition of
                ``waters of the United States.'' See id. at 37057 (``The [Connectivity]
                Report provides much of the technical basis for [the] rule.'').
                ---------------------------------------------------------------------------
                 \12\ U.S. EPA. Connectivity of Streams and Wetlands to
                Downstream Waters: A Review and Synthesis of the Scientific Evidence
                (Jan. 2015) (EPA/600/R-14/475F).
                ---------------------------------------------------------------------------
                 The 2015 Rule added new definitions of key terms such as
                ``tributaries'' and revised previous definitions of terms such as
                ``adjacent'' (by adding a new definition of ``neighboring'' that is
                used in the definition of ``adjacent'') that would determine whether
                waters were ``jurisdictional by rule.'' See 80 FR 37105. Specifically,
                a ``tributary'' under the 2015 Rule is a water that contributes flow,
                either directly or through another water, to a water identified in the
                first three categories of ``jurisdictional by rule'' waters that is
                characterized by the presence of the ``physical indicators'' of a bed
                and banks and an ordinary high water mark. According to the 2015 Rule's
                preamble, ``[t]hese physical indicators demonstrate there is volume,
                frequency, and duration of flow sufficient to create a bed and banks
                and an ordinary high water mark, and thus to qualify as a tributary.''
                Id.\13\ Tributaries under the 2015 Rule could be natural, man-altered,
                or man-made, and do not lose their status as a tributary if, for any
                length, there is one or more constructed breaks (such as bridges,
                culverts, pipes, or dams), or one or more natural breaks (such as
                wetlands along the run of a stream, debris piles, boulder fields, or a
                stream that flows underground) so long as a bed and banks and an
                ordinary high water mark could be identified upstream of the break. Id.
                at 37105-06.
                ---------------------------------------------------------------------------
                 \13\ The 2015 Rule did not delineate jurisdiction specifically
                based on categories with established scientific meanings such as
                ephemeral, intermittent, and perennial waters that are based on the
                source of the water and nature of the flow. See 80 FR 37076 (``Under
                the rule, flow in the tributary may be perennial, intermittent, or
                ephemeral.''). Under the 2015 Rule, tributaries also did not need to
                possess any specific volume, frequency, or duration of flow, or to
                contribute flow to a traditional navigable water in any given year
                or specific time period.
                ---------------------------------------------------------------------------
                 In the 2015 Rule, the agencies did not expressly amend the
                longstanding definition of ``adjacent'' (defined as ``bordering,
                contiguous, or neighboring''), but the agencies added, for the first
                time, a definition of ``neighboring'' that changed the meaning of
                ``adjacent.'' The 2015 Rule defined ``neighboring'' to encompass all
                waters located within 100 feet of the ordinary high water mark of a
                category (1) through (5) ``jurisdictional by rule'' water; all waters
                located within the 100-year floodplain of a category (1) through (5)
                ``jurisdictional by rule'' water and not more than 1,500 feet from the
                ordinary high water mark of such water; all waters located within 1,500
                feet of the high tide line of a category (1) through (3)
                ``jurisdictional by rule'' water; and all waters within 1,500 feet of
                the ordinary high water mark of the Great Lakes. 80 FR 37105. The
                entire water would be considered ``neighboring'' if any portion of it
                lies
                [[Page 22258]]
                within one of these zones. See id. These quantitative measures did not
                appear in the proposed rule and, as discussed in the 2019 Rule and
                below, the agencies concluded that they were not sufficiently supported
                in the administrative record for the final rule.
                 In addition to the six categories of ``jurisdictional by rule''
                waters, the 2015 Rule identified certain waters that would be subject
                to a case-specific analysis to determine if they had a ``significant
                nexus'' to a water that is jurisdictional. 80 FR 37104-05. The first
                category consists of five specific types of waters in specific regions
                of the country: Prairie potholes, Carolina and Delmarva bays, pocosins,
                western vernal pools in California, and Texas coastal prairie wetlands.
                Id. at 37105. The second category consists of all waters located within
                the 100-year floodplain of any category (1) through (3)
                ``jurisdictional by rule'' water and all waters located within 4,000
                feet of the high tide line or ordinary high water mark of any category
                (1) through (5) ``jurisdictional by rule'' water. Id. These
                quantitative measures did not appear in the proposed rule and, as
                discussed in the 2019 Rule and below, the agencies concluded that they
                were not sufficiently supported in the administrative record for the
                final 2015 Rule.
                 The 2015 Rule defined ``significant nexus'' to mean a water,
                including wetlands, that either alone or in combination with other
                similarly situated waters in the region, significantly affected the
                chemical, physical, or biological integrity of a category (1) through
                (3) ``jurisdictional by rule'' water. 80 FR 37106. ``For an effect to
                be significant, it must be more than speculative or insubstantial.''
                Id. The term ``in the region'' meant ``the watershed that drains to the
                nearest'' primary water. Id. This definition was different from the
                test articulated by the agencies in their 2008 Rapanos Guidance. That
                guidance interpreted ``similarly situated'' to include all wetlands
                (not waters) adjacent to the same tributary.
                 Under the 2015 Rule, to determine whether a water, alone or in
                combination with similarly situated waters across the watershed of the
                nearest primary water, had a significant nexus, one had to consider
                nine functions such as sediment trapping, runoff storage, provision of
                life cycle dependent aquatic habitat, and other functions. 80 FR 37106.
                A single function performed by a water, alone or together with
                similarly situated waters in the region, that contributed significantly
                to the chemical, physical, or biological integrity of the nearest
                category (1) through (3) ``jurisdictional by rule'' water was
                sufficient to establish a significant nexus. Id. Taken together, the
                enumeration of the nine functions and the more expansive consideration
                of ``similarly situated waters in the region'' in the 2015 Rule meant
                that the vast majority of water features in the United States may have
                come within the jurisdictional purview of the Federal government.\14\
                ---------------------------------------------------------------------------
                 \14\ ``[T]he vast majority of the nation's water features are
                located within 4,000 feet of a covered tributary, traditional
                navigable water, interstate water, or territorial sea.'' U.S. EPA
                and Department of the Army, Economic Analysis of the EPA-Army Clean
                Water Rule at 11 (May 20, 2015) (``2015 Rule Economic Analysis'')
                (Docket ID: EPA-HQ-OW-2011-0880-20866), available at https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-20866.
                ---------------------------------------------------------------------------
                 The 2015 Rule also retained exclusions from the definition of
                ``waters of the United States'' for prior converted cropland and waste
                treatment systems. 80 FR 37105. In addition, the agencies codified
                several exclusions that, in part, reflected longstanding agency
                practice and added others such as ``puddles'' and ``swimming pools'' in
                response to concerns raised by stakeholders during the public comment
                period on the proposed 2015 Rule. Id. at 37096-98, 37105.
                 Following the 2015 Rule's publication, 31 States \15\ and numerous
                non-state parties, including environmental groups and groups
                representing farming, recreational, forestry, and other interests,
                filed complaints and petitions for review in multiple federal district
                \16\ and appellate \17\ courts challenging the 2015 Rule. In those
                cases, the challengers alleged numerous procedural deficiencies in the
                development and promulgation of the 2015 Rule and substantive
                deficiencies in the 2015 Rule itself. Some challengers argued that the
                2015 Rule was too expansive, while others argued that it excluded too
                many waters from federal jurisdiction.
                ---------------------------------------------------------------------------
                 \15\ Alabama, Alaska, Arizona, Arkansas, Colorado, Florida,
                Georgia, Idaho, Indiana, Kansas, Kentucky, Louisiana, Michigan,
                Mississippi, Missouri, Montana, Nebraska, Nevada, New Mexico
                (Environment Department and State Engineer), North Carolina
                (Department of Environment and Natural Resources), North Dakota,
                Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas,
                Utah, West Virginia, Wisconsin, and Wyoming. Iowa joined the legal
                challenge later in the process, bringing the total to 32 States.
                Colorado, New Mexico, and Wisconsin have since withdrawn from
                litigation against the 2015 Rule.
                 \16\ U.S. District Courts for the Northern and Southern
                Districts of Georgia, District of Minnesota, District of North
                Dakota, Southern District of Ohio, Northern District of Oklahoma,
                Southern District of Texas, District of Arizona, Northern District
                of Florida, District of the District of Columbia, Western District
                of Washington, Northern District of California, and Northern
                District of West Virginia. In April 2019, an additional challenge
                against the 2015 Rule was filed in the U.S. District Court for the
                District of Oregon.
                 \17\ U.S. Courts of Appeals for the Second, Fifth, Sixth,
                Eighth, Ninth, Tenth, Eleventh, and District of Columbia Circuits.
                ---------------------------------------------------------------------------
                 The day before the 2015 Rule's August 28, 2015 effective date, the
                U.S. District Court for the District of North Dakota preliminarily
                enjoined the 2015 Rule in the 13 States that challenged the rule in
                that court.\18\ The district court found those States were ``likely to
                succeed'' on the merits of their challenge to the 2015 Rule because,
                among other reasons, ``it appears likely that the EPA has violated its
                Congressional grant of authority in its promulgation of the Rule.''
                North Dakota v. EPA, 127 F. Supp. 3d 1047, 1051 (D.N.D. 2015). In
                particular, the court noted concern that the 2015 Rule's definition of
                ``tributary'' ``includes vast numbers of waters that are unlikely to
                have a nexus to navigable waters.'' Id. at 1056. Further, the court
                found that ``it appears likely the EPA failed to comply with
                [Administrative Procedure Act (APA)] requirements when promulgating the
                Rule,'' suggesting that certain distance-based measures were not a
                logical outgrowth of the proposal to the 2015 Rule. Id. at 1051, 1058.
                No party sought an interlocutory appeal.
                ---------------------------------------------------------------------------
                 \18\ Alaska, Arizona, Arkansas, Colorado, Idaho, Missouri,
                Montana, Nebraska, Nevada, New Mexico, North Dakota, South Dakota,
                and Wyoming. Iowa's motion to intervene in the case was granted
                after issuance of the preliminary injunction. In May 2019, the court
                granted motions from Colorado and New Mexico to withdraw from the
                litigation and lifted the preliminary injunction as to Colorado and
                New Mexico. Order, North Dakota v. EPA, No. 3:15-cv-00059 (D.N.D.
                May 14, 2019). At the same time, the court stated that the
                preliminary injunction would remain in effect as to a plaintiff-
                intervenor that represents ten counties in New Mexico. The agencies
                filed a motion seeking clarification of the applicability of the
                court's preliminary injunction to those ten counties in New Mexico.
                Defendants' Motion for Clarification Regarding the Scope of the
                Court's Preliminary Injunction, North Dakota v. EPA, No. 3:15-cv-
                00059 (D.N.D. May 24, 2019). As of the time of signature of this
                final rule, that motion is pending before the court.
                ---------------------------------------------------------------------------
                 The numerous petitions for review filed in the courts of appeals
                were consolidated in the U.S. Court of Appeals for the Sixth Circuit.
                In that litigation, State and industry petitioners raised concerns
                about whether the 2015 Rule violated the Constitution and the CWA and
                whether its promulgation violated the APA and other statutes.
                Environmental petitioners also challenged the 2015 Rule, claiming in
                part that the 2015 Rule was too narrow because of the distance
                limitations and other issues. On October 9, 2015, approximately six
                weeks after the 2015 Rule took effect in the 37 States, the District of
                Columbia, and U.S.
                [[Page 22259]]
                Territories that were not subject to the preliminary injunction issued
                by the District of North Dakota, the Sixth Circuit stayed the 2015 Rule
                nationwide after concluding, among other things, that State petitioners
                had demonstrated ``a substantial possibility of success on the merits
                of their claims.'' In re EPA & Dep't of Def. Final Rule, 803 F.3d 804,
                807 (6th Cir. 2015) (``In re EPA'').
                 On January 13, 2017, the U.S. Supreme Court granted certiorari on
                the question of whether the courts of appeals have original
                jurisdiction to review challenges to the 2015 Rule. See Nat'l Ass'n of
                Mfrs. v. Dep't of Def., 137 S. Ct. 811 (2017). The Sixth Circuit
                granted petitioners' motion to hold in abeyance the briefing schedule
                in the litigation challenging the 2015 Rule pending a Supreme Court
                decision on the question of the court of appeals' jurisdiction. On
                January 22, 2018, the Supreme Court, in a unanimous opinion, held that
                the 2015 Rule is subject to direct review in the district courts. Nat'l
                Ass'n of Mfrs. v. Dep't of Def., 138 S. Ct. 617, 624 (2018). Throughout
                the pendency of the Supreme Court litigation (and for a short time
                thereafter), the Sixth Circuit's nationwide stay remained in effect. In
                response to the Supreme Court's decision, on February 28, 2018, the
                Sixth Circuit lifted the stay and dismissed the corresponding petitions
                for review. See In re Dep't of Def. & EPA Final Rule, 713 Fed. Appx.
                489 (6th Cir. 2018).
                 Following the Supreme Court's jurisdictional ruling, district court
                litigation regarding the 2015 Rule resumed. At this time, the 2015 Rule
                continues to be subject to a preliminary injunction issued by the
                District of North Dakota as to 12 States: Alaska, Arizona, Arkansas,
                Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, North Dakota, South
                Dakota, and Wyoming.\19\ The 2015 Rule also is subject to a preliminary
                injunction issued by the U.S. District Court for the Southern District
                of Georgia as to 11 more States: Georgia, Alabama, Florida, Indiana,
                Kansas, Kentucky, North Carolina, South Carolina, Utah, West Virginia,
                and Wisconsin. Georgia v. Pruitt, 326 F. Supp. 3d 1356, 1364 (S.D. Ga.
                2018). The Southern District of Georgia subsequently issued an order
                remanding the 2015 Rule to the agencies, finding that the 2015 Rule
                exceeded the agencies' statutory authority under the CWA and was
                promulgated in violation of the APA. Georgia v. Wheeler, No. 2:15-cv-
                079, 2019 WL 3949922 (S.D. Ga. Aug. 21, 2019). ``[I]n light of the
                serious defects identified,'' the court retained its injunction against
                the 2015 Rule. Id. at *36.\20\
                ---------------------------------------------------------------------------
                 \19\ As of the date this final rule was signed, the
                applicability and scope of the North Dakota district court's
                preliminary injunction in New Mexico is unclear. See supra note 18.
                 \20\ The Southern District of Georgia later denied as moot
                plaintiffs' motions for reconsideration asking the court to vacate,
                rather than remand, the 2015 Rule. Order, Georgia v. Wheeler, No.
                2:15-cv-079 (S.D. Ga. Jan. 3, 2020).
                ---------------------------------------------------------------------------
                 In September 2018, the U.S. District Court for the Southern
                District of Texas issued a preliminary injunction against the 2015 Rule
                in response to motions filed by the States of Texas, Louisiana, and
                Mississippi and several business associations, finding that enjoining
                the rule would provide ``much needed governmental, administrative, and
                economic stability'' while the rule undergoes judicial review. See
                Texas v. EPA, No. 3:15-cv-162, 2018 WL 4518230, at *1 (S.D. Tex. Sept.
                12, 2018). The court observed that if it did not temporarily enjoin the
                rule, ``it risks asking the states, their governmental subdivisions,
                and their citizens to expend valuable resources and time
                operationalizing a rule that may not survive judicial review.'' Id. In
                May 2019, the court remanded the 2015 Rule to the agencies on the
                grounds that the rule violated the APA. Specifically, the court found
                that the rule violated the APA's notice and comment requirements
                because: (1) The 2015 Rule's definition of ``adjacent'' waters (which
                relied on distance-based limitations) was not a ``logical outgrowth''
                of the proposal's definition of ``adjacent'' waters (which relied on
                ecologic and hydrologic criteria); and (2) the agencies denied
                interested parties an opportunity to comment on the final version of
                the Connectivity Report, which served as the technical basis for the
                final rule. See Texas v. EPA, 389 F. Supp. 3d 497 (S.D. Tex. 2019).\21\
                ---------------------------------------------------------------------------
                 \21\ The Southern District of Texas later denied plaintiffs'
                motions for reconsideration urging the court to vacate, rather than
                remand, the 2015 Rule. Order, Texas v. EPA, No. 3:15-cv-00162 (S.D.
                Tex. Nov. 6, 2019).
                ---------------------------------------------------------------------------
                 In July 2019, the U.S. District Court for the District of Oregon
                issued a preliminary injunction against the 2015 Rule in the State of
                Oregon. Order, Or. Cattlemen's Ass'n v. EPA, No. 19-00564 (D. Or. July
                26, 2019). As a result, the 2015 Rule was enjoined in more than half of
                the States.
                 Three additional States (Ohio, Michigan, and Tennessee) sought a
                preliminary injunction against the 2015 Rule in the U.S. District Court
                for the Southern District of Ohio. In March 2019, the court denied the
                States' motion, finding that the States had ``failed to demonstrate
                that they will suffer imminent and irreparable harm absent an
                injunction.'' See Ohio v. EPA, No. 2:15-cv-02467, 2019 WL 1368850 (S.D.
                Ohio Mar. 26, 2019). The court subsequently denied the States' motion
                for reconsideration of its order denying the preliminary injunction
                motion, and the States have since filed an appeal of the court's order
                in the Sixth Circuit. See Ohio v. EPA, No. 2:15-cv-02467, 2019 WL
                1958650 (S.D. Ohio May 2, 2019); Plaintiffs' Notice of Appeal, Ohio v.
                EPA, No. 2:15-cv-02467 (S.D. Ohio May 28, 2019).\22\
                ---------------------------------------------------------------------------
                 \22\ Parties challenging the 2015 Rule in the U.S. District
                Court for the Northern District of Oklahoma, including the State of
                Oklahoma and the U.S. Chamber of Commerce, unsuccessfully sought a
                motion for a preliminary injunction against the 2015 Rule and later
                stipulated to a voluntary dismissal of the case. See Opinion &
                Order, Oklahoma v. EPA, No. 4:15-cv-00381 (N.D. Okla. May 29, 2019);
                Stipulation of Voluntary Dismissal, Oklahoma v. EPA, No. 4:15-cv-
                00381 (N.D. Okla. Jan. 7, 2019). Following the effective date of the
                2019 Rule, an additional motion for a preliminary injunction against
                the 2015 Rule was denied as moot in the U.S. District Court for the
                Western District of Washington. Order, Wash. Cattlemen's Ass'n v.
                EPA, No. 19-00569 (W.D. Wash. Dec. 30, 2019).
                ---------------------------------------------------------------------------
                C. Executive Order 13778 and the ``Step One'' Rulemaking
                 On February 28, 2017, the President issued Executive Order 13778
                entitled ``Restoring the Rule of Law, Federalism, and Economic Growth
                by Reviewing the `Waters of the United States' Rule.'' Section 1 of the
                Executive Order states, ``[i]t is in the national interest to ensure
                that the Nation's navigable waters are kept free from pollution, while
                at the same time promoting economic growth, minimizing regulatory
                uncertainty, and showing due regard for the roles of the Congress and
                the States under the Constitution.'' The Executive Order directs the
                EPA and the Army to review the 2015 Rule for consistency with the
                policy outlined in Section 1 of the Order and to issue a proposed rule
                rescinding or revising the 2015 Rule as appropriate and consistent with
                law (Section 2). The Executive Order also directs the agencies to
                ``consider interpreting the term `navigable waters' . . . in a manner
                consistent with'' Justice Scalia's plurality opinion in Rapanos v.
                United States, 547 U.S. 715 (2006) (Section 3).
                 On March 6, 2017, the agencies published a notice of intent to
                review the 2015 Rule and provide notice of a forthcoming proposed
                rulemaking consistent with the Executive Order. 82 FR 12532. Shortly
                thereafter, the agencies announced that they would implement the
                Executive Order in a two-step approach. On July 27, 2017,
                [[Page 22260]]
                the agencies published the ``Definition of `Waters of the United
                States'--Recodification of Pre-Existing Rules'' notice of proposed
                rulemaking (NPRM) (82 FR 34899) that proposed to repeal the 2015 Rule
                and recodify the regulatory text that governed prior to the
                promulgation of the 2015 Rule, consistent with Supreme Court decisions
                and informed by applicable guidance documents and longstanding agency
                practice. The agencies refer to this as the ``Step One'' rule. The
                agencies invited comment on the NPRM over a 62-day period. On July 12,
                2018, the agencies published a supplemental notice of proposed
                rulemaking (SNPRM) to clarify, supplement, and seek additional comment
                on the proposed repeal and recodification. 83 FR 32227. The agencies
                invited comment on the SNPRM over a 30-day period.
                 On October 22, 2019, the agencies published a final rule repealing
                the 2015 Rule and recodifying the pre-existing regulations as an
                interim matter until this final rule becomes effective. 84 FR 56626. In
                developing the final Step One rule (referred to as the ``2019 Rule''),
                the agencies reviewed approximately 690,000 public comments received on
                the NPRM and approximately 80,000 comments received on the SNPRM from a
                broad spectrum of interested parties. In the NPRM and SNPRM the
                agencies sought comment on all aspects of the NPRM, the economic
                analysis for the NPRM, and the SNPRM, including the repeal of the 2015
                Rule, the recodification of the prior regulations, the considerations
                underlying the proposal and agencies' reasons for the proposal, and the
                agencies' proposed conclusions that the 2015 Rule exceeded the
                agencies' authority under the CWA.
                 The agencies finalized the 2019 Rule, which became effective
                December 23, 2019, and repealed the 2015 Rule for four primary reasons.
                First, the agencies concluded that the 2015 Rule did not implement the
                legal limits on the scope of the agencies' authority under the CWA as
                intended by Congress and reflected in Supreme Court cases, including
                Justice Kennedy's articulation of the significant nexus test in
                Rapanos. Second, the agencies concluded that in promulgating the 2015
                Rule the agencies failed to adequately consider and accord due weight
                to the policy of the Congress in CWA section 101(b) to ``recognize,
                preserve, and protect the primary responsibilities and rights of States
                to prevent, reduce, and eliminate pollution'' and ``to plan the
                development and use . . . of land and water resources.'' 33 U.S.C.
                1251(b). Third, the agencies repealed the 2015 Rule to avoid
                interpretations of the CWA that push the envelope of their
                constitutional and statutory authority absent a clear statement from
                Congress authorizing the encroachment of federal jurisdiction over
                traditional State land-use planning authority. Lastly, the agencies
                concluded that the 2015 Rule's distance-based limitations suffered from
                certain procedural errors and a lack of adequate record support. The
                agencies found that these reasons, collectively and individually,
                warranted repealing the 2015 Rule.
                 At this time, the regulations defining the scope of federal CWA
                jurisdiction are those portions of the CFR as they existed before the
                amendments promulgated in the 2015 Rule. The agencies concluded that it
                was appropriate as an interim matter to restore the pre-existing
                regulations to provide regulatory certainty as the agencies considered
                the proposed revised definition of ``waters of the United States'' and
                because, as implemented, those prior regulations adhere more closely
                than the 2015 Rule to the jurisdictional limits reflected in the
                statute and case law. As anticipated in the 2019 Rule, this final rule
                replaces the recodified pre-2015 regulations, upon its effective date.
                 As of the time of signature of this final rule, challenges to the
                agencies' 2019 Rule are pending in six district courts, wherein both
                environmental and industry groups have either filed new complaints or
                sought to supplement existing complaints to challenge the rule in whole
                or in part. See New York v. Wheeler, No. 19-11673 (S.D.N.Y., complaint
                filed Dec. 20, 2019); Wash. Cattlemen's Ass'n v. EPA, No. 2:19-cv-00569
                (W.D. Wash., supplemental amended complaint filed Dec. 20, 2019);
                Murray v. Wheeler, No. 1:19-cv-01498 (N.D.N.Y., complaint filed Dec. 4,
                2019); S.C. Coastal Conservation League v. Wheeler, No. 2:19-cv-3006
                (D.S.C., complaint filed Oct. 23, 2019); N.M. Cattle Growers' Ass'n v.
                EPA, No. 1:19-cv-988 (D.N.M., complaint filed Oct. 22, 2019); Pierce v.
                EPA, No. 0:19-cv-2193 (D. Minn., supplemental complaint filed Oct. 22,
                2019).
                D. Summary of Stakeholder Outreach and the ``Step Two'' Rulemaking
                 Following the March 6, 2017 Federal Register notice announcing the
                agencies' intent to review and rescind or revise the 2015 Rule, the
                agencies initiated an effort to engage the public to hear perspectives
                as to how the agencies could define ``waters of the United States,''
                including creating a new website to provide information on the
                rulemaking. See www.epa.gov/wotus-rule. On April 19, 2017, the agencies
                held an initial Federalism consultation meeting with State and local
                government officials as well as national organizations representing
                such officials. The agencies also convened several additional meetings
                with intergovernmental associations and their members to solicit input
                on the future rule. The EPA, with participation from the Army,
                initiated Tribal consultation on April 20, 2017, under the EPA Policy
                on Consultation and Coordination with Indian Tribes. See Section VI for
                further details on the agencies' consultations. The agencies considered
                comments received from federalism and tribal consultations as they
                developed this final rule.
                 In addition to engaging State, tribal, and local officials through
                federalism and tribal consultations, the agencies sought feedback on
                the definition of ``waters of the United States'' from a broad audience
                of stakeholders, including small entities (small businesses, small
                organizations, and small government jurisdictions), through a series of
                outreach webinars that were held September 9, 2017, through November
                21, 2017, and through an in-person meeting for small entities on
                October 23, 2017. A summary of these public listening sessions is
                available in the docket (Docket Id. No. EPA-HQ-OW-2018-0149-0091) for
                this rule. The webinars were tailored to specific sectors, including
                agriculture (row crop, livestock, silviculture); conservation (hunters
                and anglers); small entities (small businesses, small organizations,
                small government jurisdictions); construction and transportation;
                environment and public advocacy (including health and environmental
                justice); mining; energy and chemical industry; scientific
                organizations and academia; stormwater, wastewater management, and
                drinking water agencies; and the general public.
                 At the pre-proposal webinars and meetings with stakeholders, the
                agencies provided a presentation and sought input on specific issues,
                such as potential approaches to defining the phrases ``relatively
                permanent'' waters and ``continuous surface connections'' as
                articulated by the plurality opinion in Rapanos, as well as other
                considerations addressing specific geomorphological features,
                exclusions and exemptions, costs and benefits, and aquatic resource
                data that the agencies might consider in the technical analyses for a
                future rule. As part of this outreach effort, the agencies established
                a public recommendations docket (Docket ID No. EPA-HQ-OW-2017-0480)
                that opened
                [[Page 22261]]
                August 28, 2017, and closed November 28, 2017. Participant comments and
                letters submitted represent a diverse range of interests, positions,
                suggestions, and recommendations provided to the agencies. The agencies
                received over 6,300 recommendations (available on Regulations.gov at
                https://www.regulations.gov/docket?D=EPA-HQ-OW-2017-0480) that were
                considered as the agencies developed the proposed revised definition of
                ``waters of the United States.'' The agencies also considered
                recommendations as to how the agencies should define ``waters of the
                United States'' that were submitted in public comments on the agencies'
                proposed ``Step One'' rule (82 FR 34899, July 27, 2017) and the July
                2018 SNPRM (83 FR 32227, July 12, 2018).
                 The agencies continued their pre-proposal engagement with States
                and Tribes via additional webinars and in-person meetings. On March 8
                and 9, 2018, the agencies held an in-person State Co-Regulators
                Workshop with representatives from nine States (Arizona, Arkansas,
                Florida, Iowa, Maryland, Minnesota, Oregon, Pennsylvania, and Wyoming)
                and convened a subsequent in-person meeting on March 22, 2018, with
                representatives from all States at the spring meeting of the
                Environmental Council of the States. The agencies also held an in-
                person Tribal Co-Regulators Workshop on March 6 and 7, 2018, with
                representatives from 20 tribes. These meetings were intended to seek
                technical input as the agencies developed the proposed rule. The
                agencies also sought pre-proposal input from Tribes through national
                and regional tribal meetings, including through listening sessions at
                the Tribal Land and Environment Forum (August 16, 2017 and August 15,
                2018) and the National Congress of American Indians Annual Convention
                (October 24, 2018).
                 On December 12, 2018, the agencies signed the proposed rule to
                revise the definition of ``waters of the United States,'' as the second
                step of the comprehensive two-step process consistent with Executive
                Order 13778. The proposal was published on February 14, 2019. 84 FR
                4154. The agencies proposed to interpret the term ``waters of the
                United States'' to encompass: Traditional navigable waters, including
                the territorial seas; tributaries that contribute perennial or
                intermittent flow to such waters; certain ditches; certain lakes and
                ponds; impoundments of otherwise jurisdictional waters; and wetlands
                adjacent to other jurisdictional waters. The 60-day public comment
                period for the proposed revised definition of ``waters of the United
                States'' (``Step Two'' Rule) closed on April 15, 2019.\23\
                ---------------------------------------------------------------------------
                 \23\ The pre-publication of the proposed rule was published on
                EPA's website on December 12, 2018, approximately 60 days prior to
                its publication in the Federal Register and the date the formal
                public comment period began.
                ---------------------------------------------------------------------------
                 The agencies conducted a variety of stakeholder outreach on the
                proposed rule upon its publication in the Federal Register. On February
                14, 2019, the agencies held a public webcast to present key elements of
                the proposed rule (see https://www.youtube.com/watch?v=ZZ6kFJasDhg&feature=youtu.be), and held a public hearing in
                Kansas City, Kansas, on February 27 and 28, 2019, to hear feedback from
                individuals from regulated industry sectors, environmental and
                conservation organizations, State agencies, tribal governments, and
                private citizens. The agencies also continued engagement with States
                and Tribes through a series of in-person meetings with State and tribal
                representatives in Kansas City, Kansas; Atlanta, Georgia; Albuquerque,
                New Mexico; and Seattle, Washington during the public comment period
                for the proposed rule. During these meetings, the agencies provided an
                overview of the proposed rule, responded to clarifying questions from
                participants, discussed implementation considerations, and heard
                feedback on the agencies' interest in developing geospatial datasets of
                jurisdictional waters. A transcript of the public hearing and related
                materials and summaries of the State and tribal meetings can be found
                in the docket for the final rule. At the request of individual Tribes,
                the agencies also continued to hold staff-level and leader-to-leader
                meetings with individual Tribes.
                 In developing this final rule, the agencies reviewed and considered
                approximately 620,000 comments received on the proposed rule from a
                broad spectrum of interested parties. Commenters provided a wide range
                of feedback on the various aspects of the proposal, including the legal
                basis for the proposed rule, the agencies' proposed treatment of
                categories of jurisdictional waters and those features that would not
                be jurisdictional, the economic analysis and resource and programmatic
                assessment for the proposed rule, and the agencies' considerations for
                developing geospatial datasets of jurisdictional waters in partnership
                with other federal agencies, States, and Tribes. The agencies discuss
                comments received and their responses in the applicable sections of
                this final rule. A complete response to comments document is available
                in the docket for this final rule at Docket ID No. EPA-HQ-OW-2018-0149.
                 The agencies also engaged with the EPA's Science Advisory Board
                (SAB) during the development of the rule on several occasions. The
                agencies met with the SAB prior to the proposed rule and following
                publication of the proposed rule to explain the basis for the rule and
                to address the SAB's questions and initial observations. The SAB issued
                a draft commentary on the proposed rule on December 31, 2019, and held
                a public meeting on the matter on January 17, 2020. The SAB's draft
                commentary asserted that the proposed rule did not fully incorporate
                the Connectivity Report and offers no comparable body of peer reviewed
                evidence to support this departure. As the agencies made clear in the
                proposed rule preamble and explain in greater detail in this notice,
                the agencies used the Connectivity Report to inform certain aspects of
                the definition of ``waters of the United States,'' but recognize that
                science cannot dictate where to draw the line between Federal and State
                waters, as this is a legal question that must be answered based on the
                overall framework and construct of the CWA. The SAB's draft also
                addresses the absence of ``ground water protection;'' the exclusion of
                ``irrigation canals'' from regulatory jurisdiction; the exclusion of
                ``adjacent wetlands that do not abut or have a direct hydrologic
                surface connection to otherwise jurisdictional waters;'' and the
                absence of ``long term clarity'' as a result of the asserted lack of
                scientific basis for the proposed rule.
                 The relevant comments raised by the SAB were also raised by public
                commenters throughout the rulemaking process, and as a result, have
                been addressed by the agencies in the final rule, supporting documents,
                and throughout this notice. In brief, however, the agencies note that
                the final rule is consistent with the agencies' longstanding position
                that ``waters of the United States'' do not include groundwater; that
                the agencies do not use the term ``irrigation canals'' in the final
                rule; that ``irrigation ditches'' constructed in uplands and
                ``irrigation return flows'' generally have been not been subject to CWA
                regulatory requirements; and that the agencies have expanded
                jurisdiction over certain ``adjacent wetlands'' compared to the
                proposal to better incorporate common principles from the Rapanos
                plurality and concurring opinions, that the final rule strikes a better
                balance between the objective and policy in CWA sections 101(a) and
                101(b), respectively; and that
                [[Page 22262]]
                the final rule is consistent with the text, structure, legislative
                history, and applicable Supreme Court guidance. A memorandum
                summarizing the agencies' interactions with the SAB and the SAB's draft
                commentary are available in the docket for this final rule.
                E. Overview of Legal Construct for the Final Rule
                 As the preceding summary of the statutory and regulatory history
                makes clear, the central term delineating the federal geographic scope
                of authority under the CWA--``waters of the United States''--has been
                the subject of debate and litigation for many years. The agencies are
                promulgating a regulation to define ``waters of the United States''
                adhering to Constitutional and statutory limitations, the policies and
                objective of the CWA, and case law. The revised definition will allow
                the regulatory agencies and the regulated community to protect
                navigable waters from pollution while providing an implementable
                approach to determining regulatory jurisdiction under the CWA. This
                subsection summarizes the legal principles that inform the agencies'
                final rule, and the following section (Section III) describes how the
                agencies are applying those legal principles to support the final
                revised definition of ``waters of the United States.''
                1. Statutory Framework
                 To determine the scope of executive branch authority under the CWA,
                the agencies begin with the text of the statute. The objective of the
                CWA, as established by Congress, is ``to restore and maintain the
                chemical, physical, and biological integrity of the Nation's waters.''
                33 U.S.C. 1251(a). As discussed in Section II.B, in order to meet that
                objective, Congress declared two national water quality goals and
                established several key policies that direct the work of the agencies.
                Congress also envisioned a major role for the States in implementing
                the CWA, carefully balancing the traditional power of States to
                regulate land and water resources within their borders with the need
                for national water quality regulation.
                 The agencies have developed regulatory and non-regulatory programs
                designed to ensure that the full statute is implemented as Congress
                intended. See, e.g., Hibbs v. Winn, 542 U.S. 88, 101 (2004) (``A
                statute should be construed so that effect is given to all its
                provisions, so that no part will be inoperative or superfluous, void or
                insignificant.''). This includes pursuing the overall ``objective'' of
                the CWA to ``restore and maintain the chemical, physical, and
                biological integrity of the Nation's waters,'' 33 U.S.C. 1251(a), while
                implementing the specific ``policy'' directives from Congress to, among
                other things, ``recognize, preserve, and protect the primary
                responsibilities and rights of States to prevent, reduce, and eliminate
                pollution'' and ``to plan the development and use . . . of land and
                water resources.'' Id. at 1251(b); see also Webster's II, New Riverside
                University Dictionary (1994) (defining ``policy'' as a ``plan or course
                of action, as of a government[,] designed to influence and determine
                decisions and actions;'' an ``objective'' is ``something worked toward
                or aspired to: Goal'').\24\ The agencies therefore recognize a
                distinction between the specific word choices of Congress, including
                the need to develop regulatory and non-regulatory programs that aim to
                accomplish the goals of the Act while implementing the specific policy
                directives of Congress.\25\ To do so, the agencies must determine what
                Congress had in mind when it defined ``navigable waters'' in 1972 as
                ``the waters of the United States.''
                ---------------------------------------------------------------------------
                 \24\ The legislative history of the CWA further illuminates the
                distinction between the terms ``policy'' and ``objective,'' or
                ``goal.'' As Congress drafted the 1972 CWA amendments, the Senate
                bill set the ``no-discharge of pollutants into the navigable water
                by 1985'' provision as a policy whereas the House bill set it as a
                goal. The Act was ultimately passed with the ``no-discharge by
                1985'' provision established as a goal. See 33 U.S.C 1251(a)(1).
                During the House's consideration of the Conference Report,
                Representative Robert E. Jones, Jr. captured the policy versus goal
                distinction in section 101(a)(1) as follows: ``The objective of this
                legislation is to restore and preserve for the future the integrity
                of our Nation's waters. The bill sets forth as a national goal the
                complete elimination of all discharges into our navigable waters by
                1985, but . . . the conference report states clearly that achieving
                the 1985 target date is a goal, not a national policy. As such, it
                serves as a focal point for long-range planning, and for research
                and development in water pollution control technology . . . . While
                it is our hope that we can succeed in eliminating all discharge into
                our waters by 1985, without unreasonable impact on the national
                life, we recognized in this report that too many imponderables
                exist, some still beyond our horizons, to prescribe this goal today
                as a legal requirement.'' 118 Cong. Rec. H. 33749 (daily ed. October
                4, 1972).
                 \25\ See, e.g., Nat'l Fed'n of Indep. Bus. v. Sebelius, 567 U.S.
                519, 544 (2012) (``Where Congress uses certain language in one part
                of a statute and different language in another, it is generally
                presumed that Congress acts intentionally.''); Russello v. United
                States, 464 U.S. 16, 23 (1983) (``[Where] Congress includes
                particular language in one section of a statute but omits it in
                another section of the same Act, it is generally presumed that
                Congress acts intentionally and purposely in the disparate inclusion
                or exclusion.'')
                ---------------------------------------------------------------------------
                 Congress' authority to regulate navigable waters under the CWA
                derives from its power to regulate the ``channels of interstate
                commerce'' under the Commerce Clause. Gibbons v. Ogden, 22 U.S. (9
                Wheat.) 1 (1824). In United States v. Lopez, the Supreme Court
                explained that the Commerce Clause gives Congress the authority to
                regulate in three areas: The ``channels of interstate commerce,'' the
                ``instrumentalities of interstate commerce,'' and those additional
                activities having ``a substantial relation to interstate commerce.''
                514 U.S. 549, 558-59 (1995). Some commenters stated that Congress'
                authority over ``waters of the United States'' is not tethered to
                navigable channels of interstate commerce, but is also derived from its
                authority over the ``instrumentalities of interstate commerce'' and
                activities that ``substantially affect'' interstate commerce. See id.
                The agencies disagree with these comments. The Supreme Court made clear
                in SWANCC that the term ``navigable'' indicates ``what Congress had in
                mind as its authority for enacting the CWA: Its traditional
                jurisdiction over waters that were or had been navigable in fact or
                which could reasonably be so made.'' 531 U.S. 159, 172 (2001). The
                Court further explained that nothing in the legislative history of the
                Act provides any indication that ``Congress intended to exert anything
                more than its commerce power over navigation.'' Id. at 168 n.3. The
                Supreme Court, however, has recognized that Congress intended ``to
                exercise its powers under the Commerce clause to regulate at least some
                waters that would not be deemed `navigable' under the classical
                understanding of that term.'' Riverside Bayview, 474 U.S. at 133; see
                also SWANCC, 531 U.S. at 167.
                 The classical understanding of the term ``navigable'' was first
                articulated by the Supreme Court in The Daniel Ball:
                 Those rivers must be regarded as public navigable rivers in law
                which are navigable in fact. And they are navigable in fact when
                they are used, or are susceptible of being used, in their ordinary
                condition, as highways of commerce, over which trade and travel are
                or may be conducted in the customary modes of trade and travel on
                water. And they constitute navigable waters of the United States
                within the meaning of the acts of Congress, in contradistinction
                from the navigable waters of the States, when they form in their
                ordinary condition by themselves, or by uniting with other waters, a
                continued highway over which commerce is or may be carried on with
                other States or foreign countries in the customary modes in which
                such commerce is conducted by water.
                77 U.S. (10 Wall.) 557, 563 (1871). Subsequently, this traditional test
                was expanded to include waters that had been used in the past for
                interstate commerce, see Economy Light & Power Co. v. United States,
                256 U.S. 113, 123 (1921), and waters that are susceptible
                [[Page 22263]]
                for use with reasonable improvement, see United States v. Appalachian
                Elec. Power Co., 311 U.S. 377, 407-10 (1940).
                 By the time the 1972 CWA amendments were enacted, the Supreme Court
                had held that Congress' authority over the channels of interstate
                commerce was not limited to regulation of the channels themselves but
                could extend to activities necessary to protect the channels. See
                Oklahoma ex rel. Phillips v. Guy F. Atkinson Co., 313 U.S. 508, 523
                (1941) (``Congress may exercise its control over the non-navigable
                stretches of a river in order to preserve or promote commerce on the
                navigable portions.''). The Supreme Court had also clarified that
                Congress could regulate waterways that formed a part of a channel of
                interstate commerce, even if they are not themselves navigable or do
                not cross state boundaries. See Utah v. United States, 403 U.S. 9, 11
                (1971).
                 These developments were discussed during the legislative process
                leading up to the passage of the 1972 CWA amendments, and certain
                members referred to the scope of the amendments as encompassing
                waterways that serve as a ``link in the chain'' of interstate commerce
                as it flows through various channels of transportation, such as
                railroads and highways. See, e.g., 118 Cong. Rec. 33756-57 (1972)
                (statement of Rep. Dingell); 118 Cong. Rec. 33699 (Oct. 4, 1972)
                (statement of Sen. Muskie).\26\ Other references suggest that
                congressional committees at least contemplated applying the ``control
                requirements'' of the Act ``to the navigable waters, portions thereof,
                and their tributaries.'' S. Rep. No. 92-414, at 77 (1971). Some
                commenters on this rulemaking stated that Congress' authority under the
                CWA is limited to waters that actually transport commerce, not their
                tributaries or adjacent wetlands, and that this limitation on CWA
                jurisdiction would fully preserve the authority of States to address
                pollution. The agencies disagree with these commenters based on the
                Supreme Court's holdings and the legislative history of the 1972
                amendments discussed above, as well as the text of the 1977 amendments
                to the CWA. Specifically, in 1977, when Congress authorized State
                assumption over the section 404 dredged or fill material permitting
                program, Congress limited the scope of waters that could be assumed by
                a State or Tribe by requiring the Corps to retain permitting authority
                over RHA waters (as identified by the test outlined in The Daniel Ball)
                plus wetlands adjacent to those waters, minus historic-use-only waters.
                See 33 U.S.C. 1344(g)(1).\27\ This suggests that Congress had in mind a
                broader scope of waters subject to CWA jurisdiction than waters
                traditionally understood as navigable. See SWANCC, 531 U.S. at 171;
                Riverside Bayview, 474 U.S. at 138 n.11. Thus, Congress intended to
                assert federal authority over more than just waters traditionally
                understood as navigable, and Congress rooted that authority in ``its
                commerce power over navigation.'' SWANCC, 531 U.S. at 168 n.3. However,
                there must be a limit to that authority and to what water is subject to
                federal jurisdiction. How the agencies should exercise that authority
                has been the subject of dispute for decades, but the Supreme Court on
                three occasions has analyzed the issue and provided some instructional
                guidance for the agencies to consider in developing this final rule.
                ---------------------------------------------------------------------------
                 \26\ The agencies recognize that individual member statements
                are not a substitute for full congressional intent, but they do help
                provide context for issues that were discussed during the
                legislative debates. For a detailed discussion of the legislative
                history of the 1972 CWA amendments, see Albrecht & Nickelsburg,
                Could SWANCC Be Right? A New Look at the Legislative History of the
                Clean Water Act, 32 ELR 11042 (Sept. 2002).
                 \27\ For a detailed discussion of the legislative history
                supporting the enactment of CWA section 404(g), see Final Report of
                the Assumable Waters Subcommittee (May 2017), App. F., available at
                https://www.epa.gov/sites/production/files/2017-06/documents/awsubcommitteefinalreprort_05-2017_tag508_05312017_508.pdf https://www.epa.gov/sites/production/files/2017-06/documents/awsubcommitteefinalreprort_05-2017_tag508_05312017_508.pdf.
                ---------------------------------------------------------------------------
                2. U.S. Supreme Court Precedent
                a. Adjacent Wetlands
                 In Riverside Bayview, the Supreme Court considered the Corps'
                assertion of jurisdiction over ``low-lying, marshy land'' immediately
                abutting a water traditionally understood as navigable on the grounds
                that it was an ``adjacent wetland'' within the meaning of the Corps'
                then-existing regulations. 474 U.S. at 124. The Court addressed the
                question of whether non-navigable wetlands may be regulated as waters
                of the United States on the basis that they are ``adjacent to''
                navigable-in-fact waters and ``inseparably bound up with'' them because
                of their ``significant effects on water quality and the aquatic
                ecosystem.'' See id. at 131-35 & n.9.
                 In determining whether to give deference to the Corps' assertion of
                jurisdiction over adjacent wetlands, the Court acknowledged the
                difficulty in determining where federal jurisdiction ends, noting that
                the line is somewhere between open water and dry land:
                 In determining the limits of its power to regulate discharges
                under the Act, the Corps must necessarily choose some point at which
                water ends and land begins. Our common experience tells us that this
                is often no easy task: The transition from water to solid ground is
                not necessarily or even typically an abrupt one. Rather, between
                open waters and dry land may lie shallows, marshes, mudflats,
                swamps, bogs--in short, a huge array of areas that are not wholly
                aquatic but nevertheless fall far short of being dry land. Where on
                this continuum to find the limit of ``waters'' is far from obvious.
                Id. at 132 (emphasis added). Within this statement, the Supreme Court
                identifies a basic principle for adjacent wetlands: The limits of
                jurisdiction lie within the ``continuum'' or ``transition'' ``between
                open waters and dry land.'' Observing that Congress intended the CWA
                ``to regulate at least some waters that would not be deemed
                `navigable,' '' the Court held that it is ``a permissible
                interpretation of the Act'' to conclude that ``a wetland that actually
                abuts on a navigable waterway'' falls within the ``definition of
                `waters of the United States.' '' Id. at 133, 135. Thus, a wetland that
                abuts a water traditionally understood as navigable is subject to CWA
                jurisdiction because it is ``inseparably bound up with the `waters' of
                the United States.'' Id. at 134. ``This holds true even for wetlands
                that are not the result of flooding or permeation by water having its
                source in adjacent bodies of open water.'' Id.
                 The Supreme Court also noted that the agencies can establish
                categories of jurisdiction for adjacent wetlands. See id. at 135 n.9.
                It made clear that these categories could be reasonable if the Corps
                concludes that ``in the majority of cases, adjacent wetlands have
                significant effects on water quality and the aquatic ecosystem.'' Id. A
                definition of ``waters of the United States'' ``can stand'' even if it
                potentially sweeps in individual wetlands that are not sufficiently
                ``intertwined with the ecosystem of adjacent waterways'' to warrant
                protection. Id. In such cases, if the regulating entity determines that
                a particular wetland lacks importance to the aquatic environment, or
                its importance is outweighed by other factors, that wetland could be
                developed through the permit issuance process. Id.
                 Some commenters noted that the definition of ``adjacent wetlands''
                that the Supreme Court unanimously upheld in Riverside Bayview included
                categories of wetlands that would not be per se ``adjacent'' under the
                proposed rule, including all ``[w]etlands separated from other waters
                of the United States by man-made dikes or barriers, natural river
                berms, beach dunes and the like.'' 51 FR 41251 (Nov. 13, 1986). These
                commenters stated that the Court deferred to the Corps' judgment that
                [[Page 22264]]
                wetlands may affect the water quality of jurisdictional waterbodies
                even if the waterbodies do not inundate the wetlands. See Riverside
                Bayview, 474 U.S. at 133-35. The proposed rule included wetlands as
                jurisdictional absent inundation by another water. See e.g., 84 FR 4187
                (``The proposed definition of `adjacent wetlands' would not require
                surface water exchange between wetlands and the jurisdictional waters
                they abut to create the jurisdictional link[.]''). As explained in
                Section III.G., the agencies have considered public comments in light
                of the statutory text and other relevant considerations and are
                finalizing a definition of ``adjacent wetlands'' that is more
                encompassing than the proposal. In any event, the agencies note that a
                Court's deference to an agency's particular interpretation of a statute
                does not foreclose alternative interpretations. The Supreme Court has
                held that ``a court's choice of one reasonable reading of an ambiguous
                statute does not preclude an implementing agency from later adopting a
                different reasonable interpretation.'' United States v. Eurodif S.A.,
                555 U.S. 305, 315 (2009). This principle follows from Chevron, U.S.A.,
                Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984),
                which ``established a `presumption that Congress, when it left
                ambiguity in a statute meant for implementation by an agency,
                understood that the ambiguity would be resolved, first and foremost, by
                the agency, and desired the agency (rather than the courts) to possess
                whatever degree of discretion the ambiguity allows.' '' Nat'l Cable &
                Telecommunications Ass'n v. Brand X Internet Servs., 545 U.S. 967, 982
                (2005) (quoting Smiley v. Citibank, 517 U.S. 735, 740-41 (1996)).
                Moreover, an ``initial agency interpretation is not instantly carved in
                stone.'' Chevron, 467 U.S. at 863; see also Encino Motorcars, LLC v.
                Navarro, 136 S. Ct. 2117, 2125 (2016) (``[A]gencies are free to change
                their existing policies as long as they provide a reasoned explanation
                for the change.'') (citations omitted). Consistent with the APA and
                applicable case law, in this final rule the agencies have provided
                ample justification for a change in interpretation of the CWA
                concerning the scope of jurisdiction over waters and wetlands,
                including any changes from their prior interpretations.
                 The Supreme Court in Riverside Bayview declined to decide whether
                wetlands that are not adjacent to navigable waters could also be
                regulated by the agencies. See 474 U.S. at 124 n.2 and 131 n.8. In
                SWANCC a few years later, however, the Supreme Court analyzed a similar
                question in the context of an abandoned sand and gravel pit located
                some distance from a traditional navigable water, with excavation
                trenches that ponded--some only seasonally--and served as habitat for
                migratory birds. 531 U.S. at 162-63. The Supreme Court rejected the
                government's stated rationale for asserting jurisdiction over such
                ``nonnavigable, isolated, intrastate waters'' as outside the scope of
                CWA jurisdiction. Id. at 171-72. In doing so, the Supreme Court noted
                that Riverside Bayview upheld ``jurisdiction over wetlands that
                actually abutted on a navigable waterway'' because the wetlands were
                ``inseparably bound up with the `waters' of the United States.'' Id. at
                167.\28\ As summarized by the SWANCC majority:
                ---------------------------------------------------------------------------
                 \28\ At oral argument during Riverside Bayview, the attorney
                representing the United States characterized the wetland at issue as
                ``in fact an adjacent wetland, adjacent--by adjacent, I mean it is
                immediately next to, abuts, adjoins, borders, whatever other
                adjective you might want to use, navigable waters of the United
                States.'' Transcript of Oral Argument at 16, United States v.
                Riverside Bayview Homes, 474 U.S. 121 (1985) (No. 84-701).
                 It was the significant nexus between the wetlands and
                ``navigable waters'' that informed our reading of the CWA in
                Riverside Bayview Homes. Indeed, we did not ``express any opinion''
                on the ``question of authority of the Corps to regulate discharges
                of fill material into wetlands that are not adjacent to bodies of
                open water . . . .'' In order to rule for [the Corps] here, we would
                have to hold that the jurisdiction of the Corps extends to ponds
                that are not adjacent to open water. But we conclude that the text
                ---------------------------------------------------------------------------
                of the statute will not allow this.
                Id. at 167-68 (internal citations and emphasis omitted).
                 The Court also rejected the argument that the use of the abandoned
                ponds by migratory birds fell within the power of Congress to regulate
                activities that in the aggregate have a substantial effect on
                interstate commerce, or that the CWA regulated the use of the ponds as
                a municipal landfill because such use was commercial in nature. Id. at
                173. Such arguments, the Court noted, raised ``significant
                constitutional questions.'' Id. ``Where an administrative
                interpretation of a statute invokes the outer limits of Congress'
                power, we expect a clear indication that Congress intended that
                result.'' Id. at 172-73 (``Congress does not casually authorize
                administrative agencies to interpret a statute to push the limit of
                congressional authority.''). This is particularly true ``where the
                administrative interpretation alters the federal-state framework by
                permitting federal encroachment upon a traditional state power.'' Id.
                at 173; see also Will v. Michigan Dep't of State Police, 491 U.S. 58,
                65 (1989) (``[I]f Congress intends to alter the `usual constitutional
                balance between the States and the Federal Government,' it must make
                its intention to do so `unmistakably clear in the language of the
                statute.' '' (quoting Atascadero State Hospital v. Scanlon, 473 U.S.
                234, 242 (1985))); Gregory v. Ashcroft, 501 U.S. 452, 460-61 (1991)
                (``[The] plain statement rule . . . acknowledg[es] that the States
                retain substantial sovereign powers under our constitutional scheme,
                powers with which Congress does not readily interfere.''). ``Rather
                than expressing a desire to readjust the federal-state balance in this
                manner, Congress chose [in the CWA] to `recognize, preserve, and
                protect the primary responsibilities and rights of States . . . to plan
                the development and use . . . of land and water resources . . . .''
                SWANCC, 531 U.S. at 174 (quoting 33 U.S.C. 1251(b)). The Court found no
                clear statement from Congress that it had intended to permit federal
                encroachment on traditional State power and construed the CWA to avoid
                the significant constitutional questions related to the scope of
                federal authority authorized therein. Id.\29\
                ---------------------------------------------------------------------------
                 \29\ The agencies note that during oral argument in SWANCC,
                Justice Kennedy stated, ``[T]his case, it seems to me, does point up
                the problem that petitioner's counsel raised quoting from page 1 of
                the blue brief, `it is the primary responsibility of the states to
                eliminate pollution and to plan development and use of land' . . . .
                It seems to me that this illustrates that the way in which the Corps
                has promulgated its regulation departs from the design of the
                statute.'' Transcript of Oral Argument at 40, Solid Waste Agency of
                Northern Cook County v. U.S. Army Corps of Engineers, 531 U.S. 159
                (2001) (No. 99-1178) (emphasis added). And several years later,
                during oral argument in Rapanos, after the U.S. Solicitor General
                stated, ``[W]hat Congress recognized in 1972 is that they had to
                regulate beyond traditional navigable waters,'' Justice Kennedy
                stated, ``But the Congress in 1972 also . . . said it's a statement
                of policy to reserve to the States the power and the responsibility
                to plan land use and water resources. And under your definition, I
                just see that we're giving no scope at all to that clear statement
                of the congressional policy.'' Transcript of Oral Argument at 58,
                Rapanos v. United States and Carabell v. United States, 547 U.S. 715
                (2006) (Nos. 04-1034, 04-1384). Although the agencies do not give
                independent weight to these statements at oral argument, the
                statements are consistent with the agencies' interpretation of the
                CWA and applicable Supreme Court decisions.
                ---------------------------------------------------------------------------
                 Historically, the Federal government has interpreted and applied
                the SWANCC decision more narrowly, focusing on the specific holding in
                the case as rejecting federal jurisdiction over the isolated ponds and
                mudflats at issue in that case based on their use by migratory birds.
                By contrast, members of the regulated community, certain States and
                other interested stakeholders have
                [[Page 22265]]
                argued that SWANCC stands for a broader proposition based on key
                federalism and separation of powers principles.\30\ In the preamble to
                the proposed rule, the agencies solicited comment as to the proper
                scope and interpretation of SWANCC. 84 FR 4165. Some commenters argued
                that the SWANCC decision should be interpreted narrowly to apply only
                to the facts presented in that case; other commenters argued that the
                agencies should apply the reasoning of the SWANCC decision broadly, in
                a manner similar to how the agencies had previously interpreted the
                reasoning of Justice Kennedy's concurring opinion in Rapanos to extend
                beyond wetlands to tributaries and other waters, for example. The
                agencies agree with commenters that the interpretation and
                implementation of these Supreme Court decisions within agency
                regulatory programs should be consistent, and that the reasoning in the
                SWANCC decision stands for key principles related to federalism and the
                balancing of the traditional power of States to regulate land and water
                resources within their borders with the need for national water quality
                regulation.
                ---------------------------------------------------------------------------
                 \30\ The agencies also recognize that Justice Stevens, writing
                for himself and three other Justices in dissent in SWANCC,
                interpreted the SWANCC majority opinion to apply beyond the
                Migratory Bird Rule and the specific ponds at issue in SWANCC. His
                dissent stated that the decision ``invalidates the 1986 migratory
                bird regulation as well as the Corps' assertion of jurisdiction over
                all waters except for actually navigable waters, their tributaries,
                and wetlands adjacent to each.'' 531 U.S. at 176-77 (Stevens, J.,
                dissenting) (emphasis added).
                ---------------------------------------------------------------------------
                 The agencies recently repealed the 2015 Rule and explained in the
                preamble of that action that the 2015 Rule had improperly allowed for
                the application of the significant nexus standard in a manner that
                would result in the assertion of jurisdiction over waters that the
                Court deemed non-jurisdictional in SWANCC. 84 FR 56626-27. By allowing
                federal jurisdiction to reach certain isolated ponds, such as those at
                issue in SWANCC, and certain physically remote wetlands that ``do not
                implicate the boundary-drawing problem of Riverside Bayview,'' the
                agencies concluded that the 2015 Rule asserted federal control over
                some features that ``lack the necessary connection to covered waters .
                . . described as a `significant nexus' in SWANCC[.]'' Rapanos, 547 U.S.
                at 742 (Scalia, J., plurality); see also Hawkes, 136 S. Ct. at 1817
                (Kennedy, J., concurring in the judgment) (``[T]he reach and systemic
                consequences of the Clean Water Act remain a cause for concern.''
                (emphasis added)). This final rule, in contrast to the 2015 Rule,
                avoids pressing against the outer limits of the agencies' authority
                under the Commerce Clause and Supreme Court case law and recognizes the
                limiting principles articulated by the SWANCC decision. This final rule
                would not allow for the exercise of jurisdiction over waters similar to
                those at issue in SWANCC.
                 Several years after SWANCC, the Supreme Court considered the
                concept of adjacency in consolidated cases arising out of the Sixth
                Circuit. See Rapanos v. United States, 547 U.S. 715 (2006). In one
                case, the Corps had determined that wetlands on three separate sites
                were subject to CWA jurisdiction because they were adjacent to ditches
                or man-made drains that eventually connected to traditional navigable
                waters several miles away through other ditches, drains, creeks, and
                rivers. Id. at 719-20, 729. In another case, the Corps had asserted
                jurisdiction over a wetland separated from a man-made drainage ditch by
                a four-foot-wide man-made berm. Id. at 730. The ditch emptied into
                another ditch, which then connected to a creek, and eventually
                connected to Lake St. Clair,\31\ a traditional navigable water,
                approximately a mile from the parcel at issue. The berm was largely or
                entirely impermeable but may have permitted occasional overflow from
                the wetland to the ditch. Id. The Court, in a fractured opinion,
                vacated and remanded the Sixth Circuit's decision upholding the Corps'
                asserted jurisdiction over the four wetlands at issue, with Justice
                Scalia writing for the plurality and Justice Kennedy concurring in the
                judgment but on alternative grounds. Id. at 757 (Scalia, J.,
                plurality); id. at 787 (Kennedy, J., concurring in the judgment).
                ---------------------------------------------------------------------------
                 \31\ Lake St. Clair is a Rivers and Harbors Act section 10
                water. See p. 7: https://www.lre.usace.army.mil/Portals/69/docs/regulatory/PDFs/GENSEC10.pdf. It is also described in Justice
                Kennedy's opinion in Rapanos as ``a 430-square mile lake located
                between Michigan and Canada that is popular with boating and fishing
                and produces some 48 percent of the sport fish caught in the Great
                Lakes[.]'' Rapanos, 547 U.S. at 764 (Kennedy, J., concurring in the
                judgment).
                ---------------------------------------------------------------------------
                 The plurality determined that CWA jurisdiction extended to only
                adjacent ``wetlands with a continuous surface connection to bodies that
                are `waters of the United States' in their own right, so that there is
                no clear demarcation between `waters' and wetlands.'' Rapanos, 547 U.S.
                at 742 (Scalia, J., plurality). The plurality then concluded that
                ``establishing . . . wetlands . . . covered by the Act requires two
                findings: First, that the adjacent channel contains a `wate[r] of the
                United States,' (i.e., a relatively permanent body of water connected
                to traditional interstate navigable waters); and second, that the
                wetland has a continuous surface connection with that water, making it
                difficult to determine where the `water' ends and the `wetland'
                begins.'' Id. (alteration in original).
                 In reaching the adjacency component of the two-part analysis, the
                plurality interpreted Riverside Bayview and the Court's subsequent
                SWANCC decision characterizing Riverside Bayview as authorizing
                jurisdiction over wetlands that physically abutted traditional
                navigable waters. Id. at 740-42. The plurality focused on the
                ``inherent ambiguity'' described in Riverside Bayview in determining
                where on the continuum between open waters and dry land the scope of
                federal jurisdiction should end. Id. at 740. It was ``the inherent
                difficulties of defining precise bounds to regulable waters,'' id. at
                741 n.10, according to the plurality, that prompted the Court in
                Riverside Bayview to defer to the Corps' inclusion of adjacent wetlands
                as ``waters'' subject to CWA jurisdiction based on proximity. Id. at
                741 (``When we characterized the holding of Riverside Bayview in
                SWANCC, we referred to the close connection between waters and the
                wetlands they gradually blend into: `It was the significant nexus
                between the wetlands and `navigable waters' that informed our reading
                of the CWA in Riverside Bayview Homes.' ''); see also Riverside
                Bayview, 474 U.S. at 134 (``For this reason, the landward limit of
                Federal jurisdiction under Section 404 must include any adjacent
                wetlands that form the border of or are in reasonable proximity to
                other waters of the United States, as these wetlands are part of this
                aquatic system.'' (quoting 42 FR 37128 (July 19, 1977))). The plurality
                also noted that ``SWANCC rejected the notion that the ecological
                considerations upon which the Corps relied in Riverside Bayview . . .
                provided an independent basis for including entities like `wetlands'
                (or `ephemeral streams') within the phrase `the waters of the United
                States.' SWANCC found such ecological considerations irrelevant to the
                question whether physically isolated waters come within the Corps'
                jurisdiction.'' Rapanos, 547 U.S. at 741-42 (emphasis in original).
                 Justice Kennedy disagreed with the plurality's conclusion that
                adjacency requires a ``continuous surface connection'' to covered
                waters. Id. at 772 (Kennedy, J., concurring in the judgment). In
                reading the phrase ``continuous surface connection'' to mean a
                continuous ``surface-water connection,'' id. at 776 (emphasis
                [[Page 22266]]
                added), and interpreting the plurality's standard to include a
                ``surface-water-connection requirement,'' id. at 774 (emphasis added),
                Justice Kennedy stated that ``when a surface-water connection is
                lacking, the plurality forecloses jurisdiction over wetlands that abut
                navigable-in-fact waters--even though such navigable waters were
                traditionally subject to federal authority.'' Id. at 776. He noted that
                the Riverside Bayview Court ``deemed it irrelevant whether `the
                moisture creating the wetlands . . . find[s] its source in the adjacent
                bodies of water.'' Id. at 772 (internal citations omitted); see also
                Riverside Bayview, 474 U.S. at 134 (``[A]djacent wetlands may be
                defined as waters under the Act. This holds true even for wetlands that
                are not the result of flooding or permeation by water having its source
                in adjacent bodies of open water.'').
                 The plurality did not directly address the precise distinction
                raised by Justice Kennedy regarding his interpretation of the
                plurality's ``continuous surface connection'' requirement to mean a
                continuous ``surface-water connection.'' The plurality did note in
                response, however, that the ``Riverside Bayview opinion required'' a
                ``continuous physical connection,'' Rapanos, 547 U.S. at 751 n.13
                (Scalia, J., plurality) (emphasis added), and focused on evaluating
                adjacency between a ``water'' and a wetland ``in the sense of
                possessing a continuous surface connection that creates the boundary-
                drawing problem we addressed in Riverside Bayview.'' Id. at 757. The
                plurality also noted that its standard includes a ``physical-connection
                requirement,'' not hydrological, between wetlands and covered waters.
                Id. at 751 n.13 (emphasis added). In other words, the plurality
                appeared to be more focused on the abutting nature rather than the
                source of water creating the wetlands at issue in Riverside Bayview to
                describe the legal constructs applicable to adjacent wetlands. See id.
                at 747; see also Webster's II, New Riverside University Dictionary
                (1994) (defining ``abut'' to mean ``to border on'' or ``to touch at one
                end or side of something''). The plurality agreed with Justice Kennedy
                and the Riverside Bayview Court that ``[a]s long as the wetland is
                `adjacent' to covered waters . . . its creation vel non by inundation
                is irrelevant.'' Rapanos, 547 U.S. at 751 n.13 (Scalia, J.,
                plurality).\32\
                ---------------------------------------------------------------------------
                 \32\ In the Rapanos Guidance, the agencies interpreted the
                plurality's ``continuous surface connection'' as not requiring a
                continuous surface water connection. See, e.g., Rapanos Guidance at
                7 n.28 (``A continuous surface connection does not require surface
                water to be continuously present between the wetland and the
                tributary.''). The agencies continue to endorse that interpretation.
                In Rapanos, both Justice Scalia and Justice Kennedy recognized that
                a wetland can be adjacent to a jurisdictional water absent
                inundation from that water.
                ---------------------------------------------------------------------------
                 Because wetlands with a physically remote hydrologic connection do
                not raise the same boundary-drawing concerns presented by actually
                abutting wetlands, the plurality determined that the ``inherent
                ambiguity in defining where water ends and abutting (`adjacent')
                wetlands begin'' upon which Riverside Bayview rests does not apply to
                such features. Id. at 742 (``Wetlands with only an intermittent,
                physically remote hydrologic connection to `waters of the United
                States' do not implicate the boundary-drawing problem of Riverside
                Bayview, and thus lack the necessary connection to covered waters that
                we described as a `significant nexus' in SWANCC[.]''). The plurality
                supported this position by referring to the Court's treatment of
                certain isolated waters in SWANCC as non-jurisdictional. Rapanos, 547
                U.S. at 741-42; see also id. at 726 (``We held that `nonnavigable,
                isolated, intrastate waters--which, unlike the wetlands at issue in
                Riverside Bayview, did not `actually abu[t] on a navigable waterway,'--
                were not included as `waters of the United States.' '') (internal
                citations omitted). It interpreted the reasoning of SWANCC to exclude
                isolated waters. The plurality also found ``no support for the
                inclusion of physically unconnected wetlands as covered `waters' ''
                based on Riverside Bayview's treatment of the Corps' definition of
                adjacent. Id. at 747; see also id. at 746 (``[T]he Corps' definition of
                `adjacent' . . . has been extended beyond reason . . . .'').
                 Although ultimately concurring in the judgment, Justice Kennedy
                focused on the ``significant nexus'' between adjacent wetlands and
                traditional navigable waters as the basis for determining whether a
                wetland is a water subject to CWA jurisdiction. He quotes the SWANCC
                decision, which explains that ``[i]t was the significant nexus between
                the wetlands and `navigable waters' that informed our reading of the
                [Act] in Riverside Bayview Homes.'' SWANCC, 531 U.S. at 167. But
                Justice Kennedy also interpreted the reasoning of SWANCC to exclude
                certain isolated waters. His opinion notes that: ``Because such a nexus
                [in that case] was lacking with respect to isolated ponds, the Court
                held that the plain text of the statute did not permit the Corps'
                action.'' Rapanos, 547 U.S. at 767 (Kennedy, J., concurring in the
                judgment) (internal citation omitted). It further states that the
                wetlands at issue in Riverside Bayview were ``adjacent to [a]
                navigable-in-fact waterway[ ]'' while the ``ponds and mudflats''
                considered in SWANCC ``were isolated in the sense of being unconnected
                to other waters covered by the Act.'' Id. at 765-66. ``Taken together,
                these cases establish that in some instances, as exemplified by
                Riverside Bayview, the connection between a nonnavigable water or
                wetland and a navigable water may be so close, or potentially so close,
                that the Corps may deem the water or wetland a `navigable water' under
                the Act. In other instances, as exemplified by SWANCC, there may be
                little or no connection. Absent a significant nexus, jurisdiction under
                the Act is lacking.'' Id. at 767.
                 According to Justice Kennedy, whereas the isolated ponds and
                mudflats in SWANCC lacked a ``significant nexus'' to navigable waters,
                it is the ``conclusive standard for jurisdiction'' based on ``a
                reasonable inference of ecological interconnection'' between adjacent
                wetlands and navigable-in-fact waters that allows for their categorical
                inclusion as ``waters of the United States.'' Rapanos, 547 U.S. at 780
                (``[T]he assertion of jurisdiction for those wetlands [adjacent to
                navigable-in-fact waters] is sustainable under the Act by showing
                adjacency alone.''). Justice Kennedy surmised that it may be that the
                same rationale ``without any inquiry beyond adjacency . . . could apply
                equally to wetlands adjacent to certain major tributaries.'' Id. He
                noted that the Corps could establish by regulation categories of
                tributaries based on volume of flow, proximity to navigable waters, or
                other relevant factors that ``are significant enough that wetlands
                adjacent to them are likely, in the majority of cases, to perform
                important functions for an aquatic system incorporating navigable
                waters.'' Id. at 780-81. However, ``[t]he Corps' existing standard for
                tributaries'' provided Justice Kennedy ``no such assurance'' to infer
                the categorical existence of a requisite nexus between waters
                traditionally understood as navigable and wetlands adjacent to
                nonnavigable tributaries. Id. at 781. That is because:
                 [T]he breadth of the [tributary] standard--which seems to leave
                wide room for regulation of drains, ditches, and streams remote from
                any navigable-in-fact water and carrying only minor water volumes
                towards it--precludes its adoption as the determinative measure of
                whether adjacent wetlands are likely to play an important role in
                the integrity of an aquatic system comprising navigable waters as
                traditionally understood. Indeed, in many cases, wetlands
                [[Page 22267]]
                adjacent to tributaries covered by this standard might appear little
                more related to navigable-in-fact waters than were the isolated
                ponds held to fall beyond the Act's scope in SWANCC.
                Rapanos, 547 U.S. at 781-82.
                 To avoid this outcome, Justice Kennedy stated that, absent
                development of a more specific regulation and categorical inclusion of
                wetlands adjacent to ``certain major'' or even ``minor'' tributaries as
                was established in Riverside Bayview, id. at 780-81, the Corps ``must
                establish a significant nexus on a case-by-case basis when it seeks to
                regulate wetlands based on adjacency to nonnavigable tributaries. Given
                the potential overbreadth of the Corps' regulations, this showing is
                necessary to avoid unreasonable applications of the statute.'' Id. at
                782. Justice Kennedy stated that adjacent ``wetlands possess the
                requisite nexus, and thus come within the statutory phrase `navigable
                waters,' if the wetlands, either alone or in combination with similarly
                situated lands in the region, significantly affect the chemical,
                physical, and biological integrity of other covered waters more readily
                understood as `navigable.' '' Id. at 780. ``Where an adequate nexus is
                established for a particular wetland, it may be permissible, as a
                matter of administrative convenience or necessity, to presume covered
                status for other comparable wetlands in the region.'' Id. at 782. In
                establishing this significant nexus test, Justice Kennedy relied, in
                part, on the overall objective of the CWA to ``restore and maintain the
                chemical, physical and biological integrity of the Nation's waters.''
                Id. at 779 (quoting 33 U.S.C. 1251(a)). However, Justice Kennedy also
                acknowledged that ``environmental concerns provide no reason to
                disregard limits in the statutory text.'' Id. at 778. With respect to
                wetlands adjacent to nonnavigable tributaries, Justice Kennedy
                therefore determined that ``mere adjacency . . . is insufficient[.] A
                more specific inquiry, based on the significant-nexus standard, is . .
                . necessary.'' Id. at 786. Justice Kennedy noted that under the Corps'
                interpretation at issue in the case, which did not require adjacent
                wetlands to possess a significant nexus with navigable waters, federal
                regulation would be permitted ``whenever wetlands lie alongside a ditch
                or drain, however remote or insubstantial, that eventually may flow
                into traditional navigable waters. The deference owed to the Corps'
                interpretation of the statute does not extend so far.'' Id. at 778-79.
                 Since the Rapanos decision, the Federal government has adopted a
                broad interpretation of Justice Kennedy's concurring opinion, arguing
                that his ``significant nexus'' test provides an independent basis for
                establishing jurisdiction over certain waters of the United States. And
                rather than limiting the application of Justice Kennedy's opinion to
                the specific facts and wetlands at issue in that case, similar to their
                treatment of the SWANCC decision, the agencies previously have applied
                Justice Kennedy's reasoning more broadly to include, for example, the
                application of the significant nexus test to determining jurisdiction
                over tributaries, not just wetlands. Many courts have deferred to this
                position, and some courts rely exclusively on Justice Kennedy's
                significant nexus test while other courts have held that jurisdiction
                can be established under either the plurality or concurring opinions.
                The agencies' final rule, as explained in Section III, is informed in
                several key aspects by Justice Kennedy's opinion, but the agencies now
                appropriately recognize some of the limiting principles articulated
                within his concurring opinion. The agencies also recognize that the
                reasoning in SWANCC contains more instruction than the agencies have
                historically acknowledged.
                 In summary, although the standards that the Rapanos plurality and
                Justice Kennedy established are not identical, and each standard
                excludes some waters and wetlands that the other standard does not, the
                standards contain substantial similarities. The plurality and Justice
                Kennedy agreed in principle that the determination must be made using a
                basic two-step approach that considers (1) the connection of the
                wetland to the tributary; and (2) the status of the tributary with
                respect to downstream traditional navigable waters. The plurality and
                Justice Kennedy also agreed that the connection between the wetland and
                the tributary must be close. The plurality referred to that connection
                as a ``continuous surface connection'' or ``continuous physical
                connection,'' as demonstrated in Riverside Bayview. Id. at 742, 751
                n.13. Justice Kennedy recognized that ``the connection between a
                nonnavigable water or wetland and a navigable water may be so close, or
                potentially so close, that the Corps may deem the water or wetland a
                `navigable water' under the Act.'' Id. at 767. The second part of their
                common analytical framework is addressed in the next section.
                b. Tributaries
                 As some commenters noted, the definition of ``tributary'' was not
                addressed in either Riverside Bayview or SWANCC, nor were tributaries
                the waters at issue in Rapanos. Yet while the focus of Rapanos was on
                whether the Corps could regulate wetlands adjacent to nonnavigable
                tributaries far removed from navigable-in-fact waters, the plurality
                and concurring opinions provide some guidance as to the scope of CWA
                coverage of tributaries to waters more traditionally understood as
                navigable.
                 The plurality and Justice Kennedy both recognized the
                jurisdictional scope of the CWA is not restricted to traditional
                navigable waters. Rapanos, 547 U.S. at 731 (Scalia, J., plurality)
                (``[T]he Act's term `navigable waters' includes something more than
                traditional navigable waters.''); id. at 767 (Kennedy, J., concurring
                in the judgment) (``Congress intended to regulate at least some waters
                that are not navigable in the traditional sense.''). Both also agreed
                that federal authority under the Act has limits. See id. at 731-32
                (Scalia, J., plurality) (`` `[T]he waters of the United States' . . .
                cannot bear the expansive meaning that the Corps would give it.''); id.
                at 778-79 (Kennedy, J., concurring in the judgment) (``The deference
                owed to the Corps' interpretation of the statute does not extend'' to
                ``wetlands'' which ``lie alongside a ditch or drain, however remote or
                insubstantial, that eventually may flow into traditional navigable
                waters.'').
                 With respect to tributaries specifically, both the plurality and
                Justice Kennedy focused in part on a tributary's contribution of flow
                to and connection with traditional navigable waters. The plurality
                would include as ``waters of the United States'' ``only relatively
                permanent, standing or flowing bodies of water'' and would define such
                ``waters'' as including streams, rivers, oceans, lakes and other bodies
                of waters that form geographical features, noting that all such ``terms
                connote continuously present, fixed bodies of water.'' Rapanos, 547
                U.S. at 732-33, 739 (Scalia, J., plurality). The plurality would have
                also required relatively permanent waters to be connected to
                traditional navigable waters in order to be jurisdictional. See id. at
                742 (describing a `` `wate[r] of the United States' '' as ``i.e., a
                relatively permanent body of water connected to traditional interstate
                navigable waters'') (emphasis added). The plurality would also have
                excluded ephemeral flows and related features, stating ``[n]one of
                these terms encompasses transitory puddles or ephemeral flows of
                water.'' Id. at 733; see also id. at 734 (``In applying the definition
                to `ephemeral streams,' . . .
                [[Page 22268]]
                the Corps has stretched the term `waters of the United States' beyond
                parody. The plain language of the statute simply does not authorize
                this `Land Is Waters' approach to federal jurisdiction.''). Justice
                Kennedy likely would exclude some streams considered jurisdictional
                under the plurality's opinion, but he may include some that would be
                excluded by the plurality. See id. at 769 (Kennedy, J., concurring in
                the judgment) (noting that under the plurality's test, ``[t]he merest
                trickle, if continuous, would count as a `water' subject to federal
                regulation, while torrents thundering at irregular intervals through
                otherwise dry channels would not'').
                 Both the plurality and Justice Kennedy would have included some
                seasonal or intermittent streams as waters of the United States.
                Rapanos, 547 U.S. at 732 n.5, 733 (Scalia, J., plurality); id. at 769
                (Kennedy, J., concurring in the judgment). The plurality noted, for
                example, that its reference to ``relatively permanent'' waters did
                ``not necessarily exclude streams, rivers, or lakes that might dry up
                in extraordinary circumstances, such as drought,'' or ``seasonal
                rivers, which contain continuous flow during some months of the year
                but no flow during dry months.'' Id. at 732 n.5 (emphasis in original).
                Neither the plurality nor Justice Kennedy, however, defined with
                precision where to draw the line. See, e.g., id. (Scalia, J.,
                plurality) (``[W]e have no occasion in this litigation to decide
                exactly when the drying-up of a stream bed is continuous and frequent
                enough to disqualify the channel as a `wate[r] of the United States.'
                It suffices for present purposes that channels containing permanent
                flow are plainly within the definition, and that . . . streams whose
                flow is `[c]oming and going at intervals . . . [b]roken, fitful,' . . .
                or `existing only, or no longer than, a day; diurnal . . . short-
                lived,' . . . are not.'') (internal citations omitted). The plurality
                provided, however, that ``navigable waters'' must have ``at a bare
                minimum, the ordinary presence of water,'' id. at 734, and Justice
                Kennedy noted that the Corps can identify by regulation categories of
                tributaries based on ``their volume of flow (either annually or on
                average), their proximity to navigable waters, or other relevant
                considerations'' that ``are significant enough that wetlands adjacent
                to them are likely, in the majority of cases, to perform important
                functions for an aquatic system incorporating navigable waters,'' id.
                at 780-81 (Kennedy, J., concurring in the judgment).
                 Both the plurality and Justice Kennedy also agreed that the Corps'
                existing treatment of tributaries raised significant jurisdictional
                concerns. For example, the plurality was concerned about the Corps'
                broad interpretation of tributaries. See Rapanos, 547 U.S. at 738
                (Scalia, J., plurality) (``Even if the term `the waters of the United
                States' were ambiguous as applied to channels that sometimes host
                ephemeral flows of water (which it is not), we would expect a clearer
                statement from Congress to authorize an agency theory of jurisdiction
                that presses the envelope of constitutional validity.''). And Justice
                Kennedy objected to the categorical assertion of jurisdiction over
                wetlands adjacent to waters deemed tributaries under the Corps' then-
                existing standard, ``which seems to leave wide room for regulation of
                drains, ditches, and streams remote from any navigable-in-fact water
                and carrying only minor water volumes towards it.'' Id. at 781
                (Kennedy, J., concurring in the judgment); see also id. at 781-82
                (``[I]n many cases wetlands adjacent to tributaries covered by this
                standard might appear little more related to navigable-in-fact waters
                than were the isolated ponds held to fall beyond the Act's scope in
                SWANCC.'').
                 Beyond tributaries, the plurality and Justice Kennedy also offered
                some insight regarding CWA jurisdiction with respect to other
                relatively permanent bodies of water, such as lakes and ponds, and
                their connection to traditional navigable waters. The plurality
                describes a ``water of the United States'' as ``a relatively permanent
                body of water connected to traditional interstate navigable waters[.]''
                Id. at 742 (emphasis added). The plurality did not specify, however,
                what would constitute a sufficient connection between such relatively
                permanent waters and downstream traditional navigable waters. When
                considered in the context of Justice Scalia's entire opinion, the
                plurality signaled concern that certain types of connections are likely
                insufficient to maintain jurisdiction; for instance, by characterizing
                an ``expansive definition of `tributaries' '' as one that includes
                ``dry arroyos connected to remote waters through the flow of
                groundwater over `centuries,' '' id. at 725-26 (internal citations
                omitted), and describing potential federal control over ``irrigation
                ditches and drains that intermittently connect to covered waters'' as
                ``sweeping.'' Id. at 726-27. In addition to ``tributaries,'' the
                plurality noted that the Corps and lower courts have ``define[d]
                `adjacent' wetlands broadly'' to include wetlands ``hydrologically
                connected'' ``to covered waters'' ``through directional sheet flow
                during storm events,'' and wetlands ``connected to the navigable water
                by flooding, on average, once every 100 years[.]'' Rapanos, 547 U.S. at
                728 (internal quotations and citations omitted). Justice Kennedy noted
                that ``in some instances, as exemplified by Riverside Bayview, the
                connection between a nonnavigable water . . . and a navigable water may
                be so close, or potentially so close, that the Corps may deem the water
                . . . a `navigable water' under the Act. In other instances, as
                exemplified by SWANCC, there may be little or no connection.'' Id. at.
                767 (Kennedy, J., concurring in the judgment). Justice Kennedy also
                stated that ``mere hydrologic connection should not suffice in all
                cases; the connection may be too insubstantial for the hydrologic
                linkage to establish the required nexus with navigable waters as
                traditionally understood.'' Id. at 784-85.
                 Some commenters agreed that aspects of the plurality's and Justice
                Kennedy's opinions share similarities regarding the limits of federal
                jurisdiction under the CWA, while other commenters disagreed that the
                opinions share important commonalities. These commenters asserted that
                the opinions have disparate rationales that cannot be reconciled. While
                the agencies acknowledge that the plurality and Justice Kennedy viewed
                the question of federal CWA jurisdiction differently, as discussed
                above, the agencies find that there are sufficient commonalities
                between these opinions to help instruct the agencies on where to draw
                the line between Federal and State waters.
                3. Principles and Considerations
                 As discussed in the previous sections, a few important principles
                emerge that can serve as the basis for the agencies' final regulatory
                definition. As a threshold matter, the power conferred on the agencies
                under the CWA to regulate the waters of the United States is grounded
                in Congress' commerce power over navigation. The agencies can choose to
                regulate beyond waters more traditionally understood as navigable,
                including some tributaries and relatively permanent bodies of water
                connected to those traditional navigable waters, but the agencies must
                provide a reasonable basis grounded in the language and structure of
                the Act for determining the extent of jurisdiction. The agencies can
                also choose to regulate wetlands adjacent to covered waters beyond
                those traditionally understood as navigable, if the wetlands are
                closely connected to those waters, such as in the transitional zone
                between open waters and dry land. The Supreme
                [[Page 22269]]
                Court's opinion in SWANCC, however, calls into question the agencies'
                authority to regulate nonnavigable, isolated, intrastate waters that
                lack a sufficient connection to traditional navigable waters. The
                decision counsels that the agencies should avoid regulatory
                interpretations of the CWA that raise constitutional questions
                regarding the scope of their statutory authority. Finally, the agencies
                can regulate certain waters by category, which could improve regulatory
                predictability and certainty and ease administrative burdens while
                still effectuating the purposes of the Act.
                 In developing an appropriate regulatory framework for the final
                rule, the agencies recognize and respect the primary responsibilities
                and rights of States to regulate their land and water resources as
                reflected in CWA section 101(b). 33 U.S.C. 1251(b), see also id. at
                1370. The oft-quoted objective of the CWA to ``restore and maintain the
                chemical, physical, and biological integrity of the Nation's waters,''
                id. at 1251(a), must be implemented in a manner consistent with
                Congress' policy directives to the agencies. The Supreme Court long ago
                recognized the distinction between federal waters traditionally
                understood as navigable and waters ``subject to the control of the
                States.'' The Daniel Ball, 77 U.S. (10 Wall.) 557, 564-65 (1870). Over
                a century later, the Supreme Court in SWANCC reaffirmed the State's
                ``traditional and primary power over land and water use.'' SWANCC, 531
                U.S. at 174; accord Rapanos, 547 U.S. at 738 (Scalia, J., plurality).
                While CWA section 101(b) does not specifically identify Tribes, the
                policy of preserving States' sovereign authority over land and water
                use is equally relevant to ensuring the primary authority of Tribes to
                address pollution and plan the development and use of tribal land and
                water resources. This final rule recognizes and preserves the autonomy
                of Tribes just as it recognizes and preserves the authority of States.
                 Ensuring that States and Tribes retain authority over their land
                and water resources, reflecting the policy in section 101(b), helps
                carry out the overall objective of the CWA and ensures that the
                agencies are giving full effect and consideration to the entire
                structure and function of the Act. See, e.g., Rapanos, 547 U.S. at 755-
                56 (Scalia, J., plurality) (``[C]lean water is not the only purpose of
                the statute. So is the preservation of primary state responsibility for
                ordinary land-use decisions. 33 U.S.C. 1251(b).'') (emphasis in
                original). That includes the dozens of non-regulatory grant, research,
                nonpoint source, groundwater, and watershed planning programs that were
                intended by Congress to assist the States in controlling pollution in
                the nation's waters, not just its navigable waters. These non-
                regulatory sections of the CWA reveal Congress' intent to restore and
                maintain the integrity of the nation's waters using federal assistance
                to support State, tribal, and local partnerships to control pollution
                of the nation's waters in addition to a federal regulatory prohibition
                on the discharge of pollutants to its navigable waters. See e.g., id.
                at 745 (``It is not clear that the state and local conservation efforts
                that the CWA explicitly calls for, see 33 U.S.C. 1251(b), are in any
                way inadequate for the goal of preservation.''). Regulating all of the
                nation's waters using the Act's federal regulatory mechanisms would
                call into question the need for the more holistic planning provisions
                of the Act and the State partnerships they entail. Therefore, by
                recognizing the distinctions between the nation's waters and its
                navigable waters and between the overall objective and goals of the CWA
                and the specific policy directives from Congress, the agencies can
                fully implement the entire structure of the Act while respecting the
                specific word choices of Congress. See, e.g., Bailey, 516 U.S. at 146;
                Nat'l Fed'n of Indep. Bus., 567 U.S. at 544.
                 Some commenters agreed with the interpretation that the CWA
                establishes a comprehensive scheme to achieve the Act's objective
                through a combination of non-regulatory programs and grants for all of
                the nation's waters, and a more targeted federal permitting program for
                discharges of pollutants to the subset of the nation's waters
                identified as waters of the United States. Other commenters expressed
                concern that the proposed rule would not further the CWA's objective to
                ``restore and maintain the chemical, physical, and biological integrity
                of the Nation's waters,'' 33 U.S.C. 1251(a), because fewer waters would
                be jurisdictional under the proposal than were regulated under the 2015
                Rule or the pre-2015 regulatory regime. The agencies disagree with
                these commenters. The agencies are mindful that ``no legislation
                pursues its purposes at all costs,'' Rodriguez v. United States, 480
                U.S. 522, 525-26 (1987), including the CWA. The CWA's objective must be
                balanced with the policy of Congress to preserve the primary State
                responsibility for ordinary land-use decisions. The purpose of this
                rulemaking is to establish the boundary between regulated ``waters of
                the United States'' and the waters subject solely to State and tribal
                authority. The CWA's longstanding regulatory permitting programs,
                coupled with the controls that States, Tribes, and local entities
                choose to exercise over their land and water resources, will continue
                to address the discharge of pollutants into waters of the United
                States, and the CWA's non-regulatory measures will continue to address
                pollution of the nation's waters generally. These programs and measures
                collectively pursue the objective of restoring and maintaining the
                chemical, physical, and biological integrity of the nation's waters.
                 Some commenters agreed with the statements in the preamble to the
                proposed rule that the CWA preserves a significant and primary role for
                the States in implementing various aspects of the CWA, reflecting an
                intent to balance the States' traditional powers to regulate land and
                water resources within their borders with the need for national water
                quality regulation. Other commenters stated that section 101(b) is
                primarily concerned with State implementation of water pollution
                control measures, not the jurisdictional reach of the Act, and that a
                lawful and protective definition of jurisdictional waters under the Act
                does not disturb or undermine the States' exercise of primary
                authority. Rather, they expressed concern that the rule would harm the
                States in exercising their authority as envisioned by section 101(b)
                by, for example, increasing the financial and administrative burden on
                States to protect their waters.
                 The agencies interpret the policy of Congress, set forth in section
                101(b), as relevant to all aspects of the implementation of the CWA,
                both implementing federally-established standards as well as the scope
                of waters subject to such standards and regulatory programs. When
                promulgating the 2015 Rule, the agencies endorsed a narrower view of
                Congress' policy in section 101(b) as limited to implementation of the
                Act's regulatory programs by States and State authority to impose
                conditions on ``waters of the United States'' that are more stringent
                than the conditions that the agencies impose under the Act. In the
                final Step One Rule, the agencies concluded that such a view was
                improperly narrow and failed to place sufficient weight on the policy
                of Congress in section 101(b). See 84 FR 56654. Having considered the
                public comments submitted in this rulemaking, the agencies remain of
                the view that nothing in section 101(b) suggests that it is limited to
                implementing federal regulatory programs or imposing conditions on
                [[Page 22270]]
                ``waters of the United States'' that are more stringent than the
                conditions that the agencies impose under the Act. Indeed, the
                overarching policy statement of 101(b) ``to recognize, preserve, and
                protect the primary responsibilities and rights of States to prevent,
                reduce, and eliminate pollution, to plan the development and use . . .
                of land and water resources,'' was included in the Act in 1972; the
                additional 101(b) policy statement ``that the States . . . implement
                the permit programs under sections 402 and 404 of this Act'' was not
                added until the 1977 amendments. 91 Stat. 1567, 1575 Public Law 95-217
                (1977); see also Rapanos, 547 U.S. at 737 (Scalia, J., plurality)
                (``Thus, the policy [to recognize, preserve, and protect the primary
                responsibilities and rights of States to prevent, reduce, and eliminate
                pollution, to plan the development and use . . . of land and water
                resources] plainly referred to something beyond the subsequently added
                state administration program of 33 U.S.C. 1344(g)-(l).'') (citations
                omitted). The agencies acknowledge that States without comprehensive
                pre-existing programs that seek to regulate waters no longer
                jurisdictional under this final rule may incur new costs and
                administrative burdens, and they discuss those costs in the Economic
                Analysis for the final rule. Such obligations are inherent in the
                exercise of the States' authority that Congress embedded in the CWA.
                States are free to evaluate the most effective means of addressing
                their waters and may weigh the costs and benefits of doing so.
                 The agencies also heard from Tribes that because the agencies
                generally implement CWA programs on tribal lands, the proposed rule
                would affect Tribes differently than it would affect most States. Some
                Tribes have received Treatment as a State status to administer CWA
                programs, and other Tribes have established tribal water programs under
                tribal law or have the authority to establish such tribal water
                programs. Other Tribes may currently lack the capacity to create a
                tribal water program, to administer a program, or to expand programs
                that currently exist, and may rely on the Federal government for
                enforcement of water quality violations. See Chapter III of the
                Resource and Programmatic Assessment (RPA) for the final rule. The
                final rule preserves tribal authority to choose whether or not to
                regulate waters that are not covered under the CWA.
                 The agencies are also cognizant that the ``Clean Water Act imposes
                substantial criminal and civil penalties for discharging any pollutant
                into waters covered by the Act without a permit.'' Hawkes, 136 S. Ct.
                at 1812; see also Sackett, 132 S. Ct. at 1374-75 (Alito, J.,
                concurring) (``[T]he combination of the uncertain reach of the Clean
                Water Act and the draconian penalties imposed for the sort of
                violations alleged in this case still leaves most property owners with
                little practical alternative but to dance to the EPA's tune.''). As the
                Chief Justice observed in Hawkes, ``[i]t is often difficult to
                determine whether a particular piece of property contains waters of the
                United States, but there are important consequences if it does.'' 136
                S. Ct. at 1812; see also id. at 1816-17 (Kennedy, J., concurring in the
                judgment) (stating that ``the reach and systemic consequences of the
                Clean Water Act remain a cause for concern'' and ``continue[] to raise
                troubling questions regarding the Government's power to cast doubt on
                the full use and enjoyment of private property throughout the
                Nation''). Given the significant civil and criminal penalties
                associated with the CWA, the agencies seek to promote regulatory
                certainty and to provide fair and predictable notice of the limits of
                federal jurisdiction. A number of commenters expressed support for the
                emphasis on the importance of fair notice in the proposed rule and
                cited in support Justice Gorsuch's concurring opinion in Sessions v.
                Dimaya, 138 S. Ct. 1204, 1223-25 (2018) (characterizing fair notice as
                possibly the most fundamental of the customary protections provided by
                the Constitution's guarantee of due process, and stating that vague
                laws are an exercise of ``arbitrary power . . . leaving the people in
                the dark about what the law demands and allowing prosecutors and courts
                to make it up'').
                 The agencies interpret their authority to include promulgation of a
                new regulatory definition of ``waters of the United States,'' as
                directed by Executive Order 13778, so long as the new definition is
                authorized under the law and based on a reasoned explanation. FCC v.
                Fox Television Stations, Inc., 556 U.S. 502, 515 (2009) (``Fox''). A
                revised rulemaking based on a change in interpretation of statutory
                authorities is well within federal agencies' discretion. Nat'l Ass'n of
                Home Builders v. EPA, 682 F.3d 1032, 1038 (D.C. Cir. 2012) (citing Fox,
                556 U.S. at 514-15). Under this rule, the agencies do not view the
                definition of ``waters of the United States'' as conclusively
                determining which of the nation's waters warrant environmental
                protection and which do not; rather, the agencies interpret the
                definition as drawing the boundary between those waters subject to
                federal requirements under the CWA and those waters that States and
                Tribes are free to manage under their independent authorities. The
                agencies are establishing this line-drawing based primarily on their
                interpretation of their authority under the Constitution and the
                language, structure, and legislative history of the CWA, as articulated
                in decisions by the Supreme Court.
                 Some commenters viewed the proposed rule as complicated and,
                because one of the agencies' goals in proposing a new definition was to
                provide simplicity and clarity, stated that the proposal failed to meet
                that goal and is therefore arbitrary and capricious. The agencies
                disagree with these commenters' view that the proposed rule would not
                have provided necessary clarity. Notwithstanding this disagreement, the
                agencies have made certain enhancements to the final rule that will
                further promote clarity and provide fair notice to the public. As a
                threshold matter, the agencies for the first time have streamlined the
                regulatory text to four simple categories of jurisdictional waters,
                provided clear exclusions for many water features that traditionally
                have not been regulated, and defined the operative terms used in the
                regulatory text. And while the categories of jurisdiction in the final
                rule must be applied to specific facts to determine jurisdiction, the
                final rule does not include a regulatory category of case-specific
                jurisdiction as the 2015 Rule did in paragraphs (a)(7) and (a)(8). As
                such, the agencies believe the final rule will be clearer than either
                the 2015 Rule or the pre-existing regulatory regime restored by the
                2019 Rule. However, clarity as an end in itself is not the primary or
                fundamental basis for the final rule.
                 Section III of this notice describes in detail the fundamental
                bases for this rule as the text and structure of the CWA and the
                constitutional boundaries within which Congress enacted the CWA. The
                final rule is securely grounded in the text of the CWA and is supported
                by legislative history and Supreme Court case law. As to simplicity and
                clarity, the agencies acknowledge that field work may frequently be
                necessary to verify whether a feature is a water of the United States;
                however, replacing the multi-factored case-specific significant nexus
                analysis with categorically jurisdictional and categorically excluded
                waters in the final rule provides clarifying value for members of the
                regulated community. The application of a clear test for categorically
                covered and excluded
                [[Page 22271]]
                waters, as presented in this final rule, is inherently less complicated
                than a complex multi-factored significant nexus test that must be
                applied on a case-by-case basis to countless waters and wetlands across
                the nation.
                 Some commenters stated that the agencies' desire to facilitate
                implementation of the regulatory definition does not override the
                agencies' legal obligations under the CWA, including fulfillment of the
                goals of the CWA. The agencies agree in principle. The agencies have
                determined that requiring surface water flow in a typical year from
                relatively permanent bodies of water to traditional navigable waters
                and wetlands adjacent to such waters as a core requirement of the rule
                is the most faithful way of interpreting the Federal government's CWA
                authority over a water. The agencies carefully considered the comments
                received on the proposal and have made certain revisions to the
                regulatory text that provide further clarity without sacrificing or
                undermining the fundamental legal and constitutional bases for the
                rule. A number of commenters stated that the proposed rule failed to
                incorporate scientific and ecological principles into the definition of
                ``waters of the United States.'' The agencies disagree. While science
                informs the agencies' interpretation of the definition of ``waters of
                the United States,'' science cannot dictate where to draw the line
                between Federal and State or tribal waters, as those are legal
                distinctions that have been established within the overall framework
                and construct of the CWA. The definition of ``waters of the United
                States'' must be grounded in a legal analysis of the limits on CWA
                jurisdiction reflected in the statute and Supreme Court case law. The
                agencies are precluded from exceeding their authority under the CWA to
                achieve specific scientific, policy, or other outcomes. Within the
                legal limits of the CWA, the agencies have looked to scientific
                principles to inform implementation of the final rule as the agencies
                differentiate between waters of the United States and non-
                jurisdictional waters and features. For example, and as discussed
                further in Section III.A.1, in requiring the use of a ``typical year''
                scenario to assess the surface water connection between a particular
                water or wetland and a downstream water identified in paragraph (a)(1),
                (2), or (3) (generally referred to as ``paragraph (a)(1) through (3)
                waters'' or ``a paragraph (a)(1) through (3) water'' in this notice),
                the agencies recognize the influence of precipitation,
                evapotranspiration, and other climatic variables on the flow of surface
                water in a tributary and its contribution of flow to downstream waters
                and the hydrologic surface connection between a jurisdictional water
                and an adjacent wetland. In other words, the agencies will evaluate the
                flow regime of a stream and the connectedness of a wetland within the
                context of what is typical for that water or wetland to avoid making
                erroneous jurisdictional determinations at times that may be too wet or
                too dry to be considered ``normal.'' The agencies also looked to
                science to inform other aspects of the final rule; for example, in
                defining the terms ``perennial,'' ``intermittent,'' and ``ephemeral'';
                in establishing that wetlands separated from jurisdictional waters only
                by a natural berm, bank, dune, or similar natural feature are
                ``inseparably bound up with'' and adjacent to those waters; and in
                accounting for the connectivity gradient \33\ in deciding how to apply
                key principles from the Riverside Bayview, SWANCC, and Rapanos
                decisions.
                ---------------------------------------------------------------------------
                 \33\ As part of the 2015 Rule, EPA's SAB stressed that ``the EPA
                should recognize that there is a gradient of connectivity.'' See
                Letter to Gina McCarthy. SAB Review of the Draft EPA Report
                Connectivity of Streams and Wetlands to Downstream Waters: A Review
                and Synthesis of the Scientific Evidence at 3 (Oct. 17, 2014) (``SAB
                Review''). The SAB recommended that ``the interpretation of
                connectivity be revised to reflect a gradient approach that
                recognizes variation in the frequency, duration, magnitude,
                predictability, and consequences of physical, chemical, and
                biological connections.'' Id. at 2 (emphasis added); see also
                Connectivity Report at 1-18 (``Variation in the degree of
                connectivity is critical to the integrity and sustainability of
                downstream waters, and can be described in terms of the frequency,
                duration, magnitude, timing, and rate of change of fluxes to and
                biological exchanges with downstream waters. These descriptors
                characterize the range over which streams and wetlands vary and
                shift along connectivity gradients and the probable effects of
                different types (hydrologic, chemical, biological) and degrees of
                connectivity over time. . . . Ultimately, differences in the
                frequency, duration, magnitude, timing, and rate of change of
                physical, chemical, and biological connections describe different
                positions along the connectivity gradient and produce different
                types of downstream effects.'').
                ---------------------------------------------------------------------------
                 The agencies consider the priorities they have outlined to be
                reasonable, especially in light of the long history of controversy and
                confusion over the definition of ``waters of the United States.'' In
                concurring with the Rapanos plurality opinion, Chief Justice Roberts
                stated that ``[g]iven the broad, somewhat ambiguous, but clearly
                limiting terms Congress employed in the Clean Water Act, the [agencies]
                would have enjoyed plenty of room to operate in developing some notion
                of an outer bound to the reach of their authority'' under the CWA, and
                that the agencies' interpretations under the Act are ``afforded
                generous leeway by the courts.'' Rapanos, 547 U.S. at 758 (Roberts,
                C.J., concurring) (emphasis in original); see also id. (``Rather than
                refining its view of its authority in light of our decisions in SWANCC,
                . . . the Corps chose to adhere to its essentially boundless view of
                the scope of its power. The upshot today is another defeat for the
                agency.''). In this rule, as described in detail in Section III, the
                agencies are reasonably interpreting the scope of their authority under
                the Act in a manner that is consistent with its text, structure,
                legislative history, and applicable Supreme Court guidance. This final
                rule presents a unifying legal theory for federal jurisdiction over
                those waters and wetlands that maintain a sufficient surface water
                connection to traditional navigable waters or the territorial seas.
                F. Summary of Final Rule as Compared to the 1986 Regulations Recodified
                in the 2019 Rule and the 2015 Rule
                 The agencies are finalizing a definition of ``waters of the United
                States'' that they consider to be superior to the 1986 regulations re-
                codified in the 2019 Rule, as well as to the 2015 Rule. The agencies
                are revising previous regulatory definitions of this term to
                distinguish between waters that are ``waters of the United States''
                subject to Federal regulation under the CWA and waters or features that
                are subject to exclusive State or tribal jurisdiction, consistent with
                the scope of jurisdiction authorized under the CWA and the direction in
                the Act to both ``restore and maintain the chemical, physical, and
                biological integrity of the Nation's waters,'' 33 U.S.C. 1251(a), and
                ``recognize, preserve, and protect the primary responsibilities and
                rights of States to . . . plan the development and use (including
                restoration, preservation, and enhancement) of land and water resources
                . . . .'' Id. at 1251(b). The Supreme Court has recognized that new
                administrations may reconsider the policies of their predecessors so
                long as they provide a reasonable basis for the change in approach.
                Nat'l Ass'n of Home Builders, 682 F.3d at 1043 (quoting Motor Vehicle
                Mfrs. Ass'n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 59 (1983)
                (Rehnquist, J., concurring in part and dissenting in part)). The
                agencies intend that the revised interpretation of the federal
                regulatory scope of the CWA will resolve longstanding confusion over
                broad and unclear definitions of ``waters of the United States.''
                 This final rule is more consistent with the agencies'
                constitutional and statutory authority than the 2015 Rule,
                [[Page 22272]]
                for the reasons discussed in the preamble to the 2019 Rule as well as
                the rest of this section and Section III of this notice. The 2015 Rule
                did not implement the legal limits on the scope of the agencies'
                authority under the CWA as intended by Congress and as reflected in
                Supreme Court cases, including Justice Kennedy's articulation of the
                significant nexus test in Rapanos. In the 2019 Rule, the agencies
                concluded that in promulgating the 2015 Rule the agencies failed to
                adequately consider and accord due weight to the policy of the Congress
                in CWA section 101(b) to ``recognize, preserve, and protect the primary
                responsibilities and rights of States to prevent, reduce, and eliminate
                pollution'' and ``to plan the development and use . . . of land and
                water resources.'' 33 U.S.C. 1251(b). The 2015 Rule interpreted the CWA
                in a manner that pushed the envelope of the agencies' constitutional
                and statutory authority in the absence of a clear statement from
                Congress authorizing substantial encroachment upon traditional State
                land-use planning authority. See Georgia v. Wheeler, No. 2:15-cv-079,
                2019 WL 3949922, at *23 (S.D. Ga. Aug. 21, 2019) (finding the 2015 Rule
                ``unlawful'' given its ``significant intrusion on traditional state
                authority'' without ``any clear or manifest statement to authorize
                intrusion into that traditional state power'').
                 In addition, the agencies recognize that the 2015 Rule has been
                remanded by the U.S. District Court for the Southern District of Texas
                for failing to comply with the APA. That court found that the 2015 Rule
                suffered from several problems, including that the distance-based
                limitations in the 2015 Rule were not a logical outgrowth of the
                proposal in violation of the APA's public notice and comment
                requirements. See Texas v. EPA, 389 F. Supp. 3d 497 (S.D. Tex. 2019).
                The court found this error ``significant'' because the specific
                distance-based limitations ``alter[ed] the jurisdictional scope of the
                Act.'' Id. at 504. Litigants challenging the 2015 Rule alleged other
                APA deficiencies, including the lack of record support for the
                distance-based limitations inserted into the final rule without
                adequate notice. Several commenters on the proposed repeal of the 2015
                Rule raised similar concerns, arguing that the 2015 Rule was arbitrary
                and capricious because of the lack of record support for those
                limitations. The agencies recognize that the Federal government, in
                prior briefs before the various district courts that heard challenges
                to the 2015 Rule, defended the procedural steps the agencies took to
                develop and support the 2015 Rule. Having considered the public
                comments and relevant litigation positions, and the decision of the
                Southern District of Texas on related arguments, the agencies concluded
                in the 2019 rulemaking that the administrative record for the 2015 Rule
                did not contain sufficient record support for the distance-based
                limitations that appeared for the first time in that final rule. This
                conclusion is further supported by similar findings of the U.S.
                District Court for the Southern District of Georgia, which remanded the
                2015 Rule to the agencies in August 2019 after identifying substantive
                and procedural errors with respect to numerous provisions, including
                the rule's distance limitations. Georgia v. Wheeler, 2019 WL 3949922,
                at *12-32. By contrast, for the reasons discussed elsewhere in this
                section and in Section III of this notice, this final rule remains
                within the bounds of the agencies' authority under the Constitution and
                the CWA, is properly supported by the record in this rulemaking, and is
                a logical outgrowth of the NPRM.
                 Finally, the agencies believe that this final rule will be clearer
                than the pre-existing regulatory regime restored by the regulatory text
                of the 2019 Rule and the prior implementation of that regime in
                response to adverse Supreme Court decisions and agency guidance. For
                the reasons discussed in the 2019 Rule preamble, that regulatory regime
                is preferable to the 2015 Rule; however, a clear, comprehensive
                regulation that encompasses the Supreme Court's interpretations is
                preferable to the pre-existing regulatory regime restored by the 2019
                Rule. The language of the 2019 Rule regulatory text leaves
                substantially more room for discretion and case-by-case variation than
                does this final rule, particularly paragraph (a)(3) in the 2019 Rule,
                which claims jurisdiction over waters that are used by interstate or
                foreign travelers for recreational or other purposes, with no reference
                to navigable waters. Following the Supreme Court's opinions on the
                definition of ``waters of the United States,'' particularly SWANCC and
                Rapanos, the 2019 Rule must be implemented taking into account the
                Court's holdings and agency guidance interpreting those cases. In the
                decade since the Rapanos decision, the agencies and the public have
                become familiar with this multi-layered interpretive approach, which is
                in part why the agencies finalized the 2019 Rule to maintain the pre-
                existing regime during the process of developing and considering public
                comments on this final rule. The regulatory definition of ``waters of
                the United States'' set forth in this final rule reflects Supreme Court
                case law and clearly establishes the scope of jurisdictional waters
                under the CWA. It provides greater regulatory predictability than the
                regulatory regime restored by the 2019 Rule.
                 In sum, as compared with both the 2015 Rule and the regulatory
                regime restored by the 2019 Rule, this final rule more appropriately
                reflects the scope of the agencies' authority under the statute and the
                Constitution; respects the vital role of the States and Tribes in
                managing their land and water resources; and addresses the need of the
                public for predictable, more easily implementable regulations that aim
                to accomplish the objective of the Act, ``to restore and maintain the
                chemical, physical, and biological integrity of the Nation's waters.''
                33 U.S.C. 1251(a).
                G. Existing Guidance
                 In several places in the preamble to the proposed rule, the
                agencies solicited comment on whether they should revoke the 2003
                SWANCC Guidance or the 2008 Rapanos Guidance if the agencies were to
                finalize the proposal. 84 FR 4165, 4167. These guidance documents were
                drafted to inform the agencies' implementation of the 1986 and 1988
                regulations, which the 2019 Rule recodified, in a manner consistent
                with the Supreme Court's decisions in SWANCC and Rapanos. Some
                commenters thought that the 2003 and 2008 guidance documents provided
                helpful information and assistance to the public in understanding how
                the agencies might implement a definition of ``waters of the United
                States.'' Other commenters thought that the documents should be
                rescinded to avoid confusion during implementation of this final rule,
                particularly because the agencies have totally restructured the
                regulatory definitions. The agencies considered these comments and
                conclude that, when this final rule becomes effective, these and other
                related agency guidance documents, memoranda, and materials will be
                rendered inoperative because they will no longer be necessary or
                material, and they may in fact create confusion as the agencies
                implement this final rule. The agencies can develop new guidance to
                facilitate implementation of this final rule should questions arise, if
                any, regarding the application of the rule to specific
                circumstances.\34\
                ---------------------------------------------------------------------------
                 \34\ To the extent that, as a result of litigation, the 1986 and
                1988 regulations, which the 2019 Rule recodified, remain or become
                legally effective after the effective date of this rule as a result
                of litigation, the agencies intend to use the guidance documents
                relevant to those regulations, including the 2003 SWANCC Guidance
                and 2008 Rapanos Guidance, if necessary to inform implementation of
                those regulations.
                ---------------------------------------------------------------------------
                [[Page 22273]]
                III. Definition of ``Waters of the United States''
                 The following is a summary of the key elements and each substantive
                provision of this final rule. Each subsection describes what the
                agencies are finalizing, why the agencies are finalizing the regulatory
                text, and how the agencies plan to implement the final rule. To assist
                the reader, the longer subsections have internal headings.
                 In this final rule the agencies interpret the term ``the waters''
                in the phrase ``the waters of the United States'' to encompass
                relatively permanent flowing and standing waterbodies that are
                traditional navigable waters in their own right or that have a specific
                surface water connection to traditional navigable waters, as well as
                wetlands that abut or are otherwise inseparably bound up with such
                relatively permanent waters. As the plurality decision in Rapanos
                notes, the term ``the waters'' is most commonly understood to refer to
                ``streams and bodies forming geographical features such as oceans,
                rivers, lakes,'' or ``the flowing or moving masses, as of waves or
                floods, making up such streams or bodies.'' 547 U.S. at 732 (citing
                Webster's New International Dictionary 2882 (2d ed. 1954)); see also
                Riverside Bayview, 474 U.S. at 131 (characterizing ``waters of the
                United States'' as including ``rivers, streams, and other hydrographic
                features more conventionally identifiable as `waters' ''); see also 118
                Cong. Rec. 33699 (Oct. 4, 1972) (statement of Sen. Muskie) (referring
                to ``navigable waters'' as ``water bodies''). According to the Rapanos
                plurality, however, the ordinary meaning of the term ``waters'' does
                not include areas that are dry most of the year, and which may
                occasionally contain ``transitory puddles or ephemeral flows of
                water.'' 547 U.S. at 733.
                 The agencies received considerable public comments on the scope of
                the proposed definition of ``waters of the United States.'' Some
                commenters stated that the proposed rule would include more waters and
                wetlands than appropriate under a strict reading of Justice Scalia's
                plurality opinion in Rapanos and is therefore inconsistent with
                Executive Order 13778. Some commenters agreed with the proposed rule,
                stating that it struck an appropriate balance of asserting jurisdiction
                over waters that should be regulated by the Federal government,
                provided clear direction for the regulated community, and respected
                State and tribal authority over their own land and water resources.
                Some commenters stated that the proposal failed to include ecologically
                important waters and wetlands and failed to give due weight to Justice
                Kennedy's concurring opinion in Rapanos. Other commenters stated that
                the proposed rule and supporting rationale were based exclusively on
                the CWA section 101(b) policy to ensure that States maintain primary
                authority over land and water resources and failed to give due weight
                to the objective in CWA section 101(a) to restore and maintain the
                chemical, physical, and biological integrity of the nation's waters.
                 The agencies disagree with commenters' suggestion that the
                Executive Order requires the agencies to rely exclusively on Justice
                Scalia's opinion in Rapanos. The Executive Order requires the agencies
                to consider that opinion, which is what the agencies have done here.
                The agencies also disagree with commenters' suggestion that the
                proposal failed to incorporate principles from Justice Kennedy's
                opinion, and further disagree with commenters' suggestion that the
                agencies failed to consider the objective of section 101(a) in
                determining where to draw the line of federal jurisdiction. However,
                the agencies considered these and other public comments, and have made
                modifications in the final rule to better incorporate common principles
                of the Rapanos plurality and concurring opinions, and to strike a
                careful balance between the clear directive from Congress to ensure
                that States maintain primary authority over land and water resources,
                and the importance of maintaining federal authority over those waters
                that Congress determined should be regulated by the Federal government
                under its Commerce Clause powers.
                 The final definition of ``waters of the United States'' aligns with
                the intent of Congress to interpret the term ``navigable waters''
                beyond just commercially navigable-in-fact waters. This definition
                recognizes Congress' intent ``to exercise its powers under the Commerce
                Clause to regulate at least some waters that would not be deemed
                `navigable' under the classical understanding of that term,'' Riverside
                Bayview, 474 U.S. at 133, but at the same time acknowledges that
                ``[t]he grant of authority to Congress under the Commerce Clause,
                though broad, is not unlimited.'' SWANCC, 531 U.S. at 173. The
                definition also recognizes the constitutional underpinning of the CWA,
                which was Congress' exercise of ``its commerce power over navigation.''
                Id. at 168 n.3.
                 This final rule establishes categorical bright lines to improve
                clarity and predictability for regulators and the regulated community
                by defining ``waters of the United States'' to include the following
                four categories: (1) The territorial seas and traditional navigable
                waters; (2) tributaries of such waters; (3) certain lakes, ponds, and
                impoundments of jurisdictional waters; and (4) wetlands adjacent to
                other jurisdictional waters (other than waters that are themselves
                wetlands). The final rule eliminates the case-specific application of
                the agencies' previous interpretation of Justice Kennedy's significant
                nexus test in the Rapanos Guidance, and instead establishes clear
                categories of jurisdictional waters that adhere to the basic principles
                articulated in the Riverside Bayview, SWANCC, and Rapanos decisions
                while respecting the overall structure and function of the CWA.
                A. Key Terms and Concepts
                 Each of the four categories of waters of the United States
                established by this final rule, as well as the waters that fall beyond
                CWA jurisdiction, is discussed in detail in Sections III.B through
                III.H below. Many of the operative terms used in the final rule are
                defined in paragraph (c), and their applicability is discussed at
                length throughout those subsections. This subsection summarizes a few
                key terms and concepts that help inform the overall implementation of
                the jurisdictional categories established by paragraph (a) and the non-
                jurisdictional waters established by paragraph (b), and are highlighted
                here for ease of reference and additional clarity.
                 One such term is ``typical year.'' As discussed above, the meaning
                of the phrase ``waters of the United States'' has been mired in
                confusion for decades. This is in part because courts, regulators, the
                regulated community, and members of the public have lacked clear
                guidance as to how far up the watershed federal jurisdiction extends,
                and what connection is required for waters to be considered part of the
                regulated tributary system to traditional navigable waters and the
                territorial seas. The last two Supreme Court cases on point--SWANCC and
                Rapanos--provided clear instruction to the agencies that their prior
                interpretations had exceeded their jurisdictional authority under the
                CWA. The phrase ``typical year'' as used in the final rule and
                throughout this notice is intended to provide a predictable framework
                in
                [[Page 22274]]
                which to establish federal jurisdiction over relatively permanent
                waters that contribute surface water flow to waters identified in
                paragraph (a)(1) (generally referred to as ``paragraph (a)(1) waters''
                or ``a paragraph (a)(1) water'' in this notice), and wetlands adjacent
                to such waters. The term ``typical year'' is summarized in Section
                III.A.1 and is further discussed throughout the notice.
                 The agencies are also defining the terms ``perennial,''
                ``intermittent,'' and ``ephemeral'' in the final rule, adding clarity
                and certainty for how these frequently used terms apply in the ``waters
                of the United States'' context. The agencies have used these terms to
                assess jurisdictional status under the CWA, but until this final rule
                have never defined them in the regulatory text. The terms have specific
                meaning in the scientific community, but when used in legal settings,
                common parlance often converges with scientific meaning, creating
                opportunities for misunderstanding. For example, while the Rapanos
                plurality stated that the term ``waters of the United States'' does not
                include ``ordinarily dry channels through which water occasionally or
                intermittently flows,'' 547 U.S. at 733 (emphasis added), it also
                stated the phrase does ``not necessarily exclude seasonal rivers, which
                contain continuous flow during some months of the year but no flow
                during dry months.''). Id. at 732 n.5 (emphasis in original).
                ``Seasonal rivers''--which the plurality would not categorically
                exclude--are known among scientists as ``intermittent streams''--which
                the plurality stated it would exclude. The plurality also appears to
                confuse the scientific understanding of the terms `` `intermittent' and
                `ephemeral' streams,'' conflating them to mean ``streams whose flow is
                . . . `existing only, or no longer than, a day[.]' '' Id. Indeed, this
                description more accurately captures the hydrological definition of
                ``ephemeral streams'' which only flow during or in immediate response
                to rainfall. By contrast, ``intermittent streams'' typically flow for a
                more continuous period like the ``seasonal rivers'' the plurality
                describes. Because the definition of ``tributary'' specifically uses
                and relies on the terms ``perennial'' and ``intermittent,'' but not
                ``ephemeral,'' the agencies are clearly defining these terms in the
                final rule. These terms are summarized below in Section III.A.2 and are
                further discussed throughout the preamble.
                 Another challenging issue that has confounded the meaning of
                ``waters of the United States'' for years is what types of natural or
                artificial features potentially sever jurisdiction between the upstream
                and downstream portions of a waterway. For example, if the waters of a
                perennial headwater stream are diverted to another basin for
                consumptive use and the downstream reach runs dry for major portions of
                a year, or the flow of a stream disappears into the desert floor before
                reaching a traditional navigable water, questions are frequently raised
                regarding the jurisdictional status of those waters. Subsection III.A.3
                below discusses the ``breaks'' topic in detail and how the agencies
                have addressed the various artificial and natural features that either
                maintain or sever jurisdiction under the final rule.
                1. Typical Year
                 In this final rule, the agencies use the term ``typical year'' to
                help establish the surface water connection between a relatively
                permanent body of water and traditional navigable waters, and between
                certain wetlands and other jurisdictional waters, that is sufficient to
                warrant federal jurisdiction. ``Typical year'' is defined in the final
                rule to mean when precipitation and other climatic variables are within
                the normal periodic range (e.g., seasonally, annually) for the
                geographic area of the applicable aquatic resource based on a rolling
                thirty-year period. Under this final definition, a typical year would
                generally not include times of drought or extreme flooding. In other
                words, the purpose of the term is to ensure that flow characteristics
                are not assessed under conditions that are too wet or are too dry. As
                discussed in Section III.G.2, climatic conditions, including flow or
                flooding, that may occur under ``typical year'' conditions do not
                necessarily occur in every calendar year.
                 The agencies proposed to use the term ``typical year'' to mean
                within the normal range of precipitation over a rolling thirty-year
                period for a particular geographic area; that is, during times when it
                is not too wet and not too dry. However, some commenters on the
                proposed rule expressed confusion about the proposed ``typical year''
                definition, including how it is calculated and what timeframe it
                represents. Commenters also expressed concern that the proposed
                definition included only precipitation as a driver of streamflow
                classification. Other commenters supported the typical year concept as
                proposed. In response to these comments, the agencies have modified the
                definition of ``typical year'' to expressly include other climatic
                variables in addition to precipitation and additional description of
                the normal periodic range, signaling that such range need not be based
                on a calendar year. The agencies believe the revised definition more
                appropriately reflects what the agencies intended to measure, which is,
                simply put, the characteristics of a waterbody at times that are not
                too wet and not too dry.
                 To determine whether water features are being assessed during
                normal precipitation conditions, the agencies currently use data from
                the National Oceanic and Atmospheric Administration's (NOAA) Global
                Historic Climatology Network, which integrates climate data from over
                20 sources. The agencies evaluate normal precipitation conditions based
                on the three 30-day periods preceding the observation date. For each
                period, a weighted condition value is assigned by determining whether
                the 30-day precipitation total falls within, above, or below the 70th
                and 30th percentiles for totals from the same date range over the
                preceding 30 years. The agencies make a determination of ``normal,''
                ``wetter than normal,'' or ``drier than normal'' based on the condition
                value sum. While the agencies will generally use this method to
                implement this final rule, the agencies also recognize there may be
                other accurate and reliable measurements of normal precipitation
                conditions and will make adjustments to the approach as is
                scientifically warranted. The agencies may also consider alternative
                methods that are developed and appropriately validated, including
                different statistical percentiles, evaluation periods, or weighting
                approaches for condition values.
                 Some commenters on the proposed rule were concerned that a 30-year
                period may be too long or too short of a record, or that rolling 30-
                year climate percentiles would be difficult to calculate. The agencies
                have concluded that a rolling 30-year period would account for
                variability to provide a reliable indicator of the climate in a given
                geographic area without being confounded by a year or two of unusual
                climate data. A standard timeframe is necessary to ensure consistent
                application across the country, and 30 years is the most common and
                recognized timeframe utilized in other government climatic data
                programs (e.g., NOAA's National Climatic Data Center climate normals,
                which are based on World Meteorological Organization requirements).
                Nearly a century ago, the International Meteorological Organization,
                now known as the World Metrological Organization, instructed member
                nations to calculate climate normals using 30-year periods, beginning
                with 1901 to 1930 (see https://www.ncdc.noaa.gov/news/
                [[Page 22275]]
                defining-climate-normals-new-ways). Recognizing that precipitation and
                temperature change over time, the agencies have determined that a
                rolling 30-year record is necessary to ensure that changing conditions
                are captured by the calculation. The agencies have considered other
                alternative time periods and are maintaining the well-established 30-
                year period.
                 The agencies proposed that the geographic area be on a watershed-
                scale basis to ensure specific climatic data are representative of the
                landscape in relation to the feature under consideration for meeting
                the ``tributary'' definition and sought comment on the appropriate
                watershed scale. Some commenters on the proposed rule suggested
                constraining precipitation data sources to the smallest practicable
                watershed scale (e.g., a USGS HUC-12 scale). However, other commenters
                noted that 30 years of data may not always be available at that scale,
                and other considerations such as distance or ecoregion are also
                important for identifying appropriate climatic data. In response to
                these comments, the agencies have determined that specifying a
                particular watershed size or Hydrologic Unit Code (HUC) could preclude
                the use of the best available data sources, but that watershed
                boundaries should be a consideration when selecting climate records.
                Other considerations should include data availability, topography, and
                distance of climatic data collection in relation to the aquatic
                resource location.
                 The agencies recognize that precipitation data may not be the only
                appropriate indicator for determining ``typical year,'' as was noted by
                many commenters on the proposed rule. Although the agencies will
                generally use the methodology described in this notice for determining
                normal precipitation conditions, the agencies will consider and use the
                best available data and information, which provides the most accurate
                and reliable representative information for the aquatic resource in
                question, to determine ``typical year.'' For instance, determinations
                of ``typical year'' based on precipitation totals may conflict with
                other sources of information such as drought indices, which account for
                other hydrologic factors like evapotranspiration and water storage. The
                agencies currently use professional judgment and a weight of evidence
                approach as they consider precipitation normalcy along with other
                available data sources. These data sources include, but are not limited
                to, the Web-based Water-Budget Interactive Modeling Program (WebWIMP)
                for approximate dates of wet and dry seasons for any terrestrial
                location based on average monthly precipitation and estimated
                evapotranspiration (http://climate.geog.udel.edu/~wimp/); Climate
                Analysis for Wetlands Tables (known as WETS tables, or similar tools,
                as the WETS tables are currently in a fixed 30-year timeframe), which
                are provided by the NRCS National Water and Climate Center (https://www.wcc.nrcs.usda.gov/climate/wets_doc.html) and were calculated from
                long-term (30-year) weather records gathered at National Weather
                Service meteorological stations; and drought indices, such as the
                Palmer Drought Severity Index (PDSI) (Sprecher and Warne 2000), where
                time-series plots of PDSI values by month or year are available from
                the National Climatic Data Center (https://www.ncdc.noaa.gov/temp-and-precip/drought/historical-palmers/psi/201811-201910 or https://www.cpc.ncep.noaa.gov/products/monitoring_and_data/drought.shtml).
                2. Perennial, Intermittent, and Ephemeral
                 Though ``perennial,'' ``intermittent,'' and ``ephemeral'' are
                commonly used scientific terms, the agencies are including definitions
                of these terms in the final rule to ensure that the regulation is
                clear. In this final rule, the agencies define the term ``perennial''
                to mean surface water flowing continuously year-round. The term
                ``intermittent'' in the final rule means surface water flowing
                continuously during certain times of the year and more than in direct
                response to precipitation (e.g., seasonally when the groundwater table
                is elevated or when snowpack melts). The phrase ``certain times of the
                year'' is intended to include extended periods of predictable,
                continuous surface flow occurring in the same geographic feature year
                after year. Continuous surface water flow during certain times of the
                year may occur seasonally such as in the spring when evapotranspiration
                is low and the groundwater table is elevated. Under these conditions,
                the groundwater table intersects the channel bed and groundwater
                provides continuous baseflow for weeks or months at a time even when it
                is not raining or has not very recently rained. Melting snowpack can be
                the sole or primary source of perennial or intermittent flow in a
                tributary. The term ``snowpack'' is defined as ``layers of snow that
                accumulate over extended periods of time in certain geographic regions
                or at high elevation (e.g., in northern climes or mountainous
                regions).'' Perennial or intermittent flow in certain mountain streams,
                for example, may result primarily from melting snowpack, not from
                groundwater contributions to the channel. The term ``ephemeral'' in the
                final rule means surface water flowing or pooling only in direct
                response to precipitation, such as rain or snow fall. With these
                definitions, the agencies distinguish ephemeral flow resulting from a
                snow fall event from sustained intermittent flow resulting from melting
                snowpack that is continuous, such as for weeks or months at a time.
                 Some commenters requested that the final rule require that
                groundwater must be the source for perennial and intermittent flow in
                tributaries. The agencies recognize that groundwater input is an
                element of most scientific definitions of perennial and intermittent
                flow,\35\ but have decided not to mandate groundwater input as part of
                the definition of ``perennial'' or ``intermittent'' in the final rule.
                As a threshold matter, the agencies believe that such an approach would
                too narrowly limit CWA jurisdiction over waters that provide continuous
                or intermittent and predictable flow to traditional navigable waters in
                a typical year. For example, many headwater streams in mountainous
                regions flow through channels incised in bedrock with no groundwater
                interface with the bed of the stream. These streams instead are fed by
                glacial or high elevation snowpack melt. The same scenario may also
                exist in northern climes, where spring flows could be fed almost
                exclusively through melting snowpack absent elevated groundwater
                tables. Mandating a groundwater interface and contribution of flow
                could also be challenging to implement, as identifying whether the
                channel bed intersects the groundwater table may be difficult to
                accomplish in the field, gathering the relevant data could be time
                consuming, and implementing a source water-based definition could
                require new tools and training of field staff and the regulated public.
                The requirement for a groundwater flow source could also render
                effluent-dependent streams non-jurisdictional. The agencies do not
                interpret the text or legislative history of the CWA or Supreme Court
                guidance to mandate groundwater input as a condition precedent for
                asserting jurisdiction over tributaries to traditional navigable
                waters.
                ---------------------------------------------------------------------------
                 \35\ See, e.g., 82 FR 2006 (Jan. 6, 2017) (Corps nationwide
                permit program); National Research Council. 2002. Riparian Areas:
                Functions and Strategies for Management. Washington, DC: The
                National Academies Press. https://doi.org/10.17226/10327.
                ---------------------------------------------------------------------------
                 A few commenters asked for clarification to better distinguish
                [[Page 22276]]
                between flow ``in direct response to precipitation'' versus ``more than
                in direct response to precipitation,'' as well as further clarification
                on the distinction between ephemeral and intermittent flow
                classifications in general. For example, they requested clarification
                on whether streams that flow continuously during a rainy season (e.g.,
                monsoon-driven streams in the arid West) are considered intermittent.
                The use of the term ``direct'' by the agencies in the proposed rule and
                maintained in this final rule is intended to distinguish between flow
                solely caused by individual precipitation events (including multiple,
                individual back-to-back storms), and continuous flow resulting, for
                example, from weeks- or months-long accumulation of precipitation in
                the form of snowpack that melts slowly over time or an elevated
                groundwater table that provides baseflow to the channel bed.
                 Ephemeral flow may occur simply because it is raining or has very
                recently rained or it has recently snowed and the snow has melted. For
                example, ephemeral flow could be the result of a small, brief storm
                event, one long storm event producing rainfall for several days without
                pause, or several back-to-back storms. Continuous flow occurring more
                than in direct response to precipitation could include ``seasonal''
                flow, such as when snowpack melts or when groundwater is elevated and
                provides baseflow to the channel bed. Streamflow that occurs during the
                monsoon season in certain parts of the country (typically June through
                September in the arid West) may be ephemeral or intermittent, with the
                distinction made according to the definition of each term in the final
                rule. For example, a stream in the arid West is ephemeral if it flows
                only in direct response to rainfall, even if the flow may appear
                relatively continuous as a result of multiple, individual storms during
                the monsoon season. On the other hand, when monsoon floodwaters locally
                recharge the riparian aquifer through bank infiltration and supply
                sustained baseflow to streams in the arid West when it is not raining
                or has not recently rained, such streams meet the rule's definition of
                ``intermittent'' if they flow seasonally, for example, or ``perennial''
                if they flow continuously year-round.\36\
                ---------------------------------------------------------------------------
                 \36\ See e.g., Baillie, M.N., J.F. Hogan, B. Ekwurzel, A.K.
                Wahi, and C.J. Eastoe. 2007. Quantifying water sources to a semiarid
                riparian ecosystem, San Pedro River, Arizona, J. Geophysical Res.,
                112, GO3S02, doi: 10.1029/2006JG000263. Ballie et al. (2007) found
                that locally recharged monsoon floodwater is one of the dominant
                water sources in the main stem of the spatially intermittent San
                Pedro River in Arizona. The authors also define ``monsoon storms''
                as ``short, intense rainstorms that generate significant amounts of
                flooding and ephemeral flow (i.e., flow in ephemeral channels on the
                basin floor) and represent, on average, the bulk of summer
                moisture.'' (Emphasis added). See also Connectivity Report at B-39
                (``Monsoon-generated, short-duration runoff dominates the San Pedro
                watershed. . . Most perennial and intermittent rivers in the
                Southwest are groundwater dependent, flowing primarily in a baseflow
                regime and supported by discharge from a connected regional or
                alluvial aquifer or both. . . . [P]art of the baseflow is often
                sustained or augmented by slow drainage of a shallow alluvial
                aquifer from past flooding.'')
                ---------------------------------------------------------------------------
                 Some commenters requested clarity on the specific geographic
                regions where ``snowpack'' as defined under the proposed rule would
                occur. Other commenters requested that the agencies clarify how melting
                snowpack is distinguished from melting snowfall and clearly articulate
                the amount of snow needed to meet the definition of ``snowpack,'' as
                well as provide clarity on what ``extended periods'' of time means.
                They also requested clarification on the sources of information (e.g.,
                from NOAA, NRCS, or another source) that can be used to identify
                ``snowpack.'' ``Extended periods of time'' refers to more than merely a
                single snowfall event or periodic events with repeated snowmelts after
                each occurrence, but rather recurring snow events which result in an
                accumulation of multiple layers of snow in certain geographic regions,
                which may include, for example, parts of North Dakota or Alaska, or at
                high elevation, to potentially include the Rocky, Sierra Nevada, or
                Cascade mountains. A foot of new snow fall on the high plains of
                southern Wyoming in May will typically melt quickly under the intense
                sun of subsequent days, while a foot of snow in northern Wisconsin in
                January will likely contribute to seasonal snowpack that may not melt
                until spring thaw. The first scenario is more likely to cause ephemeral
                flow, the second is more likely to cause intermittent flow. The
                agencies could consider any data sources that provide an accurate
                estimation of ``snowpack'' in identifying that feature. The agencies
                are not limiting the identification of snowpack to one data source,
                such as those provided by NOAA or NRCS, although those are reliable
                existing sources to find information on snowpack. The Bureau of
                Reclamation and several western States depend on accurate snow fall and
                accumulation data to project water availability for consumptive needs
                and the allocation of water rights. Analyzing the location and
                seasonality of snowpack is a common, well understood practice in other
                contexts and will not pose implementation challenges to the agencies
                under the final rule as they draw on the expertise of other Federal and
                State partners.
                 In certain parts of the country and during certain times of the
                year, snowpack may have a more significant influence on flow
                classifications than rainfall. Sources of information on ``snowpack''
                can be found in the NOAA national snow analyses maps (https://www.nohrsc.noaa.gov/nsa/), in NRCS sources (https://www.wcc.nrcs.usda.gov/snow/), or by using hydrographs of subject
                locations as a potential guide to alert the regulated public and
                regulators as to which regions of the country have to consider snowpack
                scenarios. In these regions, for example, a hydrograph could indicate a
                large increase in discharge volume due to the late spring/early summer
                thaws of melting snowpack. These are indicators of a regular,
                predictable, seasonal occurrence of flow. The large water contribution
                source for those northern geographic regions which do not have
                significant elevation changes, but which do have a consistent,
                predictable snowfall that accumulates on the ground for extended
                periods of time, are covered in this rule's definition of ``snowpack''
                in paragraph (c)(10), in addition to mountainous regions with snowpack.
                3. Breaks
                 Under the proposed rule, an artificial or natural ephemeral feature
                (e.g., an ordinarily dry channel only flowing during or in immediate
                response to precipitation) occurring in a typical year at any point
                along a tributary network would have severed jurisdiction upstream of
                the ``break'' because the waterbody would not convey surface water to a
                paragraph (a)(1) water year-round or continuously for extended periods
                of time. 84 FR 4173-74. To be jurisdictional, lakes and ponds that are
                not paragraph (a)(1) waters would have needed to maintain perennial or
                intermittent flow to a paragraph (a)(1) water in a typical year or be
                flooded by a jurisdictional water in a typical year. Id. at 4182. In
                other words, to be jurisdictional, the proposed rule would have
                required tributaries and most lakes and ponds to maintain a perennial
                or intermittent surface water connection all the way to a downstream
                paragraph (a)(1) water. The agencies received public comments
                indicating that this approach could affect the jurisdictional status of
                many waters, particularly in the arid West; that it could inadvertently
                subject otherwise exempt water transfers to CWA section 402 permitting;
                and it could create
                [[Page 22277]]
                implementation challenges. The agencies received other comments
                supporting the proposed approach.
                 As further discussed below, the final rule contains some important
                changes to address these concerns, which are intended to better
                incorporate common principles from the Rapanos plurality and concurring
                opinions, and to strike a better balance between the objective and
                policy in CWA sections 101(a) and 101(b), respectively. Changes made in
                the final rule, however, remain faithful to the overall text,
                structure, and legislative history of the CWA and the legal principles
                outlined in Section II.E. Many of the changes were designed to address
                questions and concerns regarding under what circumstances a natural or
                artificial feature severed upstream jurisdiction, as discussed in
                detail in this subsection and as further explained throughout Section
                III.
                 The Supreme Court has not spoken directly to the question of
                whether a non-jurisdictional ephemeral break along or downstream of an
                otherwise jurisdictional tributary, lake, pond, or impoundment would
                sever jurisdiction of upstream waters. As described in Section II.E,
                Supreme Court precedent provides some insight regarding CWA
                jurisdiction of relatively permanent bodies of water, including
                tributaries, lakes, and ponds, and their connection to traditional
                navigable waters, but it does not provide comprehensive guidance. For
                example, the Rapanos plurality describes a ``water of the United
                States'' as ``a relatively permanent body of water connected to
                traditional interstate navigable waters[.]'' Rapanos, 547 U.S. at 742
                (emphasis added). Regarding the connection between a water in question
                and downstream navigable waters, Justice Kennedy noted that ``in some
                instances, as exemplified by Riverside Bayview, the connection between
                a nonnavigable water . . . and a navigable water may be so close, or
                potentially so close, that the Corps may deem the water . . . a
                `navigable water' under the Act. In other instances, as exemplified by
                SWANCC, there may be little or no connection.'' Id. at. 767. Justice
                Kennedy also stated that ``mere hydrologic connection should not
                suffice in all cases; the connection may be too insubstantial for the
                hydrologic linkage to establish the required nexus with navigable
                waters as traditionally understood.'' Id. at 784-85.
                 Although the Rapanos plurality opinion did not specify what would
                constitute a sufficient connection between relatively permanent waters
                and downstream traditional navigable waters, it did signal types of
                connections that are likely insufficient to maintain jurisdiction when
                read in context with the principles articulated throughout the balance
                of the opinion. For instance, the plurality characterized an
                ``expansive definition of `tributaries' '' as including ``dry arroyos
                connected to remote waters through the flow of groundwater over
                `centuries,' '' id. at 725-26 (internal citations omitted), and
                described federal control over ``irrigation ditches and drains that
                intermittently connect to covered waters'' as ``sweeping assertions of
                jurisdiction.'' Id. at 726-27. In addition to ``tributaries,'' the
                plurality noted with disapproval that the Corps and lower courts had
                ``define[d] `adjacent' wetlands broadly'' to include wetlands
                ``hydrologically connected'' ``to covered waters'' `` `through
                directional sheet flow during storm events,' '' and wetlands
                ``connected to the navigable water by flooding, on average, once every
                100 years[.]'' Id. at 728. The agencies considered these observations
                in developing the final rule but recognize that the Supreme Court has
                not spoken directly to every aspect of the agencies' existing
                regulations or every fact pattern that may raise questions of federal
                jurisdiction. The final rule therefore is also based on the text,
                structure, and legislative history of the CWA, the reasoned policy
                choices of the executive branch agencies authorized by Congress to
                implement the Act, and the agencies' technical and scientific expertise
                administering the CWA over nearly five decades.
                 The proposed rule, which would have severed jurisdiction upstream
                of any ephemeral feature, reflected a reasonable interpretation of the
                CWA and incorporated relevant Supreme Court guidance. However, upon
                further consideration, the agencies conclude that the proposed rule's
                treatment of ephemeral features would have severed jurisdiction for
                certain relatively permanent bodies of water that are regularly
                ``connected to'' traditional navigable waters via channelized surface
                water flow, allowing such waters to connect and become
                indistinguishable when flowing. Some ephemeral reaches between upstream
                and downstream relatively permanent (i.e., perennial or intermittent)
                waters convey surface water from the upstream water to the downstream
                covered water during a typical year. These reaches allow upstream
                relatively permanent jurisdictional waters to have a surface water
                connection to downstream jurisdictional waters in a typical year when
                there is sufficient water in the system. In contrast, other ephemeral
                streams, including those at the very headwaters of a channel network,
                do not connect relatively permanent jurisdictional waters to downstream
                jurisdictional waters; rather, they are merely ``channels that
                periodically provide drainage for rainfall.'' Rapanos, 547 U.S at 739
                (Scalia, J. plurality). The agencies conclude in this final rule that
                certain ephemeral features between upstream relatively permanent
                jurisdictional waters and downstream jurisdictional waters do not sever
                jurisdiction upstream so long as such features satisfy the conditions
                described further below. Like the proposed treatment of ephemeral
                features, the final rule is based on an equally reasonable
                interpretation of the CWA and Supreme Court precedent, and
                appropriately balances the plurality and concurring opinions in Rapanos
                and the objective of the Act and the policy of Congress set forth in
                CWA sections 101(a) and 101(b).
                 In the final rule, certain ephemeral features do not sever
                jurisdiction of an upstream relatively permanent jurisdictional water
                so long as they provide a surface water connection to a downstream
                jurisdictional water in a typical year. Specifically, the final rule
                provides that a tributary does not lose its jurisdictional status if it
                contributes surface water flow in a typical year to a downstream
                jurisdictional water through a channelized non-jurisdictional surface
                water feature, through a subterranean river, through a culvert, dam,
                tunnel, or similar artificial feature, or through a debris pile,
                boulder field, or similar natural feature. See paragraph (c)(12). The
                final rule applies the same basic principles to the category of lakes,
                ponds, and impoundments of jurisdictional waters. See paragraph (c)(6).
                A lake, pond, or impoundment of a jurisdictional water does not lose
                its jurisdictional status if it contributes surface water flow to a
                downstream jurisdictional water in a typical year through artificial
                features such as culverts and spillways. The agencies conclude that
                such features do not necessarily sever jurisdiction of upstream waters.
                However, if an artificial feature does not allow for the contribution
                of surface water flow to a downstream jurisdictional water in a typical
                year, it severs jurisdiction upstream of the artificial feature. The
                final rule treats natural features such as debris piles and boulder
                fields the same way that it treats the artificial features described
                above.
                 The changes made in the final rule address concerns raised by
                commenters about features that would sever the jurisdiction of upstream
                portions of the
                [[Page 22278]]
                tributary network, including relatively permanent upstream waters that
                contribute surface water flow to downstream waters when enough water is
                in the system. It also addresses concerns raised by water management
                interests that suggested the proposed rule could have inadvertently
                undermined the NPDES permitting exemption authorized by the EPA's Water
                Transfers Rule, 73 FR 33697 (June 13, 2008). That rule does not require
                NDPES permits for water transfers between waters of the United States
                because they do not result in the ``addition'' of a pollutant. Id. at
                33699. In many regions of the country, particularly the arid West,
                inter- and intra-basin water transfers may originate in perennial or
                intermittent waters that may be disconnected from downstream waters by
                ephemeral breaks. In many circumstances, those ephemeral breaks may be
                caused by water management systems, including through water transfers,
                water storage reservoirs, flood irrigation channels, and similar
                structures. Not all diversions will cause a downstream portion of an
                otherwise perennial or intermittent stream to become ephemeral in a
                typical year; however, the modifications made by the final rule to the
                categories of tributaries and of lakes, ponds, and impoundments of
                jurisdictional waters help address the concerns raised by commenters
                regarding the potential impact of the proposed rule on longstanding
                water management practices in this country. The agencies are cognizant
                of the importance of water management in the States and the explicit
                policy directives of Congress to recognize the authority of States to
                allocate and manage water resources within their respective
                jurisdictions. See 33 U.S.C. 1251(g), 1370.
                 Under the final rule, ephemeral features and other excluded
                artificial and natural features are not jurisdictional and do not
                become jurisdictional even if they episodically convey surface water
                from upstream relatively permanent jurisdictional waters to downstream
                jurisdictional waters in a typical year, and thereby help maintain the
                jurisdictional status of the upstream waters. This approach
                incorporates the plurality's requirement that jurisdictional waters be
                continuously present, fixed bodies of water and that dry channels,
                transitory puddles, and ephemeral flows be excluded from jurisdiction.
                547 U.S. at 733-34; see also id. at 731 (``[T]he CWA authorizes federal
                jurisdiction only over `waters.' 33 U. S. C. 1362(7).''). This approach
                also requires a regular and predictable surface water connection--one
                that occurs in a typical year--which addresses Justice Kennedy's
                concern that speculative and insubstantial connections may not be
                sufficient to establish jurisdiction. Id. at 784-86. The types of
                connections that maintain jurisdiction between relatively permanent
                bodies of water are described more fully below.
                 The agencies conclude that tributaries, lakes, ponds, and
                impoundments of jurisdictional waters that are relatively permanent
                flowing or standing waterbodies upstream of certain excluded features
                are jurisdictional so long as the non-jurisdictional feature maintains
                a channelized surface water connection to downstream jurisdictional
                waters in a typical year. Paragraph (b) of the final regulation
                identifies twelve categories of excluded features, but only those
                features that convey channelized surface flow between upstream
                relatively permanent waters and downstream jurisdictional waters in a
                typical year can maintain jurisdiction of the upstream waters. For
                example, non-jurisdictional ditches could be capable of conveying
                channelized surface water flow between upstream relatively permanent
                jurisdictional waters and downstream jurisdictional waters in a typical
                year. Similarly, a surface water connection may occur through an
                ephemeral channelized conveyance and may result in the mixing of
                upstream and downstream relatively permanent waters following
                sufficient precipitation, but in all cases such a connection must occur
                in a typical year.
                 The final rule also provides that other types of artificial or
                natural features, such as dams or boulder fields, may maintain
                jurisdiction so long as they convey surface water flow from an upstream
                tributary, lake, pond or impoundment of a jurisdictional water to a
                downstream jurisdictional water in a typical year. The agencies have
                concluded that water flowing through features such as dams or boulder
                fields can sustain a regular and predictable surface connection between
                upstream and downstream waters and therefore can maintain jurisdiction
                between such waters.
                 By contrast, diffuse stormwater runoff and directional sheet flow
                by their very nature do not convey channelized surface flow and do not
                provide regular and predictable surface water connections between
                upstream relatively permanent bodies of water and downstream
                jurisdictional waters. Unchannelized surface flow, such as diffuse
                runoff or overland sheet flow, lacks an adequate physical indicator of
                regular surface flow and can be ubiquitous across the landscape,
                occurring over parking lots and lawns, for example. As Justice Kennedy
                notes in Rapanos, ``mere hydrologic connection should not suffice in
                all cases[,]'' 547 U.S. at 784, and the agencies agree with the Rapanos
                plurality that ``[t]he plain language of the statute simply does not
                authorize [a] `Land is Waters' approach to federal jurisdiction.'' Id.
                at 734. The agencies ``must necessarily choose some point at which
                water ends and land begins[,]'' Riverside Bayview, 474 U.S. at 132, and
                conclude that diffuse runoff and overland sheet flow connections are
                ``too insubstantial for the hydrologic linkage to establish the
                required nexus with navigable waters as traditionally understood.''
                Rapanos, 547 U.S. at 784-85 (Kennedy, J. concurring in the judgment).
                In this final rule, the agencies therefore conclude that surface water
                flowing as unchannelized runoff or sheet flow over land cannot sustain
                a regular or predictable surface water connection between upstream and
                downstream waters and therefore cannot maintain jurisdiction between
                such waters. By contrast, channelized ephemeral features may indicate
                that surface water predictably moves from upstream relatively permanent
                waters to downstream jurisdictional waters, such that they may be
                capable of providing a surface water connection sufficient to warrant
                federal regulation over the upstream water. As noted above, a non-
                jurisdictional feature remains non-jurisdictional even if it provides a
                channelized surface water connection between jurisdictional waters in a
                typical year.
                 Like diffuse overland flow, the agencies also conclude that
                relatively permanent bodies of water that are connected to downstream
                jurisdictional waters only via groundwater are not jurisdictional and
                are more appropriately regulated by the States and Tribes under their
                sovereign authorities. The agencies have long interpreted the CWA as
                not authorizing jurisdiction over groundwater and have historically
                excluded groundwater from the definition of ``waters of the United
                States.'' The agencies are retaining that longstanding principle in
                this final rule. See paragraph (b)(2). If groundwater is not
                jurisdictional, it also makes practical sense that surface water
                features connected only via groundwater likewise are not
                jurisdictional. See Rapanos, 547 U.S. at 725-26 (Scalia, J., plurality)
                (identifying groundwater connections as an example of the expansive
                interpretation of
                [[Page 22279]]
                tributaries under the Act). The term ``navigable'' as used in the
                statute must be given some meaning, see SWANCC, 531 U.S. at 172, and
                regulating surface waters with no surface water connection to
                traditionally navigable waters stretches that meaning ``beyond
                parody.'' Rapanos, 547 U.S. at 734 (Scalia, J., plurality). There are,
                however, certain unique subsurface connections that could maintain
                jurisdiction as discussed below; the agencies recognize that there are
                some relatively permanent tributaries that are relocated below ground
                to allow reasonable development to occur.
                 In urban areas, for example, it can be common for surface waters to
                be buried underground through an artificial tunnel system to facilitate
                urban development. See, e.g., Connectivity Report at 3-3. Examples
                include Jones Falls, which flows under Baltimore, Maryland, and
                daylights into the Baltimore's Inner Harbor; Park River which flows
                under Hartford, Connecticut, and daylights into the Connecticut River;
                and Mill Creek, a tributary of Lake Erie, which is diverted underground
                beneath downtown Erie, Pennsylvania, and daylights into Presque Isle
                Bay. These underground tunnels and similar channelized subsurface
                features do not become groundwater, even though they flow under the
                surface of the ground for a period of time. These features do not break
                the jurisdictional status of upstream tributaries subject to the
                conditions of paragraph (c)(12). In some cases where such channels
                never return to the surface or otherwise do not contribute surface
                water flow to a paragraph (a)(1) water in a typical year, the upstream
                surface water features may not be jurisdictional under the final rule.
                In all cases, the underground or buried portion of a channel network is
                not jurisdictional under the final rule. By comparison, tributaries
                that are relocated through a ditch or similar artificial surface
                channel are jurisdictional under the final rule so long as they
                continue to meet the flow conditions of paragraph (c)(12), including
                through the relocated portion.
                 In very limited circumstances, a tributary can naturally,
                temporarily flow underground as a channelized river or stream,
                maintaining the same or very nearly the same flow volume underground
                and at the downstream point where it returns to the surface. These
                natural systems are commonly referred to as subterranean rivers or
                streams and can occur as a result of unique geologic formations, such
                as sink holes and lava tubes. Examples include the Popo Agie River in
                Wyoming, which becomes subterranean and daylights about a quarter of a
                mile downstream; the Lost River in Indiana, which flows underground for
                eight miles from where it disappears, to where it rises at two places
                to flow aboveground again; and formations like the St. Marks and Santa
                Fe Rivers in Florida, which flow into large sinkholes and reappear a
                little over one-half mile and three miles downstream, respectively. The
                agencies do not consider subterranean rivers to be groundwater, even
                though they flow under the surface of the ground for what is generally
                a short period of time through subterranean natural channels. Although
                it has never been promulgated in regulatory text, the agencies have
                historically treated these subterranean flowing connections as not
                severing jurisdiction over the upstream surface channel, and the Corps
                has developed expertise in performing field verifications for these
                unique waters. The final rule does not change this longstanding
                practice and for the first time provides certainty and transparency
                regarding the agencies' approach for making jurisdictional
                determinations. The agencies have added the phrase ``subterranean
                river'' to paragraph (c)(12) to clarify that subterranean rivers, as
                compared to groundwater and other subsurface waters, may not break
                jurisdiction of upstream tributaries, including any jurisdictional
                lakes, ponds, and impoundments of jurisdictional waters that contribute
                surface water flow through these tributaries, depending on the factual
                circumstances. These subterranean rivers are distinguished in this
                final rule from other surface waters that, for example, may disappear
                underground and never daylight or daylight as an aquifer-fed spring or
                headwater of another river.\37\ The final rule does not maintain
                jurisdiction upstream of these other surface waters that may disappear
                underground and become part of the aquifer because the aquifer holds
                groundwater. The agencies have concluded that groundwater connections
                are an insufficient basis to assert jurisdiction over otherwise
                disconnected waters. In all cases, the underground portions of all
                waters are not jurisdictional under the final rule.
                ---------------------------------------------------------------------------
                 \37\ See Connectivity Report at A-1, defining ``aquifer'' as
                ``[a] geologic formation (e.g., soil, rock, alluvium) with permeable
                materials partially or fully saturated with ground water that yields
                ground water to a well, spring, or stream.'' (emphasis added).
                ---------------------------------------------------------------------------
                 The final rule also establishes that waters that do not contribute
                surface water to a downstream territorial sea or traditional navigable
                water in a typical year are not jurisdictional. These waters include
                completely losing streams (e.g., streams that experience a complete
                loss of surface water to a groundwater system) that do not reach
                traditional navigable waters in a typical year and waters that connect
                downstream only as a result of precipitation events that generally do
                not occur in a typical year (e.g., 10-, 25-, 50-, 100- or 500-year
                storms or floods). These waters do not provide a regular surface water
                connection to jurisdictional waters. Given that the term ``navigable''
                must be given some effect, and that the Supreme Court has cautioned the
                agencies to avoid interpretations of the statute that raise significant
                constitutional questions, the agencies conclude that such waters are
                more properly regulated as land and water resources of the States and
                Tribes. See SWANCC, 531 U.S. at 173.
                 As described in detail in Section III.G, adjacent wetlands are
                subject to a different jurisdictional test than tributaries, lakes,
                ponds, and impoundments of jurisdictional waters. According to the
                Rapanos plurality, for example, to be ``waters of the United States,''
                a tributary, lake, pond, or impoundment must be ``a relatively
                permanent body of water connected to traditional interstate navigable
                waters,'' 547 U.S. at 742 (Scalia, J., plurality); to be ``waters of
                the United States,'' a wetland must have ``a continuous surface
                connection'' to such relatively permanent waters, ``making it difficult
                to determine where the `water' ends and the `wetland begins.'' Id. The
                final rule defines ``adjacent wetlands'' to include all wetlands that
                abut--meaning to touch at least one point or side of--a territorial
                sea, traditional navigable water, tributary, lake, pond, or impoundment
                of a jurisdictional water. The final rule also includes other wetlands
                that are inseparably bound up with jurisdictional waters and relies on
                certain regular hydrologic surface connections to establish
                jurisdiction. For instance, the ``adjacent wetlands'' definition
                includes wetlands physically separated only by artificial structures
                such as dikes, or barriers, or divided by roads and similar structures
                so long as the structure allows for a direct hydrologic surface
                connection in a typical year: For example, through a culvert, flood or
                tide gate, pump, or similar feature. Jurisdiction of the wetland is
                severed when, in a typical year, an artificial feature does not allow
                for a direct hydrologic surface connection between the wetland and the
                jurisdictional water, or the wetland is not inundated by flooding from
                a territorial sea, traditional navigable
                [[Page 22280]]
                water, tributary, lake, pond, or impoundment of a jurisdictional water.
                See 547 U.S. at 742 (Scalia, J., plurality) (such wetlands ``do not
                implicate the boundary-drawing problem of Riverside Bayview,'' and thus
                do not have the ``necessary connection'' to jurisdictional waters that
                triggers CWA jurisdiction); see also id. at 747 (the plurality found
                ``no support for the inclusion of physically unconnected wetlands as
                covered `waters' '').
                 Wetlands are jurisdictional if they are inundated by flooding from
                a territorial sea, traditional navigable water, tributary, lake, pond,
                or impoundment of a jurisdictional water in a typical year. The
                agencies conclude that these wetlands are inseparably bound up with
                their adjacent jurisdictional waters and are therefore jurisdictional.
                See Rapanos, 547 U.S. at 732 (Scalia, J., plurality) (quoting Webster's
                New International Dictionary 2882 (2d ed. 1954)) (recognizing floods as
                ``making up such streams or bodies'' of water); id. at 740 (recognizing
                the principle that wetlands that adjoin other jurisdictional waters are
                part of those waters for purposes of CWA jurisdiction). The final rule
                likewise asserts jurisdiction over lakes, ponds, and impoundments of
                jurisdictional waters that are inundated in a typical year by flooding
                from a territorial sea, traditional navigable water, tributary, or
                another lake, pond, or impoundment of a jurisdictional water.
                 The final rule also provides that wetlands separated from
                jurisdictional waters only by a natural berm, bank, dune, or other
                similar natural feature are adjacent wetlands. These natural features
                are indicators of a sufficient hydrologic surface connection between
                the jurisdictional water and the wetland, and the agencies conclude
                that wetlands that are separated from jurisdictional waters only by
                such features are inseparably bound up with the adjacent jurisdictional
                waters and are therefore ``part of those waters.'' Id.
                 Physically remote isolated wetlands (i.e., wetlands that do not
                abut, are separated by more than a natural berm from, are not inundated
                by flooding in a typical year from, and do not have a direct hydrologic
                surface connection in a typical year to a jurisdictional non-wetland
                water) are not adjacent wetlands under the final rule. For example,
                impoundments that are formerly adjacent wetlands that are physically
                disconnected from other jurisdictional waters in a typical year are not
                jurisdictional under the final rule. Additionally, in keeping with the
                agencies' longstanding practice, the final rule maintains that wetlands
                can be jurisdictional only if they are adjacent to the territorial seas
                or a traditional navigable water, tributary, lake, pond or impoundment
                of a jurisdictional water. In 1986, the Corps defined ``waters of the
                United States'' as including ``wetlands adjacent to [other
                jurisdictional] waters (other than waters that are themselves
                adjacent),'' 51 FR 41250, meaning that wetlands obtain jurisdictional
                status under the CWA by virtue of their adjacency to traditional
                navigable waters, tributaries, and other actual waters, not by
                adjacency to other wetlands.\38\ In 2019, the agencies recodified this
                definition of ``waters of the United States.'' 84 FR 56626. Under this
                final rule, wetlands cannot be adjacent to other wetlands; they can
                only be adjacent to the territorial seas, a traditional navigable
                water, a tributary, or a lake, pond, or impoundment of a jurisdictional
                water. This holds true regardless of any hydrologic connection between
                a distinct wetland (i.e., a wetland delineated with boundaries distinct
                from those of an adjacent wetland) and an adjacent wetland when the
                distinct wetland is physically separated from the adjacent wetland by
                upland or other artificial or natural features. Because the agencies
                believe that the final rule's definition of ``adjacent wetlands'' is
                clear on the jurisdictional linchpin for adjacency (by tethering
                jurisdiction to paragraph (a)(1) through (3) waters), the agencies are
                not including the ``other than waters that are themselves adjacent''
                provision from the 2019 Rule (and earlier versions) in this final rule.
                ---------------------------------------------------------------------------
                 \38\ The agencies note that at oral argument in Rapanos, Chief
                Justice Roberts recognized this principle, stating that the 1986
                definition ``covers wetlands adjacent to waters other than waters
                that are themselves wetlands,'' and ``the Corps says we're not going
                to reach the wetland that is adjacent to another wetland.''
                Transcript of Oral Argument at 45, 47, Rapanos v. United States and
                Carabell v. United States, 547 U.S. 715 (2006) (Nos. 04-1034, 04-
                1384). The Chief Justice added that this ``suggests that even the
                Corps recognized that at some point you've got to say stop because
                logically any drop of water anywhere is going to have some sort of
                connection through drainage. And they're stopping there, and I
                wonder if we ought to take that same instinct that you see in [the
                wetlands definition] and apply it to your definition of tributary
                and say, at some point, the definition of tributary has to have an
                end. Otherwise, you're going to go and reach too far, beyond what
                Congress reasonably intended.'' Id. at 46.
                ---------------------------------------------------------------------------
                B. Territorial Seas and Traditional Navigable Waters
                1. What are the agencies finalizing?
                 The agencies are making no substantive textual changes to the
                longstanding inclusion of traditional navigable waters and the
                territorial seas in the definition of ``waters of the United States.''
                The agencies are finalizing this portion of the rule as proposed, with
                slight modifications discussed below. The final rule maintains these
                categories of ``waters of the United States'' but consolidates them
                into a single paragraph in the regulatory text.
                 Many commenters supported the retention of the agencies'
                longstanding foundational category of CWA jurisdiction, unchanged from
                previous regulatory text. They stated that the category was well
                understood, and its application guided by a developed body of case law.
                Most commenters supported integrating territorial seas into a single
                category with traditional navigable waters, agreeing with the agencies
                that it helped streamline the regulatory text, but some requested
                clarifications to maintain the distinction between the two types of
                waters. Some commenters requested that the agencies modify the test for
                traditional navigable waters by clarifying that such waters must be
                used to ``transport commerce'' rather than simply being ``used'' for or
                susceptible to ``use'' in interstate or foreign commerce, reflecting
                the terminology used by Congress in section 404(g) of the CWA.
                Responding to the agencies' request for comment on Appendix D, several
                commenters requested that the agencies eliminate or modify Appendix D
                to the U.S. Army Corps of Engineers Jurisdictional Determination Form
                Instructional Guidebook (hereinafter, ``Appendix D''),\39\ stating that
                Appendix D is confusing, overstates the agencies' authority under
                existing case law, and allows the agencies to regulate virtually any
                isolated water by misapplying the established judicial tests for
                navigability under the CWA. Other commenters suggested the agencies
                retain Appendix D as useful field guidance and to avoid
                [[Page 22281]]
                confusion associated with any changes in the agencies' approach to
                traditional navigable water determinations.
                ---------------------------------------------------------------------------
                 \39\ U.S. Army Corps of Engineers Jurisdictional Determination
                Form Instructional Guidebook, available at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2316. The agencies note that Appendix D is sometimes referred to as
                ``Appendix D to the Rapanos Guidance'' and was inadvertently
                referred to as such in the preamble to the proposed rule. The
                appendix actually resides as an attachment to the Jurisdictional
                Determination Form Instructional Guidebook that was published in
                2007 concurrently with the 2007 Rapanos Guidance. The Rapanos
                Guidance was later undated in 2008, but Appendix D has remained
                unchanged since 2007. Appendix D notes (at page 1) that ``EPA and
                the Corps are providing this guidance on determining whether a water
                is a `traditional navigable water' for purposes of the Rapanos
                Guidance, the Clean Water Act (CWA), and the agencies' CWA
                implementing regulations.'' This sentence is what is often used to
                link the Rapanos Guidance to Appendix D, as the two were intended to
                operate in tandem, with other agency resources, to assist in guiding
                field implementation of CWA jurisdictional determinations.
                ---------------------------------------------------------------------------
                 The agencies have considered all of the public comments received
                addressing these topics and are finalizing paragraph (a)(1) as
                proposed, with slight modifications to address questions regarding the
                inclusion of the territorial seas within a single category with
                traditional navigable waters. The agencies are not modifying the
                definition of ``traditional navigable waters'' as it has existed in
                regulatory text for decades. As discussed in Section II.G, when this
                final rule becomes effective, certain agency guidance documents,
                memoranda, and materials (e.g., the 2003 SWANCC Guidance and 2008
                Rapanos Guidance) will be rendered inoperative because they will no
                longer be necessary or material, and they may in fact create confusion
                as the agencies implement this final rule. However, because the
                agencies have not modified the definition of ``traditional navigable
                waters,'' the agencies are retaining Appendix D to help inform
                implementation of that provision of this final rule, as discussed
                further in Section III.B.2.
                2. Summary of Final Rule Rationale and Public Comment
                 The final rule defines ``waters of the United States'' to encompass
                traditional navigable waters and the territorial seas. The agencies'
                existing definition of ``waters of the United States'' includes all
                waters that are currently used, or were used in the past, or may be
                susceptible to use in interstate or foreign commerce, including all
                waters which are subject to the ebb and flow of the tide. See, e.g., 33
                CFR 328.3(a)(1). This paragraph of the 2019 Rule (and previous
                regulations) encompasses waters that are often referred to as waters
                more traditionally understood as navigable or ``traditional navigable
                waters.'' A separate paragraph of the 2019 Rule (and previous
                regulations) lists the territorial seas as jurisdictional. See 33 CFR
                328.3(a)(6). To streamline and simplify the definition of ``waters of
                the United States,'' the agencies are finalizing the rule as proposed
                to include both traditional navigable waters and the territorial seas
                into a single paragraph of jurisdictional waters. The final rule makes
                no other substantive changes to these historically regulated categories
                of waters.
                 The agencies note that the term ``territorial seas'' is defined in
                CWA section 502(8), 33 U.S.C. 1362(8), as ``the belt of the seas
                measured from the line of ordinary low water along that portion of the
                coast which is in direct contact with the open sea and the line marking
                the seaward limit of inland waters, and extending seaward a distance of
                three miles.'' The territorial seas establish the seaward limit of
                ``waters of the United States.'' The agencies did not propose including
                this definition in the rule because it is already defined by statute
                and are not including the definition or any further interpretation in
                the final rule.
                 In this final rule, the agencies are streamlining the regulation so
                that the first category of jurisdictional waters includes both
                traditional navigable waters and the territorial seas. Most commenters
                on this topic agreed with the proposal to combine the territorial seas
                and traditional navigable waters into one paragraph of the regulation,
                stating that it would streamline and simplify the definition of
                ``waters of the United States,'' and makes practical sense since the
                jurisdictional status of other categories of waters relies on their
                surface water connection to either a traditional navigable water or the
                territorial seas.
                 In the proposed rule, the agencies included the territorial seas as
                a type of traditional navigable water because the agencies had not
                identified an instance in which a territorial sea would not also be
                considered traditionally navigable and thus proposed that the broader
                term should suffice. A few commenters expressed concern that the
                proposed rule implied that the definition of ``waters of the United
                States'' included only the portions of the territorial seas that are
                navigable and capable of use in interstate or foreign commerce. The
                agencies did not intend to exclude any portion of the territorial seas
                as the term is defined in CWA section 502(8), 33 U.S.C. 1362(8). To
                avoid any confusion, the agencies have made minor modifications to the
                proposed rule text to further clarify that this category of
                foundational waters includes both traditional navigable waters and the
                territorial seas. The final rule states that the category of ``waters
                of the United States'' defined in paragraph (a)(1) includes ``the
                territorial seas, and water which are currently used, or were used in
                the past, or may be susceptible to use in interstate or foreign
                commerce, including waters which are subject to the ebb and flow of the
                tide.''
                 The agencies have not changed their interpretation of traditional
                navigable waters in this final rule, and the agencies are retaining
                Appendix D to help inform implementation of this provision with
                additional clarification in this notice in response to comments. As
                discussed in Section II.E, the definition of navigable-in-fact waters
                originates with the Supreme Court's decision in The Daniel Ball, 77
                U.S. (10 Wall.) 557 (1870). In that case, the Supreme Court stated:
                 Those rivers must be regarded as public navigable rivers in law
                which are navigable in fact. And they are navigable in fact when
                they are used, or are susceptible of being used, in their ordinary
                condition, as highways for commerce, over which trade and travel are
                or may be conducted in the customary modes of trade and travel on
                water.
                 Id. at 563. As explained by the Supreme Court in 2012, ``[t]he
                Daniel Ball formulation has been invoked in considering the
                navigability of waters for purposes of assessing federal regulatory
                authority under the Constitution, and the application of specific
                federal statutes, as to the waters and their beds.'' PPL Montana, LLC
                v. Montana, 565 U.S. 576, 592 (2012). ``With respect to the federal
                commerce power, the inquiry regarding navigation historically focused
                on interstate commerce.'' Id. at 593. The Supreme Court further
                explained that, ``of course, the commerce power extends beyond
                navigation'' and cautioned ``that the test for navigability is not
                applied the same way'' in all cases. Id. at 592-93; see also Kaiser
                Aetna v. United States, 444 U.S. 164, 171 (1979) (``[A]ny reliance upon
                judicial precedent [in this area] must be predicated upon careful
                appraisal of the purpose for which the concept of navigability was
                invoked in a particular case.'' (internal quotation marks, citation
                omitted, and emphasis in original)). But generally, navigability for
                purposes of federal regulatory authority under the federal commerce
                power encompasses waters that were ``once navigable but are no
                longer,'' PPL Montana, 565 U.S.at 592 (citing Economy Light & Power Co.
                v. United States, 256 U.S. 113, 123-24 (1921)), ``waters that only
                recently have become navigable,'' id. (citing Philadelphia Co. v.
                Stimson, 223 U.S. 605, 634-35 (1912)), and waters that ``are not
                navigable and never have been but may become so by reasonable
                improvements,'' id. at 592-93 (citing United States v. Appalachian
                Elec. Power Co., 311 U.S. 377, 407-08 (1940)). The agencies note that
                this summary articulated by the Supreme Court in 2012 generally
                reflects the basic structure of the longstanding jurisdictional test
                for ``traditional navigable waters'' retained in paragraph (a)(1) of
                the final rule.
                 Many commenters expressed support for the agencies' decision to
                retain the existing regulatory text describing traditional navigable
                waters. These
                [[Page 22282]]
                commenters stated that the existing text is clear, concise,
                predictable, and well understood by the public. Other commenters
                expressed concern about implementation of the regulation and guidance
                and suggested modifications to the regulation. Some commenters
                suggested clarifying that traditional navigable waters must be used to
                ``transport commerce,'' as that is the phrase Congress used to describe
                the waters over which the Corps retains permitting authority when
                States and Tribes assume CWA section 404 permitting. See 33 U.S.C.
                1344(g). As discussed in Section II.E, and consistent with a technical
                advisory committee report submitted to EPA as part of an effort to
                modernize the section 404(g) assumption process (see n.28), section
                404(g) refers to RHA section 10 waters. Some commenters recommended
                that the agencies adopt the RHA section 10 definition and the two-part
                legal test established by The Daniel Ball for ``navigable waters of the
                United States'' as the test for ``traditional navigable waters'' for
                purposes of implementing the term ``waters of the United States'' under
                the CWA. That test requires first that a water be navigable-in-fact,
                and second that commerce be transported across State or foreign lines
                on those waters. The Daniel Ball, 77 U.S. (10 Wall.) at 563.
                 The Supreme Court has not spoken directly to the precise meaning of
                the phrase ``traditional navigable waters'' as that term applies in the
                CWA context, but it has stated that the statutory ``term `navigable'
                has at least the import of showing us what Congress had in mind as its
                authority for enacting the CWA: Its traditional jurisdiction over
                waters that were or had been navigable in fact or which could
                reasonably be so made.'' SWANCC, 531 U.S. at 172. In the agencies'
                view, the Supreme Court has therefore signaled an acceptance of the
                first prong of The Daniel Ball test. Whether the second prong applies
                in full to the administrative definition of ``traditional navigable
                waters'' is less clear, but the legislative history suggests that
                Congress had in mind a more expanded notion of interstate commerce when
                enacting the CWA, including overland links to commercial navigation on
                navigable-in-fact waters.\40\ As described in Section II.E, the Supreme
                Court has stated that nothing in the legislative history of the Act
                suggests ``that Congress intended to exert anything more than its
                commerce power over navigation.'' SWANCC, 531 U.S. at 168 & n.3. The
                agencies therefore are not modifying the longstanding regulatory text
                for traditional navigable waters to specifically align it with the RHA
                test for jurisdiction, as some commenters suggested.
                ---------------------------------------------------------------------------
                 \40\ See Section II.E for additional discussion of the complex
                legislative history on this topic, as well as the detailed
                discussion of the same in the Albrecht & Nickelsburg article cited
                in note 25.
                ---------------------------------------------------------------------------
                 The agencies acknowledge that some commenters suggested that
                Appendix D as-applied in certain circumstances has led to confusion.
                For example, some commenters expressed concern that Appendix D could be
                read to support a conclusion that any water that can float a boat, even
                very shallow draft vessels like canoes and kayaks, is by definition
                ``susceptible'' to use in interstate commerce and therefore may be
                deemed a traditional navigable water. The agencies believe that this
                interpretation is inconsistent with the cases summarized in Appendix D
                and sweeps too broadly. For example, whether a water is susceptible to
                use in interstate commerce requires more than simply being able to
                float a boat to establish jurisdiction over navigable-in-fact waters
                under paragraph (a)(1); it requires evidence of physical capacity for
                commercial navigation and that it was, is, or actually could be used
                for that purpose. See, e.g., Appendix D (citing The Montello, 87 U.S.
                430, 441-42 (1874); United States v. Holt State Bank, 270 U.S. 49, 56
                (1926); United States v. Utah, 283 U.S. 64 (1931); United States v.
                Appalachian Elec. Power Co., 311 U.S. 377, 416 (1940)).
                 Other commenters provided examples of traditional navigable water
                determinations about which the commenters asserted that the capacity to
                float a boat in a water that is near an interstate highway was deemed
                sufficient to make a traditional navigable water determination under
                the paragraph (a)(1) standard. This interpretation is inconsistent with
                the applicable case law, including the cases discussed in Appendix D.
                Simply driving across a State line and using a waterbody, or having the
                potential to use a waterbody, is similar to the theory of jurisdiction
                that the Supreme Court specifically rejected in SWANCC. One of the
                arguments raised in support of the ``Migratory Bird Rule'' for CWA
                jurisdiction was that individuals cross State lines and engage in
                commercial activity to hunt or observe migratory birds that use
                isolated waters as habitat. See SWANCC, 531 U.S. at 166; id. at 195 &
                n.17 (Stevens, J., dissenting). The SWANCC Court rejected this
                interpretation of CWA jurisdiction because it raised ``significant
                constitutional questions'' that would require the agencies to
                ``evaluate the precise object or activity that, in the aggregate,
                substantially affects interstate commerce.'' Id. at 173-74. The
                ``substantial effects'' test is the most expansive of the three primary
                bases for exercising congressional authority under the Commerce Clause
                articulated by the Supreme Court in United States v. Lopez, 514 U.S.
                549, 558-59 (1995). This application of the ``substantial effects''
                test to assert CWA jurisdiction over waters beyond those more
                traditionally understood as navigable was not intended by Appendix D
                and has been rejected by the SWANCC Court because it was inconsistent
                with Congress' intent to exercise its more traditional ``commerce power
                over navigation.'' SWANCC, 531 U.S. at 173 & n.8. Thus, the legal
                principles summarized in Appendix D were not intended to endorse, and
                should not be interpreted as endorsing, the application of the
                ``substantial effects'' test to CWA jurisdiction, or otherwise
                suggesting that the mere capacity to float a boat makes a waterbody
                susceptible to commercial navigation.
                 The agencies intend to update their guidance materials, if and as
                necessary, as the agencies begin to implement the revised tests for
                jurisdiction established by the final rule, both initially and as the
                agencies gain field experience to address implementation questions that
                may arise. As part of that process, the agencies will continue to
                evaluate prior guidance on how to apply established case law principles
                to traditional navigable water determinations. The agencies will also
                implement field elevation procedures should difficult legal questions
                arise, including requiring such interpretations to be reviewed by
                senior legal staff at each of the agencies' respective headquarters.
                Implementation of this section of the traditional navigable waters
                provision of paragraph (a)(1) in the final rule will be case-specific,
                as it has always been. This case-specific analysis will include
                relevant portions of EPA and Corps regulations, prior determinations by
                the Corps and by the federal courts, and case law. Should the agencies
                determine that additional, more formal guidance on traditional
                navigable waters is warranted, the agencies will develop any such
                guidance in compliance with Executive Order 13891, and with any
                applicable public participation requirements.
                C. Interstate Waters
                1. What are the agencies finalizing?
                 Consistent with the proposal, this final rule removes interstate
                waters, including interstate wetlands, as a separate category of
                ``waters of the
                [[Page 22283]]
                United States.'' The agencies are finalizing this aspect of the
                proposal to more closely align the regulatory definition with the
                constitutional and statutory authorities reflected in the CWA and
                judicial interpretations of the term ``navigable waters,'' while
                balancing the statute's objective to restore and maintain the integrity
                of the nation's waters and its policy directives to preserve and
                protect the rights and responsibilities of the States.
                 Many commenters supported the removal of interstate waters and
                wetlands as an independent category of ``waters of the United States.''
                Those commenters stated that such a category was not authorized by the
                CWA and that, as proposed by the agencies, waters must be connected to
                traditional navigable waters to be jurisdictional under the CWA.
                Commenters also stated that interstate waters and wetlands that
                actually fall within the scope of CWA jurisdiction would be covered by
                the other categories of waters as proposed. Other commenters opposed
                removing interstate waters as an independent jurisdictional category.
                Those commenters stated that any water that crosses a State line is by
                definition a ``water of the United States.'' The same is true, some
                commenters added, for waters that cross tribal boundaries. Additional
                commenters added that the proposed rule would arbitrarily narrow the
                scope of CWA jurisdiction over ecologically important waters and
                recommended that the agencies continue to regulate interstate waters.
                Other commenters suggested that the exclusion for ephemeral features,
                if finalized, would help balance the inclusion of interstate waters as
                a category.
                 The agencies have considered this diverse range of opinions, and
                for the reasons discussed below, have concluded that the best
                interpretation of the CWA and its legislative history is to finalize
                the regulatory text as proposed, without a separate interstate waters
                category. Interstate waters and interstate wetlands remain subject to
                CWA jurisdiction under the final rule if they are waters identified in
                paragraph (a)(1), (2), (3), or (4) (generally referred to as
                ``paragraph (a)(1) through (4) waters'' or ``a paragraph (a)(1) through
                (4) water'' in this notice).
                2. Summary of Final Rule Rationale and Public Comment
                 The agencies have evaluated their earlier legal and policy
                rationales supporting the inclusion of interstate waters as a separate
                category of ``waters of the United States'' and comments on the
                proposed rule and are not including this category in the final rule.
                The agencies have concluded that the regulation of interstate waters as
                a standalone category is based on an overly broad reading of the
                original Water Pollution Control Act (WPCA) of 1948 and lacks
                foundation in statutory text of the 1972 CWA amendments. The WPCA
                stated that the ``pollution of interstate waters in or adjacent to any
                State or States (whether the matter causing or contributing to such
                pollution is discharged directly into such waters or reaches such
                waters after discharge into a tributary of such waters), which
                endangers the health or welfare of persons in a State other than that
                in which the discharge originates, is hereby declared to be a public
                nuisance and subject to abatement as herein provided.'' WPCA of 1948,
                2(d)(1), (4), 62 Stat. 1155, 1156-57. The statute defined ``interstate
                waters'' as ``all rivers, lakes, and other waters that flow across, or
                form a part of, State boundaries.'' Id. at 10(e), 62 Stat. 1161.
                 In 1961, Congress amended the statute to substitute the term
                ``interstate or navigable waters'' for ``interstate waters'' in the
                statute's enforcement provision while making minor changes to the
                definition of ``interstate waters.'' See Public Law 87-88, 75 Stat. 208
                (1961). In 1965, Congress again amended the statute to require states
                to develop water quality standards for all ``interstate waters'' within
                their borders. See Public Law 89-234, 79 Stat. 908 (1965). In 1972,
                Congress amended the statute again and selected the term ``navigable
                waters'' as the operative term for the major regulatory programs
                established by the 1972 amendments, dropping the definition of
                ``interstate waters'' from the statute. See, e.g., 33 U.S.C. 1362(7)
                (defining ``navigable waters'' as ``waters of the United States''). In
                doing so, however, Congress allowed States to retain existing water
                quality standards for interstate waters developed under the pre-1972
                statutory program. See 33 U.S.C. 1313(a).
                 The EPA promulgated its first regulatory definition for the term
                ``waters of the United States'' in 1973. 38 FR 13528 (May 22, 1973). In
                that regulation, the EPA administratively determined that ``interstate
                waters'' should be a separate category of ``waters of the United
                States,'' distinct from the traditional navigable waters category, and
                until this final rule the agencies had retained it as a separate
                category.
                 The agencies previously viewed navigable and interstate waters as
                having distinct and separate meanings because Congress in 1961 used
                both terms in the statute. The agencies explained their prior
                interpretation in part through the doctrine of congressional
                acquiescence, in that Congress was aware of the EPA's retention of
                ``interstate waters'' as a separate category when amending the CWA in
                1977 (making no amendments to remove the agencies' regulatory inclusion
                of interstate waters), and therefore acquiesced to its inclusion as a
                separate category. The agencies have also historically relied on two
                Supreme Court cases--Illinois v. City of Milwaukee, 406 U.S. 91 (1972)
                and City of Milwaukee v. Illinois, 451 U.S. 304 (1981)--addressing
                interstate water pollution to further support their prior
                interpretation. In the 1972 case, which was decided prior to the date
                of the 1972 CWA amendments, the Supreme Court referred to the two
                categories in the disjunctive, implying that the Court viewed the pre-
                1972 statutory program as encompassing two separate categories. See
                Illinois, 406 U.S. at 102 (``it is federal, not state, law that in the
                end controls pollution of interstate or navigable waters'') (emphasis
                added). The 1981 case is described further below. The agencies also
                have referred to section 303(a) of the CWA as further evidence that
                Congress intended ``interstate waters'' to be retained as an
                independent category of jurisdictional waters because that provision
                authorized water quality standards for ``interstate waters'' developed
                following the 1965 amendments to remain in effect, subject to revision
                under the new statutory program. A more complete summary of the
                agencies' prior legal position with respect to interstate waters was
                included in a Technical Support Document prepared in support of the
                2015 Rule (``2015 Rule TSD'').\41\ The agencies now conclude that their
                prior interpretation is inconsistent with the text and structure of the
                CWA.
                ---------------------------------------------------------------------------
                 \41\ U.S. EPA and U.S. Department of the Army. Technical Support
                Document for the Clean Water Rule: Definition of Waters of the
                United States (May 2015) (Docket ID: EPA-HQ-OW-2011-0880-20869),
                available at https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-20869.
                ---------------------------------------------------------------------------
                 When Congress enacted the 1972 CWA amendments, it selected the term
                ``navigable waters'' to frame the scope of federal regulatory
                jurisdiction under the Act. Rather than interpreting those amendments
                as retaining ``interstate waters'' as a separate and distinct category
                of ``waters of the United States,'' the agencies now conclude that a
                more natural interpretation of the 1972 amendments is an express
                rejection of that independent category, as Congress had before it both
                options within the scope of the statute it was modifying. Congress
                specifically did not carry that term forward as the operative phrase
                for
                [[Page 22284]]
                federal jurisdiction. Under basic canons of statutory construction, the
                agencies begin with the presumption that Congress did so intentionally.
                See, e.g., Stone v. INS, 514 U.S. 386, 397 (1995) (``When Congress acts
                to amend a statute, we presume it intends its amendment to have real
                and substantial effect.'').
                 Congressional acquiescence is a doctrine of limited application and
                was specifically rejected as a basis for expansive federal jurisdiction
                in SWANCC in the context of analyzing the Corps' 1977 regulations.
                SWANCC, 531 U.S. at 170-71 (``Although we have recognized congressional
                acquiescence to administrative interpretations of a statute in some
                situations, we have done so with extreme care.''). The plurality
                opinion in Rapanos further elaborated, when also rejecting the notion
                that Congress acquiesced to the Corps' 1977 regulations, that
                ``Congress takes no governmental action except by legislation. What the
                dissent refers to as `Congress' deliberate acquiescence' should more
                appropriately be called Congress's failure to express any opinion.''
                Rapanos, 547 U.S. at 750 (Scalia, J., plurality). The plurality
                explained that we cannot know whether Congress' inaction resulted from
                their belief that the Corps' regulations were correct, or from other
                reasons, such as confidence that courts would correct excesses or
                political considerations. See SWANCC, 531 U.S. at 169-70, 178 n.5
                (``Absent such overwhelming evidence of acquiescence, we are loath to
                replace the plain text and original understanding of a statute with an
                amended agency interpretation.''). The agencies now conclude,
                consistent with the admonitions of SWANCC and the Rapanos plurality,
                that the doctrine of congressional acquiescence is not a sound basis to
                guide the agencies' decision regarding the scope of federal
                jurisdiction over certain waters in this final rule, particularly as it
                applies to interstate waters divorced from any notion of commercial
                navigability.
                 The legislative history of the 1972 amendments, in fact, supports
                the agencies' conclusion that Congress did not consider interstate
                waters and navigable waters to be two separate and distinct categories,
                and instead referred to terms in the pre-1972 statutory regime
                conjunctively as ``interstate navigable waters.'' S. Rep. No. 92-414,
                at 2 (1971) (``Each State was required by the 1965 Act to develop
                standards for water quality within its boundaries. These standards were
                to be applied to all interstate navigable waters flowing through the
                State; intrastate waters were not included.'') (emphasis added); id. at
                4 (``The setting of water quality standards for interstate navigable
                waters . . . is the keystone of the present program for control of
                water pollution.'') (emphasis added); id. (``The States have first
                responsibility for enforcement of their standards. When approved by the
                [EPA], however, the standards for interstate navigable waters become
                Federal-State standards.'') (emphasis added). In fact, the legislative
                history suggests that Congress modified the text of the statute in 1972
                in part because the States had narrowly interpreted the phrase
                ``interstate'' to apply only to interstate navigable waters and had
                failed to establish water quality standards for the intrastate
                tributaries to such waters. See, e.g., id. at 77 (``The control
                strategy of the Act extends to navigable waters . . . . Through a
                narrow interpretation of the definition of interstate waters the
                implementation [of the] 1965 Act was severely limited.''); 118 Cong.
                Rec. 10240 (1972) (the amendment ``expands the coverage of the law to
                intrastate, as well as interstate navigable waterways'') (emphasis
                added). In 1976, the Supreme Court shared the same view of the pre-1972
                statutory scheme: ``Before it was amended in 1972, the Federal Water
                Pollution Control Act employed ambient water quality standards
                specifying the acceptable levels of pollution in a State's interstate
                navigable waters as the primary mechanism in its program for the
                control of water pollution.'' EPA v. California, 426 U.S. 200, 202
                (1976) (emphasis added) (footnote omitted). This history suggests that
                the section 303(a) provision relating to existing water quality
                standards for ``interstate waters'' was referring to ``interstate
                navigable waters,'' not interstate waters more broadly.
                 Neither Supreme Court case previously relied on by the agencies and
                discussed in the 2015 Rule TSD addressed the specific question whether
                ``interstate waters'' and ``navigable waters'' are separate and
                distinct categories of jurisdictional waters under the CWA. They
                instead addressed interstate water pollution generally, and the water
                at issue in those cases was Lake Michigan, an interstate navigable-in-
                fact water. The 1981 decision, however, did recognize that the 1972
                amendments ``were viewed by Congress as a `total restructuring' and
                `complete rewriting' of the existing water pollution legislation
                considered in that case.'' Milwaukee, 451 U.S. at 317 (citing
                legislative history of the 1972 CWA amendments). This supports the
                agencies' conclusion that prior iterations of the statute, referring to
                both interstate waters and navigable waters, were replaced with a
                completely new program in 1972, not that certain aspects of that
                program continued through congressional acquiescence in a later
                regulatory determination. The final rule therefore eliminates
                ``interstate waters'' as a separate category of ``waters of the United
                States.''
                 By eliminating a separate category for interstate waters, the final
                rule adheres to the legal principles discussed in Section II.E by
                including within the definition of ``waters of the United States''
                traditional navigable waters, the territorial seas, and waters subject
                to the ebb and flow of the tide; tributaries to such waters; certain
                lakes, ponds, and impoundments of otherwise jurisdictional waters; and
                wetlands adjacent to jurisdictional waters. Because the agencies'
                authority flows from Congress' use of the term ``navigable waters'' in
                the CWA, the agencies lack authority to regulate waters untethered from
                that term. Nothing in the legislative history of the 1972 CWA
                amendments ``signifies that Congress intended to exert anything more
                than its commerce power over navigation.'' SWANCC, 531 U.S. at 168 n.3.
                 Therefore, those interstate waters that would satisfy the
                definitions in this final rule are jurisdictional; interstate waters
                without any surface water connection to traditional navigable waters or
                the territorial seas are not within the agencies' authority under the
                CWA and are more appropriately regulated by the States and Tribes under
                their sovereign authorities.
                 The agencies' rationale is supported by the U.S. District Court for
                the Southern District of Georgia's remand order. Georgia v. Wheeler,
                No. 2:15-cv-00079, 2019 WL 3949922 (S.D. Ga. Aug. 21, 2019). There, the
                court directly addressed the 2015 Rule's assertion of authority over
                all interstate waters, including nonnavigable interstate waters. Id. at
                *10-13. The court found that ``the inclusion of all interstate waters
                in the definition of `waters of the United States,' regardless of
                navigability, extends the Agencies' jurisdiction beyond the scope of
                the CWA because it reads the term navigability out of the CWA.'' Id. at
                *12. The court also found that, because the 2015 Rule would assert
                jurisdiction over tributaries, adjacent waters, and case-by-case waters
                based on their relationship to non-navigable isolated interstate
                waters, it would result in federal jurisdiction over even the most
                remote and isolated waters that the Supreme Court held in SWANCC are
                beyond the
                [[Page 22285]]
                reach of the CWA. Id. at *13. The agencies agree with the court's
                analysis and conclusion.
                 This final rule marks a shift away from prior agency positions. The
                agencies received public comment that the proposal had failed to
                analyze potential impacts resulting from the removal of ``interstate
                waters'' as a separate category, but as noted in the preamble to the
                proposed rule, the agencies are not aware of any database that
                identifies the jurisdictional status of interstate waters based solely
                on the fact that they cross state lines, or any other resource that
                would identify these waters. The agencies therefore lack the ability to
                perform a comparative analysis with any precision. Some commenters
                provided examples of interstate waters that may lose jurisdictional
                status if the separate category is eliminated; however, the Corps' ORM2
                database does not contain any jurisdictional determinations based
                solely on a water's status as an interstate water. Since issuance of
                the Rapanos Guidance, the Corps has not tracked this category
                separately for approved jurisdictional determinations conducted under
                the Guidance in ORM2.
                 The agencies requested comment on the rationales in favor of and
                opposed to a separate jurisdictional category for ``interstate
                waters.'' Some commenters supported the proposal to remove ``interstate
                waters'' as a separate category, noting that there is no statutory or
                constitutional basis to regulate interstate waters that would not
                otherwise be jurisdictional and suggesting that the agencies lacked the
                authority to include a separate ``interstate'' category in earlier
                versions of the regulations. Other commenters opposed the proposal,
                asserting that the text and structure of the CWA, legislative history,
                and prior court cases, including Justice Scalia's discussion in
                Rapanos, demonstrate that the CWA applies to interstate waters
                regardless of navigability. The agencies considered these comments and,
                for the reasons explained above, conclude that the final rule most
                closely aligns with the agencies' constitutional and statutory
                authorities reflected in the CWA and relevant judicial interpretations
                of the term ``navigable waters'' and the legislative history of the
                CWA, while balancing the statute's objective to restore and maintain
                the integrity of the nation's waters and its policy directives to
                preserve and protect the rights and responsibilities of the States.
                 Some commenters stated that the agencies did not provide sufficient
                rationale for deviating from their prior analysis and interpretation,
                as provided in the 2015 Rule TSD. The agencies disagree, as the
                proposal clearly identified independent reasons questioning the
                validity of the agencies' prior interpretation. The agencies' 2015 Rule
                TSD, for example, included three primary arguments supporting the prior
                interpretation: First, the language, structure, and history of the CWA
                demonstrate that Congress intended to include interstate waters in
                addition to navigable waters; second, the Supreme Court decisions in
                Rapanos and SWANCC did not constrain CWA jurisdiction over isolated,
                nonnavigable, interstate waters; and third, Supreme Court precedent
                supports jurisdiction over interstate waters, regardless of
                navigability. These arguments are addressed in the proposal and in
                earlier sections of this notice, but the agencies provide additional
                detail to respond to comments received as follows.
                 The 2015 Rule TSD analyzed two Supreme Court decisions to support
                its conclusion that interstate waters should be a separate category of
                jurisdiction under the CWA. The first decision was issued in 1972, just
                prior to the 1972 CWA amendments, and concluded that federal common law
                was appropriate to resolve a cross-border water pollution dispute among
                states where existing statutes did not address the dispute. Illinois,
                406 U.S. 91. The Court found that where ``no fixed rules'' govern
                cross-boundary pollution disputes, ``these will be equity suits in
                which the informed judgment of the chancellor will largely govern.''
                Id. at 107-08.
                 The second decision was issued in 1981, and it analyzed the effect
                of the 1972 amendments on a federal common law claim concerning the
                same cross-border water pollution dispute that was presented the 1972
                case. City of Milwaukee, 451 U.S. 304. In that case, the Court
                acknowledged the 1972 amendments and noted that ``[t]he establishment
                of such a self-consciously comprehensive program by Congress, which
                certainly did not exist when Illinois v. Milwaukee was decided,
                strongly suggests that there is no room for courts to attempt to
                improve on that program with federal common law.'' Id. at 319 (emphasis
                added).
                 Contrary to the assertions in the 2015 Rule TSD, however, the Court
                did not conclude that the CWA occupies the field with regard to all
                interstate waters.\42\ Instead, the Court considered the facts of the
                case before it--whether NPDES permits issued by an authorized State in
                compliance with the CWA could be modified or augmented by federal
                common law claims brought by a downstream State. Focusing on
                respondents' claims that discharges from the facilities were causing a
                public nuisance, the Court observed that, ``the action of Congress in
                supplanting the federal common law is perhaps clearest when the
                question of effluent limitations for discharges from the two treatment
                plants is considered.'' City of Milwaukee, 451 U.S. at 319-20. The
                Court identified the numerous provisions of the permits that addressed
                discharges and overflows from the facilities, and the State-initiated
                enforcement action contemplated by the CWA, and concluded that
                ``[t]here is no `interstice' here to be filled by federal common law:
                Overflows are covered by the Act and have been addressed by the
                regulatory regime established by the Act. Although a Federal court may
                disagree with the regulatory approach taken by the agency . . . such
                disagreement alone is no basis for the creation of federal common
                law.'' Id. at 323.
                ---------------------------------------------------------------------------
                 \42\ See U.S. EPA and Department of the Army, Technical Support
                Document of the EPA-Army Clean Water Rule at 210 (May 20, 2015)
                (``2015 Rule TSD'') (Docket ID: EPA-HQ-OW-2011-0880-20869) available
                at https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-20869.
                (``In City of Milwaukee, the Court found that the CWA was the
                `comprehensive regulatory program' that `occupied the field' (451
                U.S. 317) with regard to interstate water pollution, eliminating the
                basis for an independent common law of nuisance to address
                interstate water pollution.''). The 2015 Rule TSD also asserts that
                the Court ``expressly overruled'' its decision in Illinois; however,
                a more precise statement would be that the Court found no federal
                common law remedy available ``at least so far as concerns the claims
                of respondents'' because Congress occupied the field with a federal
                regulatory program that establishes effluent limits and other
                specific requirements that supersede the ``often vague and
                indeterminate nuisance concepts and maxims of equity
                jurisprudence.'' City of Milwaukee, 451 U.S. at 317 (emphasis
                added).
                ---------------------------------------------------------------------------
                 The Court also noted that in its 1972 decision, the Court was
                concerned that the downstream State ``did not have any forum in which
                to protect its interests unless federal common law were created,'' City
                of Milwaukee, 541 U.S. at 325, but that the NPDES permitting provisions
                of the 1972 amendments ``provided ample opportunity for a State
                affected by decisions of a neighboring State's permit-granting agency
                to seek redress.'' Id. at 325-26 (identifying the CWA requirement to
                provide notice to affected States and opportunity to comment and
                request public hearings, the Wisconsin law that provides the same,
                affected States' opportunity under the CWA to petition the EPA to
                object to a NPDES permit, and noting that respondents did not take
                advantage of these provisions). The case therefore presented a dispute
                between States concerning NPDES permits lawfully issued for discharges
                into an otherwise
                [[Page 22286]]
                navigable water--Lake Michigan. The Supreme Court did not consider
                disputes outside of the NPDES permit program or those concerning non-
                navigable interstate waters, and the Court did not broadly conclude
                that the CWA occupies the field of all interstate water pollution.\43\
                All it had before it was the CWA, and as discussed in Section II,
                Congress chose not to exercise its full powers under the Commerce
                Clause when enacting the 1972 amendments. Congress specifically
                recognized that there are other land and water resources that are more
                appropriately regulated by the States and Tribes under their sovereign
                authorities. Field preemption cannot extend beyond the field. Hines v.
                Davidowitz, 312 U.S. 52, 78-79 (1941) (``[e]very Act of Congress
                occupies some field, but we must know the boundaries of that field
                before we can say that it has precluded a state from the exercise of
                any power reserved to it by the Constitution''); see also Gonzales v.
                Oregon, 546 U.S. 243, 275 (2006); Medtronic, Inc. v. Lohr, 518 U.S.
                470, 475 (1996); Metropolitan Life Ins. Co. v. Massachusetts, 471 U.S.
                724, 756 (1985)).
                ---------------------------------------------------------------------------
                 \43\ In a footnote, the 2015 Rule TSD identifies two other
                Supreme Court decisions and concludes that ``[n]othing in either
                decision limits the applicability of the CWA to interstate water
                pollution disputes involving navigable interstate waters or
                interstate waters connected to navigable waters.'' 2015 Rule TSD at
                211 n.16 (referencing International Paper v. Ouellette, 479 U.S. 481
                (1987), and Arkansas v. Oklahoma, 503 U.S. 91 (1992)). Similar to
                the facts of City of Milwaukee, both of these cases addressed
                disputes that arose in the CWA's NPDES permitting context for waters
                that would otherwise be jurisdictional--Lake Champlain and the
                Illinois River. In neither case was the Court asked to consider
                whether or how the CWA may apply to non-navigable interstate waters,
                and these cases do not provide useful context or precedent on that
                issue. The 2015 Rule TSD similarly concluded that neither SWANCC nor
                Rapanos addressed or limited CWA jurisdiction over non-navigable
                interstate waters. See Section II.E of this notice for the agencies'
                detailed analysis of the SWANCC and Rapanos decisions.
                ---------------------------------------------------------------------------
                 The agencies also requested comment on an alternative approach that
                would retain ``interstate waters'' as a separate category, reflecting
                longstanding agency practice, and whether the term ``interstate''
                should be interpreted as crossing between States, between States and
                tribal lands, between States and/or tribal lands and foreign countries,
                or other formulations. Some commenters opposed this alternative
                approach, stating that the agencies lacked the authority to codify or
                implement it. Other commenters supported retaining ``interstate
                waters'' as a separate category and expressed concern that removing it
                would eliminate the EPA's role as a co-regulator in cross-boundary
                disputes over water quality.
                 The CWA provides two opportunities for the EPA to mediate disputes
                among States: The section 401(a)(2) neighboring jurisdiction
                notification provisions for federally permitted projects that may
                discharge to navigable waters and the section 319(g) provisions
                allowing the EPA to convene an interstate management conference to
                address cross-boundary nonpoint pollution in navigable waters. In the
                past, these provisions have been invoked infrequently by States, and
                the agencies do not expect a significant increase in cross-boundary
                disputes as a result of this rulemaking. In addition, the EPA can
                address concerns of States whose waters may be affected by the issuance
                of a permit in another State through the permit objection process
                pursuant to CWA sections 402(b)(5), 402(d)(d), and 40 CFR 123.44(c)(2).
                As demonstrated in City of Milwaukee, if a cross-boundary dispute is
                one that is contemplated and addressed by the CWA, such as the
                sufficiency of effluent limits in a NPDES permit, the statute has
                occupied the field and federal common law does not provide a remedy.
                451 U.S. at 317. However, if a State NPDES permit or a section 401
                certification is not required, the EPA does not have a role within the
                CWA permitting framework to address cross-boundary disputes; similarly,
                if a water is not a ``water of the United States,'' then the EPA's
                conference convening authorities under section 319(g) would not apply.
                In addition, and as described in the Section II.B of this notice, the
                CWA provides the EPA with numerous other authorities to provide
                technical assistance to States and Tribes to facilitate the management
                of non-jurisdictional waters.\44\
                ---------------------------------------------------------------------------
                 \44\ In addition, the notion that categorical federal regulation
                of interstate waters is necessary to end water pollution disputes
                between States would call into the question the need for CWA section
                103 (``Interstate Cooperation and Uniform Laws''), 33 U.S.C. 1253,
                which establishes a framework for the Administrator to encourage
                cooperation between States for the prevention and control of
                pollution.
                ---------------------------------------------------------------------------
                 Under the current framework, the remedies available for cross-
                boundary water pollution disputes over non-jurisdictional waters
                depends upon the parties and the issues in the case. As an initial
                matter, many State programs regulate more waters than are covered by
                the federal definition of ``waters of the United States'' and may have
                similar notification provisions in place for States affected by a
                State-issued NPDES permit. See e.g., Wis. Stat. 281.33 (authorizing
                Wisconsin to issue NPDES permits for all waters of the State); Wis.
                Admin. Code. 203.03 (providing notice during the NPDES process to other
                agencies, including other States potentially affected by the
                discharge). This important fact supports the agencies' conclusion that
                all States protect their water resources under State law and many have
                the ability and expertise to do so in the absence of federal
                regulation, as discussed in more detail in the Resource and
                Programmatic Assessment for the final rule. As they do today, remedies
                for pollution disputes among States that do not implicate CWA sections
                319(g), 401, or 402 would likely derive from federal common law under
                the Supreme Court's original jurisdiction. See, e.g., Illinois, 406
                U.S. at 98-99. Remedies for disputes between a State and a public or
                private party would likely derive from State or federal common law and
                be heard by State or Federal courts. See id. at 100, 107-08;
                International Paper, 479 U.S. at 497-500.
                D. Tributaries
                1. What are the agencies finalizing?
                 In this final rule, the agencies retain ``tributaries'' as a
                category of jurisdictional waters subject to CWA jurisdiction. The
                final rule defines ``tributary'' to mean a river, stream, or similar
                naturally occurring surface water channel that contributes surface
                water flow to the territorial seas or traditional navigable waters
                (paragraph (a)(1) waters) in a typical year either directly or through
                one or more tributaries (paragraph (a)(2) waters), lakes, ponds, and
                impoundments of jurisdictional waters (paragraph (a)(3) waters), or
                adjacent wetlands (paragraph (a)(4) waters). A tributary must be
                perennial or intermittent in a typical year. The alteration or
                relocation of a tributary does not modify its jurisdictional status as
                long as it continues to satisfy the flow conditions of this definition.
                A tributary does not lose its jurisdictional status if it contributes
                surface water flow to a downstream jurisdictional water in a typical
                year through a channelized non-jurisdictional surface water feature,
                through a subterranean river, through a culvert, dam, tunnel, or
                similar artificial feature, or through a debris pile, boulder field, or
                similar natural feature.
                 As discussed in greater detail in Section III.E, the term
                ``tributary'' includes a ditch that either relocates a tributary, is
                constructed in a tributary, or is constructed in an adjacent wetland as
                long as the ditch satisfies the flow conditions of the ``tributary''
                definition. A ditch can also be a traditional navigable water if it
                meets the
                [[Page 22287]]
                conditions of that category. The agencies are excluding all other
                ditches from the definition of ``waters of the United States,'' other
                than those identified in paragraph (a)(1) or (2) and ditches any
                portion of which are constructed in an adjacent wetland that lack
                perennial or intermittent flow (meaning they do not satisfy the
                ``tributary'' definition in paragraph (c)(12)) but that develop
                wetlands in all or portions of the ditch that satisfy the ``adjacent
                wetlands'' definition in paragraph (c)(1). Excluded ditches may be
                subject to regulation under State or tribal law and could potentially
                be conveyances of discharges of pollutants from ``point sources''
                subject to CWA permitting (see 33 U.S.C. 1362(14)) if they convey
                pollutants from a discharger to jurisdictional waters.
                 Regardless of the name they are given locally (e.g., creek, bayou,
                branch, brook, run), or their size (e.g., discharge volume, width,
                depth, stream order), waters that meet the definition of ``tributary''
                are jurisdictional under this final rule. Surface features that flow
                only in direct response to precipitation, such as ephemeral streams,
                swales, gullies and rills, are not tributaries. These features lack the
                required perennial or intermittent flow to satisfy the ``tributary''
                definition and therefore are not jurisdictional. However, such features
                may convey surface water flow from an upstream jurisdictional water to
                a downstream jurisdictional water without severing jurisdiction of the
                tributary.
                 The regulatory status of tributaries has evolved over the last
                several decades, resulting in confusion for the regulated community and
                regulators alike. Some commenters said that all channels on the
                landscape that convey water, regardless of flow regime, should be
                subject to CWA regulation, including both natural and artificial
                channels. Others asserted that Congress intended to regulate only
                traditional navigable waters, and navigable tributaries to those
                waters. Some would regulate all ditches, while others would exclude all
                ditches from CWA jurisdiction. Some stated that all ephemeral washes
                should be regulated, while others viewed ephemeral features as more
                like land that is wet after it rains. Some would extend jurisdiction to
                perennial rivers and streams and cut off jurisdiction for intermittent
                or seasonal waters. Others would regulate intermittent waters based on
                a minimum number of days of continuous flow, such as 30, 90, or 185.
                Even the Supreme Court has struggled with articulating clear principles
                governing which tributaries to traditional navigable waters should be
                subject to CWA jurisdiction, as evidenced by the fractured opinion in
                Rapanos. What is clear from that opinion, however, is that a majority
                of the Court believed the agencies' existing standard for tributaries
                at that time raised serious questions regarding the scope of the
                agencies' authority under the CWA. See Section II.E.2.
                 The agencies proposed a definition for ``tributary'' that they
                believed respected their statutory and constitutional authorities,
                consistent with principles established in Riverside Bayview, SWANCC,
                and Rapanos. Many commenters agreed with the proposal, indicating that
                it balanced federal authority over the core waters targeted by Congress
                under the CWA with waters that are more appropriately regulated solely
                by the States and Tribes. Others argued that the proposed ``tributary''
                definition regulated too broadly, preferring instead that the agencies
                restrict jurisdiction to perennial tributaries only. Others argued that
                the agencies failed to regulate ecologically important ephemeral
                reaches and cut off jurisdiction to headwater reaches that are
                important to the tributary network.
                 The agencies have considered all comments received and have crafted
                a final regulatory definition of ``tributary'' designed to adhere to
                the legal principles articulated in this notice and that provides a
                predictable, implementable regulatory framework. The agencies are
                finalizing their proposal to regulate perennial and intermittent
                tributaries to traditional navigable waters, while excluding ephemeral
                streams from CWA jurisdiction as those features are more appropriately
                regulated by States and Tribes under their sovereign authorities.
                However, the agencies have modified the final rule to reduce the
                instances in which natural and artificial features and structures sever
                jurisdiction of upstream waters, as discussed in Section III.A.3 and in
                more detail below. The agencies conclude that interpreting upstream
                waters that contribute surface water flow in a typical year to a
                paragraph (a)(1) water to be part of the regulated tributary network
                better balances the CWA's objective in section 101(a) with the need to
                respect State and tribal authority over land and water resources as
                mandated by Congress in section 101(b).
                2. Summary of Final Rule Rationale and Public Comment
                 The definition of ``tributary'' in the final rule reflects the
                authority granted by Congress to regulate navigable waters and the
                interconnected nature of the tributary system, as well as the ordinary
                meaning of the term ``waters.'' In addition, the agencies are adhering
                to their constitutional and statutory authority regarding the role of
                the Federal government and limits on its authority to regulate the use
                of land and waters within State and tribal boundaries, and their
                intention to establish a clear and easily implementable definition. The
                definition of ``tributary'' in the final rule sets a boundary on the
                scope of the regulation to ensure that it is consistent with the role
                of the Federal government under the Constitution and the CWA. As the
                Supreme Court recognizes, States traditionally exercise ``primary power
                over land and water use,'' SWANCC, 531 U.S. at 174. The Federal
                government should avoid pressing against the outer limits of its
                authority when doing so would infringe upon the traditional rights and
                responsibilities of States to manage their own waters. See id. at 172-
                73 and supra Section II.E.
                 Under this final rule, a tributary must be perennial or
                intermittent, and it must contribute surface water flow in a typical
                year to a traditional navigable water or territorial sea directly or
                through one or more waters identified in paragraph (a)(2), (3), or (4)
                (generally referred to as ``paragraph (a)(2) through (4) waters'' or
                ``a paragraph (a)(2) through (4) water'' in this notice), or through
                one or more of the features described in Section III.A.3. The
                ``tributary'' category includes waters that, due to their relatively
                permanent flow classifications and their contribution of surface water
                flow to paragraph (a)(1) waters, are appropriately regulated under the
                Commerce Clause powers that Congress exercised when enacting the CWA.
                The agencies have concluded that their regulatory authority under the
                CWA and Supreme Court precedent is most appropriately interpreted to
                encompass the perennial and intermittent flow classifications provided
                in the definition of ``tributary,'' and that this approach also
                balances the regulation of the Federal government with the authority of
                States and Tribes to more appropriately regulate certain waters within
                their jurisdiction, such as ephemeral streams. The agencies have also
                concluded that this definition effectively furthers both the objective
                of the Act to ``restore and maintain the chemical, physical, and
                biological integrity of the nation's waters'' and the ``policy of
                Congress to recognize, preserve, and protect the primary
                responsibilities and rights of States to prevent, reduce, and eliminate
                pollution [and] to plan for the development and
                [[Page 22288]]
                use (including restoration, preservation, and enhancement) of land and
                water resources . . . .'' 33 U.S.C. 1251(b); see also Rapanos, 547 U.S.
                at 737 (Scalia, J., plurality). The agencies' approach to defining
                ``tributary'' is also intended to ensure that federal regulatory
                jurisdiction does not intrude upon State, tribal, and local control of
                land and water use decisions. See Rapanos, 547 U.S. at 738 (Scalia, J.,
                plurality) (``Regulation of land use, as through the issuance of the
                development permits . . . is a quintessential state and local
                power.''). With this final definition, the agencies seek to avoid
                ``impairing or in any manner affecting any right or jurisdiction of the
                States with respect to the waters (including boundary waters) of such
                States.'' 33 U.S.C. 1370.
                 A clear regulatory line between jurisdictional and excluded waters
                has the additional benefit of being less complicated than prior
                regulatory regimes that required a case-specific significant nexus
                analysis. Ephemeral features, such as dry washes and arroyos, that lack
                the perennial or intermittent flow necessary to satisfy the
                ``tributary'' definition under this final rule are excluded from the
                definition. Although the agencies are not regulating features that flow
                only in direct response to precipitation, certain ephemeral features
                can convey surface water flow that is sufficient to maintain the
                jurisdictional status of the upstream tributary reach, as discussed in
                Section III.A.3. States and Tribes may also address ephemeral features
                as ``waters of the State'' or ``waters of the Tribe'' under their own
                laws to the extent they deem appropriate, as envisioned under section
                101(b) of the CWA. In addition, an ephemeral feature may convey a
                discharge of pollutants from a point source to a water of the United
                States. See Rapanos, 547 U.S. at 743-44 (Scalia, J., plurality).
                 Some commenters stated that the agencies' proposal for tributaries
                is not supported by science and is inconsistent with the CWA and
                judicial precedent. The agencies disagree. As discussed in the preamble
                to the proposed rule, the agencies relied on the available science to
                help inform where to draw the line of federal jurisdiction over
                tributaries, consistent with their statutory authorities. See 84 FR
                4175 (``This proposed definition [of tributary] is also informed by the
                science.'') As noted in that preamble, while the SAB found that the
                draft Connectivity Report ``provides strong scientific support for the
                conclusion that ephemeral, intermittent, and perennial streams exert a
                strong influence on the character and functioning of downstream waters
                and that tributary streams are connected to downstream waters,'' the
                SAB stressed that ``the EPA should recognize that there is a gradient
                of connectivity.'' SAB Review at 3. The SAB recommended that ``the
                interpretation of connectivity be revised to reflect a gradient
                approach that recognizes variation in the frequency, duration,
                magnitude, predictability, and consequences of physical, chemical, and
                biological connections.'' Id. at 2 (emphasis added). To describe the
                ``connectivity gradient'' and the probability that impacts occurring
                along the gradient will be transmitted downstream, the SAB developed a
                figure as part of its review of the Draft Connectivity Report. See id.
                at 54 figure 3. The figure illustrates the connectivity gradient and
                potential consequences between perennial, intermittent, and ephemeral
                streams and downstream waters and depicts a decreased ``probability
                that changes . . . will be transmitted to downstream waters'' at flow
                regimes less than perennial and intermittent. Id. While the SAB stated
                that ``at sufficiently large spatial and temporal scales, all waters
                and wetlands are connected,'' it found that ``[m]ore important are the
                degree of connection (e.g., frequency, magnitude, timing, duration) and
                the extent to which those connections affect the chemical, physical,
                and biological integrity of downstream waters.'' Id. at 17.
                 The SAB, however, recognized that ``[t]he Report is a science, not
                policy, document that was written to summarize the current
                understanding of connectivity or isolation of streams and wetlands
                relative to large water bodies such as rivers, lakes, estuaries, and
                oceans.'' id. at 2. ``The SAB also recommended that the agencies
                clarify in the preamble to the final rule that `significant nexus' is a
                legal term, not a scientific one.'' 80 FR 37065. And in issuing the
                2015 Rule, the agencies stated, ``the science does not provide a
                precise point along the continuum at which waters provide only
                speculative or insubstantial functions to downstream waters.'' Id. at
                37090. Thus, the agencies use the Connectivity Report to inform certain
                aspects of the revised definition of ``waters of the United States,''
                such as recognizing the ``connectivity gradient'' and potential
                consequences between perennial, intermittent, and ephemeral streams and
                downstream waters within a tributary system. The ``tributary''
                definition that the agencies are finalizing, which takes into
                consideration the connectivity gradient, ``rests upon a reasonable
                inference of ecological interconnection'' between those tributaries and
                paragraph (a)(1) waters. 547 U.S. at 780 (Kennedy, J., concurring in
                the judgment). The agencies acknowledge that science alone cannot
                dictate where to draw the line between Federal and State waters, as
                those are legal distinctions that have been established within the
                overall framework and construct of the CWA.
                 The agencies also relied on scientific principles, as appropriate
                and within the agencies' statutory limits, to inform several other
                aspects of this final rule, including, for example, how the agencies
                define the flow classifications (perennial, intermittent, ephemeral)
                used throughout the regulation, the incorporation of inundation and
                flooding to create surface water connections, and the use of the
                typical year concept that relies upon a large body of precipitation and
                other climatic data to inform what may be within a normal range for a
                particular geographic region. The agencies will also rely on science to
                implement the final rule, such as with the development of tools and
                scientific-based approaches to identify flow classification and typical
                year conditions.
                 Thus, contrary to the assertions of some commenters, the agencies'
                decisions in support of this final rule have been informed by science.
                The agencies therefore agree with other commenters who stated that the
                agencies appropriately balanced science, policy, and the law when
                crafting the proposed rule. But to be clear, as discussed in the
                preamble to the proposed rule, 84 FR 4176, and in Section II.E of this
                notice, science cannot dictate where to draw the line between Federal
                and State or tribal waters, as those are legal distinctions that have
                been established within the overall framework and construct of the CWA.
                The definition of ``waters of the United States'' must be grounded in a
                legal analysis of the limits on CWA jurisdiction reflected in the
                statute and Supreme Court guidance.
                 By defining perennial and intermittent tributaries of traditional
                navigable waters as jurisdictional and ephemeral features as non-
                jurisdictional, the agencies balance Congress' intent to interpret the
                term ``navigable waters'' more broadly than the classical understanding
                of that term, see Riverside Bayview, 474 U.S. at 133, with the fact
                that nothing in the legislative history of the Act ``signifies that
                Congress intended to exert anything more than its commerce power over
                navigation.'' SWANCC, 531 U.S. at 168 n.3. The final rule's definition
                of ``tributary'' is also consistent with the Rapanos plurality's
                position that `` `the
                [[Page 22289]]
                waters of the United States' include only relatively permanent,
                standing, or flowing bodies of waters . . . as opposed to ordinarily
                dry channels . . . or ephemeral flows of water.'' Rapanos, 547 U.S. at
                732-33 see also id. at 736 n.7 (``[R]elatively continuous flow is a
                necessary condition for qualification as a `water,' not an adequate
                condition'' (emphasis in original)). Perennial waters, by definition,
                are permanent. And while the plurality did note that waters of the
                United States do not include ``ordinarily dry channels through which
                water occasionally or intermittently flows,'' id. at 733, the plurality
                would ``not necessarily exclude seasonal rivers, which contain
                continuous flow during some months of the year but no flow during dry
                months.'' Id. at 732 n.5 (emphasis in original); compare id. at 770
                (Kennedy, J., concurring in the judgment) (``an intermittent flow can
                constitute a stream . . . while it is flowing . . . [i]t follows that
                the Corps can reasonably interpret the Act to cover the paths of such
                impermanent streams''). The agencies note that intermittent waters may
                occur seasonally, for example, during times when groundwater tables are
                elevated or when snowpack runoff produces relatively permanent flow,
                returning on an annual basis in known, fixed geographic locations.
                 By defining ``tributary'' as perennial or intermittent rivers and
                streams that contribute surface water flow to traditional navigable
                waters or the territorial seas in a typical year, the agencies are
                establishing that a mere hydrologic connection cannot provide the basis
                for CWA jurisdiction; the bodies of water must be ``geographical
                features'' (i.e., rivers and streams) that are ``relatively permanent''
                (i.e., perennial or intermittent) and that contribute surface water
                flow to a traditional navigable water or the territorial seas in a
                typical year. Rapanos, 547 U.S. at 732. This requirement is informed by
                Rapanos, wherein the plurality determined that the phrase ``the waters
                of the United States'' ``cannot bear the expansive meaning that the
                Corps would give it,'' id. at 732, and challenged the notion that
                ``even the most insubstantial hydrologic connection may be held to
                constitute a `significant nexus.' '' Id. at 728. Similarly, Justice
                Kennedy noted, ``mere hydrologic connection should not suffice in all
                cases; the connection may be too insubstantial for the hydrologic
                linkage to establish the required nexus with navigable waters as
                traditionally understood.'' Id. at 784-85. The agencies believe that
                the requirement that a tributary be perennial or intermittent and be
                connected to a traditional navigable water is reasonable and reflects
                the plurality's description of a `` `wate[r] of the United States' ''
                as ``i.e., a relatively permanent body of water connected to
                traditional interstate navigable waters.'' Id. at 742.
                 Under the proposed definition of ``tributary,'' an artificial or
                natural ephemeral feature would have severed jurisdiction upstream of
                the feature, because the waterbody would not contribute surface water
                to a paragraph (a)(1) water on a perennial or intermittent basis.
                Several commenters supported this approach, noting that waters above
                ephemeral breaks are more appropriately subject to State or tribal
                jurisdiction. Others criticized the approach as too restrictive and
                raised concerns regarding the importance of those upstream waters to
                the tributary system. The agencies recognize that the proposed rule's
                treatment of ephemeral features would have severed jurisdiction for
                certain relatively permanent bodies of water that are regularly
                ``connected to'' traditional navigable waters in a typical year via
                channelized surface water flow through those features. The final rule
                has been modified to address these concerns regarding ephemeral breaks
                between two relatively permanent waters while remaining faithful to the
                text, structure, and legislative history of the CWA and Supreme Court
                guidance.
                 As discussed in Section III.A.3, the final rule provides that
                channelized non-jurisdictional surface water features do not sever
                jurisdiction of upstream perennial or intermittent waters so long as
                they convey surface water from such upstream waters to downstream
                jurisdictional waters in a typical year. The use of ``channelized'' in
                this context generally indicates features with a defined path or
                course, such as a ditch or the bed of an ephemeral stream. The flow
                must be channelized in the sense of being discrete and confined to a
                channel, as opposed to diffuse, non-channelized flow. Channelized non-
                jurisdictional surface water features are generally continuously
                present on the landscape as geomorphic features and may regularly
                ``connect'' the upstream tributary to the downstream jurisdictional
                water such that those waters can mix and become indistinguishable in a
                typical year. This may occur, for example, where managed water systems
                alter the flow classification of a perennial or intermittent tributary
                to ephemeral but the perennial or intermittent flow returns farther
                downstream. It could also occur as a result of natural conditions, such
                as a tributary that becomes a losing stream for a reach, but then
                becomes perennial again downstream of the losing reach. The losing
                reach could occur because of water infiltrating into the ground and
                recharging groundwater, where the water table is below the bottom of
                the channel bed.
                 The final rule also allows for other types of artificial or natural
                features, such as dams or boulder fields, which may maintain
                jurisdiction so long as they convey surface water flow from an upstream
                tributary to a downstream jurisdictional water in a typical year. The
                agencies have determined in this final rule that such conditions do not
                sever jurisdiction for the upstream reach of the tributary if a
                channelized non-jurisdictional surface water feature conveys surface
                water flow to a downstream jurisdictional water in a typical year. The
                agencies have concluded that water flowing through features such as
                dams or boulder fields can sustain a regular and predictable surface
                water connection between upstream and downstream waters and therefore
                can maintain jurisdiction between such waters. In all cases, however,
                the excluded or ephemeral feature remains non-jurisdictional. Certain
                other excluded features are incapable of providing channelized surface
                flow (e.g., groundwater, diffuse stormwater run-off, or directional
                sheet flow over upland) and therefore sever jurisdiction upstream of
                such excluded features.
                 The Supreme Court has not spoken directly to the question of
                whether an ephemeral reach along or downstream of an otherwise
                jurisdictional tributary severs jurisdiction, and the agencies believe
                that the final rule appropriately reflects their statutory authority.
                In particular, the plurality decision in Rapanos emphasized that
                jurisdictional waters themselves must be relatively permanent and
                connected to traditional navigable waters, 547 U.S. at 742, but did not
                specify the type of connection necessary between the relatively
                permanent waters and downstream traditional navigable waters. Justice
                Kennedy's opinion stated that the Corps could identify by regulation
                categories of tributaries based on ``their volume of flow (either
                annually or on average), their proximity to navigable waters, or other
                relevant considerations,'' id. at 780-81, but fails to provide further
                guidance. The agencies conclude that the final rule appropriately
                reflects and balances these general guiding principles by exercising
                jurisdiction over perennial and intermittent tributaries but not
                ephemeral streams
                [[Page 22290]]
                and dry washes, while under certain circumstances allowing such
                channelized features to maintain jurisdiction between upstream and
                downstream more permanent waters.
                 Some commenters agreed with the agencies' proposal that ephemeral
                reaches should sever jurisdiction of upstream waters because those
                waters no longer have a continuous hydrologic surface connection of
                relatively permanent flow to a downstream jurisdictional water. Other
                commenters stated that the proposed definition of ``waters of the
                United States'' was inconsistent in that some forms of natural or
                artificial features could connect upstream tributaries with downstream
                jurisdictional waters, whereas ephemeral reaches would have severed
                jurisdiction of upstream perennial and intermittent streams. In
                addition, many commenters raised concerns about implementing a
                definition of ``tributary'' in which an ephemeral feature would sever
                jurisdiction of upstream reaches, indicating that it may be difficult
                to apply in the field. Commenters also stated that if ephemeral
                features severed jurisdiction of perennial and intermittent waters
                upstream, many waters in certain regions, such as the arid West, would
                be non-jurisdictional. Some commenters expressed concern that the
                proposed definition would place a burden on project applicants to
                identify and anticipate such ephemeral breaks to avoid potential
                responsibility for compensatory mitigation of upstream losses. The
                agencies have modified the final rule language in a manner that
                addresses these concerns. Under the final rule, tributaries that
                contribute surface water flow to a downstream jurisdictional water in a
                typical year through certain natural features (such as debris piles or
                boulder fields) or artificial features (such as culverts or dams) are
                tributaries, even though these features may result in an interruption
                in the surface water channel. A perennial or intermittent tributary
                above the natural or artificial feature does not lose its
                jurisdictional status as long as the natural or artificial feature
                continues to convey surface water flow from the upstream reach to a
                downstream jurisdictional water in a typical year.
                 Commenters also requested clarification on whether a natural
                feature through which a tributary flows could be considered a
                jurisdictional feature as part of the tributary itself, such as a
                boulder field or subterranean river. Natural or artificial features
                that do not satisfy the surface water flow conditions of the
                ``tributary'' definition are not tributaries under this rule, even if
                they convey surface water flow from upstream relatively permanent
                waters to downstream jurisdictional waters in a typical year. See
                Section III.A.3 for additional discussion.
                 Some commenters asked for clarification on whether tributaries are
                viewed as reaches or as an entire network. The agencies are using the
                term ``reach'' in this preamble to the final rule to mean a section of
                a stream or river along which similar hydrologic conditions exist, such
                as discharge, depth, area, and slope.\45\ If a perennial tributary
                becomes intermittent and then ephemeral and then perennial again, it
                may be viewed as four separate reaches (e.g., perennial reach,
                intermittent reach, ephemeral reach, perennial reach), especially if
                they also share other similarities with respect to depth, slope, or
                other factors. In general, a reach can be any length of a stream or
                river, but the agencies are clarifying for implementation purposes that
                such length is bounded by similar flow characteristics.
                ---------------------------------------------------------------------------
                 \45\ See Connectivity Report at A-10, defining ``reach'' as ``a
                length of stream channel with relatively uniform discharge, depth,
                area, and slope.'' A similar definition is used by the USGS, at
                https://www.usgs.gov/faqs/what-a-reach.
                ---------------------------------------------------------------------------
                 Commenters suggested that flow classification and jurisdictional
                status could be determined based on the flow in the majority of a reach
                (i.e., whether it is perennial, intermittent, and ephemeral), which
                they said would be simpler than differentiating various segments from
                the broader stream reach. The agencies are not determining flow
                classification using the majority of the reach. Under the Rapanos
                Guidance, a tributary ``reach'' was identified by a stream order
                classification system where the relevant reach was used for purposes of
                a significant nexus determination. However, stream order is not
                directly relevant to stream and river jurisdiction under this final
                rule, and instead flow classification is a key aspect in determining
                the jurisdictional status of a tributary. The agencies conclude that
                such an approach is easier to implement in light of the final rule's
                ``tributary'' definition and is more consistent with the legal and
                scientific foundation for the rule. Along the length of a tributary,
                the flow classification may fluctuate, and the points at which flow
                classifications change are the points at which a reach is bounded. If a
                tributary flows through a non-jurisdictional ephemeral reach to
                downstream jurisdictional waters, the point at which a tributary
                becomes ephemeral may fluctuate upstream and downstream in a typical
                year based on climatic conditions, changes in topography and
                surrounding development, water input, and water withdrawals. When such
                a transition zone of flow classification occurs, the agencies will use
                best professional judgment and various tools to identify where the
                change in flow classification occurs. The agencies have historically
                implemented comparable approaches at transition zones, for example with
                the identification of the extent of tidal influence (also referred to
                as the head of tide). This generally occurs where a river flows into
                tidal waters and the agencies must identify the farthest point upstream
                where a tributary is affected by tidal fluctuations in order to
                determine which lateral extent to apply for the limits of jurisdiction
                (i.e., high tide line or ordinary high water mark), permitting
                requirements, and similar factors. There is generally not a hard
                demarcation distinguishing where a waterbody ceases to be tidal, so the
                agencies must use best professional judgment utilizing all available
                information and tools which may assist in making the determination. See
                Section III.B.3 for additional information.
                 Many commenters recommended that tributaries that were altered or
                relocated should remain tributaries. The agencies agree with those
                comments and, consistent with the proposal, have included that
                provision in the final rule. Many commenters expressed concern about
                the challenges of implementing a flow-based ``tributary'' definition
                where many systems have been modified by human actions. Some commenters
                also stated that the use of ``naturally occurring'' in the proposed
                ``tributary'' definition was unclear and questioned how it would apply
                to modified systems. The agencies disagree with the proposition that
                identifying flow conditions would be challenging in modified systems.
                An altered tributary is one in which the flow or geomorphic conditions
                have been modified in some way, for example, by straightening a sinuous
                tributary, adding concrete or riprap to stabilize the banks of a
                tributary, reducing flow conditions from perennial to intermittent flow
                due to water withdrawals, or widening or adding physical features (such
                as riffle/pool complex restoration or check dams) to the tributary to
                reduce the velocity of flow. A relocated tributary is one in which an
                entire portion of the tributary may be moved to a different location,
                as when a tributary is rerouted around a city center to protect it from
                flooding or around a mining complex to enable extraction of
                commercially
                [[Page 22291]]
                valuable minerals. To be considered a tributary, such features must
                continue to meet the flow conditions of the ``tributary'' definition.
                The agencies conclude that identifying flow conditions in these
                features would be no more challenging than identifying flow conditions
                in other tributaries, which the agencies have been doing to apply the
                Rapanos Guidance since 2008. In a relocated tributary, the reach that
                has been relocated may meet the definition of ``ditch'' or may be
                colloquially called a ditch, which is why, for simplicity and clarity,
                the agencies have included these ditches in the definition of
                ``tributary.'' The agencies also believe that retaining jurisdiction
                over the relocated tributary is consistent with its legal authorities
                and the agencies' treatment of impoundments of jurisdictional waters
                (see Section III.F), which may alter the course or form of a water of
                the United States but maintains sufficient surface water connection to
                a traditional navigable water in a typical year.
                 Some commenters requested clarification on how water diversions may
                affect the jurisdictional status of tributaries. A water diversion that
                completely reroutes a tributary through a tunnel would be considered an
                artificial feature that would not sever jurisdiction under this final
                rule. The tunnel itself is not a tributary under the rule, however,
                because it is not a surface water channel. This final rule clarifies
                that jurisdiction applies based on current flow classification in a
                typical year. When completing jurisdictional determinations in managed
                systems, just as in natural systems, the agencies will consider whether
                features meet the flow conditions of the ``tributary'' definition in a
                typical year. Managed systems are jurisdictional as long as they
                satisfy the definition of ``tributary,'' including the flow conditions.
                If a stream is ephemeral in a typical year due to managed water
                withdrawals, the feature is an excluded ephemeral stream. Tributaries
                that have been altered via water management systems, or whose
                morphology has been altered in some manner, maintain their tributary
                status as long as they are perennial or intermittent and contribute
                surface water flow to the territorial seas or a traditional navigable
                water in a typical year.
                 Under the pre-existing regulatory regime (recodified in the 2019
                Rule), the agencies conducted a significant nexus analysis for certain
                types of waters referred to as ``non-relatively permanent waters,''
                which includes ephemeral features and some intermittent streams. See
                Rapanos Guidance at 7 (`` `[R]elatively permanent' waters do not
                include ephemeral tributaries which flow only in response to
                precipitation and intermittent streams which do not typically flow
                year-round or have continuous flow at least seasonally. However, CWA
                jurisdiction over these waters will be evaluated under the significant
                nexus standard[.]''). The definition of ``tributary'' in the final rule
                replaces existing procedures that utilize a case-specific ``significant
                nexus'' analyses of the relationship between a particular stream and
                downstream traditional navigable water. The agencies are eliminating
                this case-specific ``significant nexus'' analysis by providing a clear
                definition of ``tributary'' that is easier to implement. Justice
                Kennedy's ``significant nexus'' test for wetlands adjacent to
                nonnavigable tributaries was needed only ``absent more specific
                regulations,'' Rapanos, 547 U.S. at 782, because ``the breadth of [the
                Corps' existing tributary] standard . . . seems to leave wide room for
                regulation of drains, ditches, and streams remote from any navigable-
                in-fact water and carrying only minor water volumes towards it'' and
                thus ``precludes its adoption as the determinative measure of whether
                adjacent wetlands are likely to play an important role in the integrity
                of an aquatic system comprising navigable waters as traditionally
                understood.'' Id. at 781. In light of the ``more specific [tributary]
                regulations'' finalized in this rule, the agencies are eliminating the
                case-specific significant nexus review through categorical treatment,
                as ``waters of the United States,'' of all tributaries with perennial
                or intermittent flow that contribute surface water flow to downstream
                navigable-in-fact waters in a typical year. See id. at 780-81 (Kennedy,
                J., concurring in the judgment) (``Through regulations or adjudication,
                the Corps may choose to identify categories of tributaries that, due to
                their volume of flow (either annually or on average), their proximity
                to navigable waters, or other relevant considerations, are significant
                enough that wetlands adjacent to them are likely, in the majority of
                cases, to perform important functions for an aquatic system
                incorporating navigable waters.'') (emphasis added). In doing so, the
                agencies believe they avoid interpretations of the CWA that raise
                significant constitutional questions. See id. at 738 (plurality)
                (``Even if the term `the waters of the United States' were ambiguous as
                applied to channels that sometimes host ephemeral flows of water (which
                it is not), we would expect a clearer statement from Congress to
                authorize an agency theory of jurisdiction that presses the envelope of
                constitutional validity.'').
                 The agencies recognize that this is a departure from prior
                positions of the Federal government. The agencies also recognize that
                prior to the finalization of this rule, some courts applied the
                significant nexus standard articulated in Justice Kennedy's opinion as
                the exclusive test of CWA jurisdiction over certain waters. As
                described in detail in Section II.E, the agencies have analyzed the
                text, structure, and legislative history of the CWA in light of Supreme
                Court guidance and conclude that this final rule incorporates important
                aspects of Justice Kennedy's opinion, together with those of the
                plurality, to craft a clear and implementable definition that stays
                within their statutory and constitutional authorities.
                 The final ``tributary'' definition contains no flow volume
                requirement, but only a requirement of perennial or intermittent flow
                and a contribution of surface water flow to a paragraph (a)(1) water in
                a typical year. The agencies believe that establishing a specific flow
                volume requirement for all tributaries is inappropriate, given the wide
                spatial and temporal variability of flow volume in rivers and streams
                across the country. While the definition may in certain instances
                assert jurisdiction over bodies of water contributing ``the merest
                trickle,'' 547 U.S. at 769 (Kennedy, J., concurring in the judgment),
                to a traditional navigable water during certain times of the year, the
                agencies conclude that such bodies are `` `waters' in the ordinary
                sense of containing a relatively permanent flow'' regardless of flow
                volume. Id. at 757 (Scalia, J., plurality).
                 Some commenters suggested that using stream flow volumes rather
                than flow duration classifications for the definition of ``tributary''
                would be easier to implement. The agencies disagree with this
                suggestion based on their experience. In 1977, the Corps proposed to
                use flow volumes (i.e., five cubic feet per second) to define
                ``headwaters'' in the definition of ``waters of the United States,''
                and instead finalized the use of flow volumes for implementation of
                their general permit program. 42 FR 37129 (July 19, 1977). Stream flow
                volume is challenging to measure directly, in particular in an
                intermittent stream where flow is not always present and may require
                multiple field-based measurements that can make implementation
                inefficient and result in delays in making a jurisdictional
                determination. While flow duration classifications may also require
                field measurements, in certain instances
                [[Page 22292]]
                remote tools, such as remote sensing and aerial photography, can be
                used to observe presence or absence of flow and identify flow duration
                classifications, but cannot also assess flow volumes. In addition, the
                agencies have not identified a reasonable or appropriate rationale or
                justification for specific flow volumes that should establish
                jurisdiction given the broad nationwide applicability of the final
                rule.
                 A few commenters requested a flow duration metric (e.g., 30, 90, or
                185 days) to determine a jurisdictional tributary. Several commenters
                recommended the agencies adopt a definition of ``intermittent'' that
                contains the requirement of continuous flow for a specific duration,
                such as ``at least one month of the calendar year'' to provide
                certainty for determining flow classification. See e.g., 30 CFR 710.5
                (definition of ``intermittent'' used in a U.S. Department of Interior
                regulation). Several commenters also recommended a regionalized
                approach to flow classification. The agencies have finalized an
                approach that considers streamflow duration in the flow classification
                definitions generally (e.g., ``flowing continuously year-round,''
                ``flowing continuously during certain times of the year and more than
                in direct response to precipitation,'' and ``flowing . . . only in
                response to precipitation'') but without specifying an exact number of
                days of flow. The agencies are not providing a specific duration (e.g.,
                the number of days, weeks, or months) of surface flow that constitutes
                intermittent flow, as the time period that encompasses intermittent
                flow can vary widely across the country based upon climate, hydrology,
                topography, soils, and other conditions. The ``typical year'' construct
                captures that variability, however, and provides for regional and local
                variations in the actual application of a uniform nationwide
                definition. The agencies acknowledge that an approach utilizing a
                specific duration would provide for enhanced national consistency, but
                it would also undermine the regionalized implementation of intermittent
                tributaries as provided for under this final rule. Some commenters
                cautioned the agencies against treating intermittent streams similarly
                across the country based on a prescriptive flow duration metric, as
                intermittent streams in the arid West are fundamentally different from
                intermittent streams in the Southeast, for example. A specific duration
                requirement would also be challenging to implement--even landowners
                familiar with their properties may not know the number of days a stream
                flows per year.
                 Other commenters recommended the use of physical indicators of
                flow, such as ordinary high water mark and bed and banks, which could
                be regionalized for a field-based approach. These commenters stated
                that physical indicators can be more readily observable and can
                indicate flows of sufficient magnitude and duration to qualify as a
                tributary. The agencies disagree with these comments and conclude that
                physical indicators of flow, absent verification of the actual
                occurrence of flow, may not accurately represent the flow
                classifications required for tributaries under this rule. See, e.g.,
                547 U.S at 781 (Kennedy, J., concurring in the judgment) (expressing
                concerns that a the Corps' existing tributary standard based, in part,
                on the ``possess[ing]'' of ``an ordinary high water mark, defined as a
                `line on the shore established by the fluctuations of water and
                indicated by [certain] physical characteristics,' . . . seems to leave
                wide room for regulation of drains, ditches, and streams remote from
                any navigable-in-fact water and carrying only minor water volumes
                towards it''). For example, ephemeral streams can have an ordinary high
                water mark and bed and banks, which would not allow for the agencies or
                the public to distinguish between a non-jurisdictional ephemeral stream
                and a jurisdictional intermittent or perennial tributary using those
                physical indicators. Ephemeral streams in the arid West, for example,
                may have ordinary high water marks that were incised years ago
                following a single large storm. It makes more practical sense for a
                feature to be first assessed as a tributary, after which the lateral
                extent of that tributary can be identified using the ordinary high
                water mark.
                 Physical indicators, however, may be one line of evidence the
                agencies could use to evaluate whether a stream meets the flow
                requirements to be a tributary under this definition. These indicators
                could be regionalized to obtain a practical field-based approach for
                identifying the flow classification of a stream which is a required
                component of identifying a tributary. Such physical indicators are
                further discussed in Section III.D.3 of this notice. In addition, the
                agencies cannot always rely on field-based physical indicator methods--
                for example, when evaluating a site at a time that does not meet the
                definition of ``typical year.'' In some instances, completing a desktop
                determination with remote tools may supplement or substitute for field-
                based indicators.
                3. How will the agencies implement the final rule?
                 The agencies will employ many different methods and tools to
                identify and determine whether a feature meets the definition of
                ``tributary'' under this final rule. A few commenters recommended that
                the agencies identify a variety of methods which may be employed to
                identify flow classifications, and that such methods involve tools
                readily available to a typical landowner. Methods and tools used by the
                agencies are generally available for the public to use so that they can
                make an informed decision about how to proceed with requests for
                jurisdictional determinations or authorization for activities under the
                CWA. The agencies believe that there are numerous cases where an
                informed decision can save valuable time and money by avoiding
                unnecessary jurisdictional determination requests. This can be done,
                for example, where landowners are familiar with the water features on
                their property and know that they only flow in response to a rain
                event, or that an isolated wetland in the middle of a ranch is not
                flooded by a nearby perennial river in a typical year. However, in
                cases where a member of the general public makes an informed decision
                to not request a jurisdictional determination and discharges pollutants
                into a waterbody that is, in fact, jurisdictional without required
                permits, the individual could be subject to the agencies' enforcement
                authorities under the CWA.
                 One of the first steps in determining whether a feature is a
                tributary is to identify relevant features on the landscape, such as
                rivers, streams, or similar naturally occurring surface water channels,
                as well as ditches. Field work to include direct observation and other
                reliable methods can indicate the existence of a tributary, such as
                stream gage data, elevation data, historic or current water flow
                records, flood predictions, statistical evidence, aerial imagery, and
                USGS maps.
                 Another step in determining whether a feature is a tributary is to
                identify whether the feature contributes surface water flow to a
                paragraph (a)(1) water either directly or through one or more paragraph
                (a)(2) through (4) waters in a typical year. The agencies intend to use
                several sources to identify the flow path of a potential tributary to
                determine whether surface water flow is being contributed eventually to
                a paragraph (a)(1) water. The agencies can use USGS maps, State and
                local knowledge or maps, aerial photography, or other remote sensing
                information so long as
                [[Page 22293]]
                the tools the agencies use have been verified to be reliable (see,
                e.g., Section IV of this notice regarding limitations of existing
                aquatic resource mapping datasets) to assess a feature's flow path. The
                agencies can also use available models, including models developed by
                Federal, State, tribal and local governments, academia, and the
                regulated community. One such model includes the ``Flow (Raindrop)
                Path'' GIS tool which allows the user to click a point on a map to
                signify a falling raindrop on that point, after which a flow path is
                drawn to estimate where the raindrop may flow, eventually making its
                way to the ocean if the tributary network allows for it (https://streamstats.usgs.gov/ss/). The StreamStats tool may potentially be used
                to identify the flow path from the subject water to the downstream
                paragraph (a)(1) water using the ``Flow (Raindrop) Path'' component of
                the tool. These tools could be used in conjunction with field
                observations, data, and other desktop tools to evaluate whether a
                specific point on a potential tributary may have a surface water
                connection to a downstream paragraph (a)(1) water in a typical year.
                 In addition to identifying the presence of rivers, streams, or
                similar naturally occurring surface water channels which contribute
                surface water flow to a downstream paragraph (a)(1) water, the agencies
                must assess the feature's flow classification. The agencies have
                substantial experience using visual hydrologic observations, field data
                and indicators, and remote tools to determine flow classification.
                Commenters expressed several key concerns about the flow classification
                concept. Some commenters noted that there is no established or
                universally accepted methodology to identify flow classification. The
                agencies agree that there is no universally accepted methodology;
                however, scientists, environmental consultants, and other water
                resource professionals, including agency staff, have used the terms
                ``perennial,'' ``intermittent,'' and ``ephemeral'' for decades in the
                field. Indeed, the agencies have used these terms to evaluate the
                jurisdictional status of waters for more than a decade, in accordance
                with the 2008 Rapanos Guidance.\46\ More recently, the Corps has
                applied these terms in its Nationwide Permit Program (NWP). See 82 FR
                1860, 2005 (January 6, 2017). The terms are used in the NWP in a manner
                similar to the definitions in this final rule, but in the NWP the terms
                adhere more closely to the generally-accepted scientific definitions
                that focus on groundwater rising above the bed of the stream channel as
                differentiating between ephemeral features and perennial and
                intermittent waters. See id. at 2006. For the reasons explained in
                Section III.A.2, however, the agencies have finalized definitions for
                the three flow classification terms in this rule that better align with
                the scope of CWA jurisdiction, while improving clarity of the rule and
                transparency of the agencies' implementation. These flow classification
                terms can be implemented using readily available resources in addition
                to visual assessments.
                ---------------------------------------------------------------------------
                 \46\ Under the Rapanos Guidance, the agencies applied a
                different jurisdictional test based upon a tributary's flow regime.
                ``The agencies will assert jurisdiction over relatively permanent
                non-navigable tributaries of traditional navigable waters without a
                legal obligation to make a significant nexus finding.'' Rapanos
                Guidance at 7. Relatively permanent tributaries were described in
                the guidance as tributaries that ``typically flow year-round or have
                continuous flow at least seasonally (e.g., typically three
                months)[.]'' Id. at 1. At the same time, the guidance established
                that `` `relatively permanent' waters do not include ephemeral
                tributaries which flow only in response to precipitation and
                intermittent streams which do not typically flow year-round or have
                continuous flow at least seasonally. . . . CWA jurisdiction over
                these waters will be evaluated under the significant nexus [test.]''
                Id. at 7. The agencies also note that in June 2009, the Corps added
                a classification code ``R6,'' entitled ``Riverine Ephemeral,'' to
                identify ephemeral aquatic resources. The Corps created the ``R6''
                code to provide clarity to field staff when identifying ephemeral
                waters for entry into the ORM2 database. See https://www.spa.usace.army.mil/Portals/16/docs/civilworks/regulatory/Bulk%20Upload/Bulk%20Data%20Cowardin.pdf.
                ---------------------------------------------------------------------------
                 Some commenters expressed concern that the information needed to
                determine flow classification would require a high burden of proof and
                would result in significantly longer processing times for
                jurisdictional determinations. The agencies will continue to bear the
                burden of proof for determinations and, as noted above, have already
                implemented a version of the flow classification concept under the
                Rapanos Guidance and the Corps' NWP. The agencies disagree with the
                suggestion that the use of these flow classifications will result in a
                lengthier process for jurisdictional determinations. With the clear and
                categorical definition as to the scope of CWA jurisdiction included in
                this final rule, the elimination of the significant nexus determination
                requirement for tributaries, the use of existing tools, and the
                development of new tools, jurisdictional determinations for tributaries
                should be more efficient under this final rule than under prior
                regulatory regimes.
                 Some commenters also noted that the data and resources identified
                in the preamble to the proposed rule to evaluate flow classification
                have limited availability. The agencies agree that some data and
                resources have significant limitations and other national-level tools
                and methods may not be readily available or accurate for use in many
                areas of the country, including in rural or remote areas and in heavily
                modified systems. The agencies will continue to rely on local
                knowledge, information provided by the landowner, and local, State, and
                tribal agencies, and a variety of additional tools and resources to
                evaluate flow classification in such systems. The final rule language
                on flow classifications allows for consistent implementation approaches
                for modified systems and more natural systems.
                 Visual observations of surface hydrology are a useful primary
                method to identify flow classifications. The agencies expect that
                landowners will often have sufficient knowledge to understand how water
                moves through their properties, although visual observations could be
                conducted by Federal, State, tribal and local agencies, and other
                public or private organizations, as appropriate. The agencies also
                recognize that a single visual observation may not always be sufficient
                to accurately determine flow classification, and visual observations
                should generally be combined with precipitation and other climate data
                and expected flow seasonality to accurately determine flow
                classification. For example, observing flow directly after a large
                rainfall or observing no flow during a dry season may not be good
                indicators of a stream's typical flow classification.
                 In addition to visual observations of surface hydrology, the
                agencies may use field-based indicators and tools as another line of
                evidence to determine flow classification. Some commenters recommended
                using local flow data collected by government agencies, where
                available, and the agencies acknowledge that this could be a useful
                source of data. The agencies have also used methods such as trapezoidal
                flumes and pressure transducers for measuring surface flow. During the
                public comment period, many commenters mentioned the availability of
                existing rapid, field-based, streamflow duration assessment methods
                that have been developed for use across various States or geographic
                regions and suggested that these existing methods could be used to
                distinguish between streams with perennial, intermittent, and ephemeral
                flow classifications. Many commenters also recommended that the
                agencies develop
                [[Page 22294]]
                similar methods for use across the United States, with input from the
                public and the scientific community.
                 The agencies recognize that some States have developed streamflow
                duration assessment methods (SDAMs) that use physical and biological
                field indicators, such as the presence of hydrophytic vegetation and
                benthic macroinvertebrates, to determine the flow duration class of a
                stream reach as perennial, intermittent, or ephemeral (e.g., the
                Streamflow Methodology for Identification of Intermittent and Perennial
                Streams and Their Origins, developed by the North Carolina Division of
                Water Quality, available at http://portal.ncdenr.org/c/document_library/get_file?uuid=0ddc6ea1-d736-4b55-8e50-169a4476de96&groupId=38364). The EPA, the Corps, and the State of
                Oregon also previously developed a regionalized SDAM that has been
                validated for use throughout the Pacific Northwest since 2015
                (available at http://www.epa.gov/measurements/streamflow-duration-assessment-method-pacific-northwest).
                 Because SDAMs use indicators that are robust to seasonal and short-
                term climatic variability, these methods can be applied in a single
                site visit to distinguish streamflow duration when a channel is flowing
                or in the absence of flow. The agencies agree with commenters that
                these methods are useful and practical tools that could be used to help
                inform timely and predictable jurisdictional determinations, for
                implementation of the final ``tributary'' definition, in the States and
                regions where previously developed SDAMs are available. The agencies
                also agree with commenters that developing similar methods for use
                across the United States would promote consistent implementation of the
                final tributary definition and note that the agencies are currently
                working to develop regionally-specific SDAMs for nationwide coverage.
                The agencies believe that developing regionally-specific SDAMs is
                important to account for the differences in climate, geology, and
                topography that can influence relationships between physical and
                biological indicators and streamflow permanence.
                 A variety of remote, desktop tools could be used to determine flow
                classification of potential tributaries, particularly when coupled with
                site specific information. In meetings with stakeholders, some local
                government officials recommended using local maps developed by
                government agencies, where available, as opposed to national maps,
                noting for example that the National Hydrography Dataset (NHD) has been
                shown to overestimate flow in certain areas. The agencies will assess
                flow classification using a compilation of the best available mapping
                sources, which may include the NHD \47\ or local maps, as well as other
                remote tools such as photographs, StreamStats by the USGS (available at
                https://streamstats.usgs.gov/ss/), Probability of Streamflow Permanence
                (PROSPER) by the USGS (available at https://www.usgs.gov/centers/wy-mt-water/science/probability-streamflow-permanence-prosper), Natural
                Resources Conservation Service (NRCS) hydrologic tools and soil maps,
                desktop tools that provide for the hydrologic estimation of a discharge
                sufficient to generate intermittent or perennial flow (e.g., a regional
                regression analysis or hydrologic modeling), USGS topographic data, or
                modeling tools using drainage area, precipitation data, climate,
                topography, land use, vegetation cover, geology, and/or other publicly
                available information. The agencies will continue to rely on field
                observations and field data to verify desktop assessments as
                appropriate, and will also consider data and tools developed by
                academia, the regulated community, and other stakeholders.
                ---------------------------------------------------------------------------
                 \47\ As described in the RPA for the final rule, the agencies
                note that NHD at High Resolution does not distinguish intermittent
                from ephemeral features in most parts of the country and may not
                accurately identify on-the-ground flow conditions.
                ---------------------------------------------------------------------------
                 Ultimately, multiple data points and multiple sources of
                information should be used to determine flow classification. For
                example, a ``blue line stream'' on a USGS topographic map and/or mapped
                in the NHD may indicate a potential tributary. Combining this
                information with stream order can further inform determinations of flow
                classification, as higher order streams may be more likely to exhibit
                perennial or intermittent flow compared to lower order streams, though
                some headwater streams are perennial or intermittent. The agencies
                could further determine whether flow data, field indicators, or visual
                observations of surface hydrology are available to confirm a stream's
                flow classification. Field-based and remote information may vary in
                availability and accuracy in different parts of the country, so care
                will be taken to evaluate additional information prior to reasonably
                determining the presence or absence of a tributary. Also, the agencies
                will continue to use the specific, validated tools developed by States
                to identify stream flow classifications.
                 As noted previously, the agencies will use best professional
                judgment and various tools to identify where the change in flow
                classification occurs (e.g., from intermittent to ephemeral and vice-
                versa). The tools described above can assist in the identification of
                that transition in flow classification and therefore the delineation of
                a reach as used in this final rule. The primary distinction necessary
                under this rule is the identification of when a perennial or
                intermittent reach transitions to an ephemeral reach and vice-versa.
                The agencies acknowledge that there are spatial and temporal variations
                in stream attributes such that there may not always be a distinct point
                demarcating the flow classification changes. For example, a single
                distinct point may occur at the confluence of two ephemeral streams,
                which become intermittent at the confluence. However, in some
                situations between stream confluences, there may be a transition zone
                where the flow classification change fluctuates within that zone
                throughout a typical year. The agencies will gather information from
                upstream and downstream of the transition zone as far as needed to get
                an accurate assessment of the conditions on the ground when it may be
                necessary for a decision point. This transition zone where the change
                in flow classification occurs will be evaluated by the agencies using
                the tools described above, as well as best professional judgment, to
                identify the most appropriate point at which to distinguish flow
                classifications.
                 In addition to determining the flow classification of a potential
                tributary, the agencies will also determine whether climatic conditions
                are typical to determine whether the water feature meets the definition
                of ``tributary'' under the final rule. As discussed in Section III.A.1,
                the final rule defines the term ``typical year'' to mean ``when
                precipitation and other climatic variables are within the normal
                periodic range (e.g., seasonally, annually) for the geographic area of
                the applicable aquatic resource based on a rolling thirty-year
                period.'' The agencies will use readily available climatic data and
                tools to evaluate normal precipitation and climatic conditions for the
                region at issue and will ensure that the time period of evaluation is
                representative of the normal characteristics of the subject waterbody
                (i.e., it is neither too wet nor too dry). A detailed discussed of how
                the agencies intend to implement this definition is provided in Section
                III.A.1.
                 In utilizing the data sources described above and determining the
                flow classifications of tributaries under typical climatic conditions,
                the agencies recognize the need to consider seasonality and timing of
                tributary
                [[Page 22295]]
                flows. For instance, in some geographic areas, intermittent streams may
                typically flow only at certain times, such as during seasonally wet
                conditions. Thus, the agencies would not expect to observe streamflow
                in seasonally dry conditions, even if precipitation during those dry
                conditions is considered typical for the dates of interest. The
                agencies may need to use the multiple tools described above to
                determine the flow classification for a tributary that is not flowing
                because of seasonally dry conditions, including remote- and field-based
                hydrologic and non-hydrologic indicators of the flow classification
                that would occur during seasonally wet conditions. For example, remote
                indicators might include a series of aerial and satellite images,
                spanning multiple years and taken under normal climatic conditions, the
                majority of which depict water flowing in the channel.
                 In the field, evidence of recent flow can be observed through the
                presence of multiple or abundant signs of certain ordinary high water
                mark indicators for the region, such as the presence of point bars,
                concentrations of drift deposits, or the destruction of terrestrial
                vegetation. Furthermore, certain wetland hydrology indicators can help
                clarify whether water is present in the area only immediately following
                precipitation events, or whether longer-term saturation has likely
                occurred. An example of an indicator is the presence of oxidized
                rhizospheres along living root channels, which can take four to eight
                weeks of continuous saturation to form. This indicator alone cannot be
                conclusive of water flowing above the surface, but multiple positive
                indicators could provide an increased degree of confidence in these
                situations. Conversely, the agencies may observe flow during wetter
                than normal precipitation conditions. In this case, the agencies can
                use other lines of evidence, including remote- and field-based
                hydrologic and non-hydrologic indicators of flow classification as
                appropriate. Streams that contain flowing water during wetter than
                normal climatic conditions, but which lack an ordinary high water mark
                or hydrology indicators may be less likely to flow during normal
                climatic conditions. This assessment is further supported if the
                majority of wet season aerial and satellite images taken during normal
                climatic conditions depict a dry channel. In addition, a landowner's
                specific information indicating whether a water feature meets the
                definition of a ``tributary'' under ``typical year'' conditions may
                also aid in determining flow classification.
                 In addition to requesting clarification about when a surface water
                feature meets the definition of ``tributary,'' some commenters also
                stated that it would be helpful to incorporate the lateral limits of
                jurisdiction directly into the ``tributary'' definition and questioned
                how such limits would be determined. In addition, some commenters
                expressed concern regarding the status of braided rivers that migrate
                and have multiple channels where the jurisdictional limits would be
                identified. The lateral limits of jurisdiction for tributaries extends
                to the ordinary high water mark, as indicated by the physical
                characteristics provided in the definition. Consistent with existing
                practice, the agencies intend to continue to use the Corps' ordinary
                high water mark manuals, as well as Regulatory Guidance Letter 05-05,
                when making ordinary high water mark determinations.\48\ The outer
                limits of a braided channel may be used to identify the lateral extent
                when appropriate, which may encompass multiple low-flow channels and
                the migratory islands that separate them. Adding the ordinary high
                water mark concept to the definition of ``tributary'' is unnecessary
                because it is already located in the Corps' regulations at 33 CFR 328.4
                to identify the lateral extent of jurisdiction. The agencies are
                finalizing the rule with the definition of ``ordinary high water mark''
                as proposed, however, to improve consistency between the corresponding
                regulations and also because the term ``ordinary high water mark'' is
                used in the final rule's definition of ``upland.''
                ---------------------------------------------------------------------------
                 \48\ The Corps' ordinary high water mark manuals are available
                at: https://www.erdc.usace.army.mil/Media/Fact-Sheets/Fact-Sheet-Article-View/Article/486085/ordinary-high-water-mark-ohwm-research-development-and-training/. Regulatory Guidance Letter 05-05 is
                available at: https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll9/id/1253.
                ---------------------------------------------------------------------------
                E. Ditches
                1. What are the agencies finalizing?
                 The regulatory status of ditches has long created confusion for
                farmers, ranchers, irrigation districts, municipalities, water supply
                and stormwater management agencies, and the transportation sector,
                among others. To address this confusion, the agencies proposed to add a
                new category to the definition of ``waters of the United States'' for
                jurisdictional ditches and similar artificial features. The agencies
                proposed to include in that category: (1) Ditches that are traditional
                navigable waters or that are subject to the ebb and flow of the tide
                (e.g., paragraph (a)(1) waters); (2) ditches that are constructed in
                tributaries or that relocate or alter tributaries as long as the ditch
                satisfies the flow conditions of the tributary definition; and (3)
                ditches constructed in adjacent wetlands as long as the ditch likewise
                satisfies the conditions of the tributary definition. 84 FR 4203. All
                other ditches were excluded from CWA jurisdiction under the proposal.
                 Many commenters did not find that the separate jurisdictional
                category of ``ditches'' provided the regulatory clarity and
                predictability that the agencies had sought. They instead stated that
                the separate category created confusion. Other commenters said that the
                proposed separate category provided additional clarity, while others
                argued that all ditches should be excluded. Other commenters stated
                that the proposal was too limiting and should include more ditches as
                jurisdictional, including any ditch that contributes perennial,
                intermittent, or ephemeral flow to other ``waters of the United
                States.''
                 In response to these diverse comments, the final rule does not
                include the separate category of ``ditches'' under paragraph (a)(3) as
                proposed and instead incorporates the elements of the proposal into the
                ``tributary'' category, with some additional clarifying edits. Ditches
                that are paragraph (a)(1) waters do not need to be identified in
                another jurisdictional category, so that aspect of the proposal has
                been eliminated as unnecessary and redundant. Ditches that are
                constructed in or that relocate a tributary are included in the final
                rule as tributaries, as long as the ditch satisfies the flow conditions
                of the ``tributary'' definition. The same is true for ditches that are
                constructed in adjacent wetlands.
                 The agencies did not retain the term ``alter'' from the proposed
                rule given the potential confusion associated with the use of that
                term. As some commenters noted, most, if not all, ditches may have some
                effect on and therefore may ``alter'' a tributary or some portion of
                the tributary system. As described throughout this notice, the CWA does
                not authorize the agencies to regulate all waters, nor does it
                authorize the agencies to regulate all ditches that exist across the
                landscape to assist in water management activities. The agencies
                conclude that ditches that are ``constructed in'' or that ``relocate''
                a tributary, and that satisfy the flow conditions of the ``tributary''
                definition, are appropriately within the authority granted to the
                agencies under the CWA, consistent with the legal principles outlined
                in Section II.E. The regulation
                [[Page 22296]]
                and management of all other ditches is appropriately left to States and
                Tribes as part of their primary authority over land and water resources
                within their border. See 33 U.S.C. 1251(b), 1370.
                 The agencies consider it to be clearer to include in the definition
                of ``tributary'' that the alteration of a tributary does not modify its
                jurisdictional status as a tributary as long as it continues to meet
                the flow conditions of the definition, rather than to classify the
                alteration of a tributary as a ditch. This is also consistent with
                longstanding agency practice. The agencies have modified the exclusion
                for ditches in paragraph (b)(5) to reflect these changes. The agencies
                also recognize that in certain circumstances, ditches that are
                constructed in adjacent wetlands that lack sufficient flow to be
                considered tributaries under this final rule may develop wetland
                characteristics if not maintained. As discussed below, in limited
                circumstances, those wetlands may be treated as adjacent wetlands,
                subject to the permitting exemptions in 33 U.S.C. 1344(f). All other
                ditches are excluded under the final rule.
                 The agencies believe that this approach to ditches best addresses
                the comments received and provides clarity and regulatory certainty to
                determine when a ditch may be a jurisdictional water and when a ditch
                may be excluded, consistent with the agencies' authority under the CWA.
                Finally, as discussed in Section III.A.3, non-jurisdictional ditches
                under this final rule may be capable of conveying channelized surface
                water flow between upstream relatively permanent jurisdictional waters
                and downstream jurisdictional waters in a typical year. In this
                example, the ditch itself, however, would remain non-jurisdictional.
                2. Summary of Final Rule Rationale and Public Comment
                 During the 1970s, the Corps interpreted its authorities under the
                CWA as excluding drainage and irrigation ditches from the definition of
                ``waters of the United States.'' See, e.g., 40 FR 31320, 31321 (July
                25, 1975) (``Drainage and irrigation ditches have been excluded.'').
                The ditch exclusion was expressly stated in regulatory text in the
                Corps' 1977 regulations. 33 CFR 323.2(a)(3); 42 FR 37122, 37144 (July
                19, 1977) (``manmade nontidal drainage and irrigation ditches excavated
                on dry land are not considered waters of the United States under this
                definition''). As the Corps explained in 1977: ``nontidal drainage and
                irrigation ditches that feed into navigable waters will not be
                considered `waters of the United States' under this definition. To the
                extent that these activities cause water quality problems, they will be
                handled under other programs of the FWPCA, including Section 208 and
                402.'' 42 FR at 37127 (July 19, 1977). Similar statements in preambles
                to the proposed rules from the early 1980s confirmed this
                interpretation: ``man-made, non-tidal drainage and irrigation ditches
                excavated on dry land are not considered waters of the United States.''
                45 FR 62732, 62747 (September 19, 1980); see also 48 FR 21466, 21474
                (May 12, 1983) (``Waters of the United States do not include the
                following man-made waters: (1) Non-tidal drainage and irrigation
                ditches excavated on dry land, (2) Irrigated areas which would revert
                to upland if the irrigation ceased.'').
                 The general exclusion for non-tidal drainage and irrigation ditches
                excavated in dry land continued through 1986, although the Corps
                modified its earlier statements that year by noting in preamble text
                that ``we generally do not consider'' such features to be ``waters of
                the United States,'' and indicating that the agency would evaluate
                certain ditches on a case-by-case basis. 51 FR 41206, 41217 (November
                13, 1986).\49\ The EPA also included similar language in a Federal
                Register notice in 1988. 53 FR 20764 (June 6, 1988). The Corps further
                clarified the regulation of ditches in its nationwide permit regulation
                in March 2000, stating that ``non-tidal drainage ditches are waters of
                the United States if they extend the [ordinary high water mark] of an
                existing water of the United States.'' 65 FR 12818, 12823 (March 9,
                2000). In other words, if flow or flooding from a jurisdictional non-
                tidal river or stream inundated an upland ditch, the agencies would
                assert jurisdiction over that upland ditch because the ordinary high
                water mark of the river or stream extends into the ditch, and the
                agencies would then assert jurisdiction over the entire reach of that
                ditch.
                ---------------------------------------------------------------------------
                 \49\ The Corps also moved the ditch exclusion from rule text to
                preamble language in 1986 but stated that this was not a substantive
                change and that jurisdiction was not expanded. 51 FR 41206, 41216-17
                (November 13, 1986).
                ---------------------------------------------------------------------------
                 This final rule clarifies the regulatory status of ditches in a
                manner that is more consistent with the Corps' regulations following
                the 1972 and 1977 CWA amendments, with some modifications to provide a
                clear definition that also falls within the scope of the agencies'
                authority under the CWA. When Congress enacted the 1972 amendments, it
                specifically included ditches and related artificial features as
                ``point sources,'' declaring them to be ``discernible, confined, and
                discrete conveyances . . . from which pollutants are or may be
                discharged.'' Public Law 92-500, 86 Stat. 816, 887 (1972) codified at
                33 U.S.C. 1362(14). Congress envisioned protecting the quality of the
                navigable waters, defined as ``waters of the United States'' at that
                time, by regulating the discharge of pollutants from conveyances like
                pipes, ditches, channels, tunnels and similar features into waters of
                the United States. Id. at 1362(12) (defining ``discharge of pollutant''
                as ``any addition of any pollutant to navigable waters from any point
                source'').
                 The agencies evaluated the treatment of ditches in the CWA and its
                legislative history to discern whether Congress intended ditches to be
                point sources, navigable waters, or both. For example, Congress
                exempted the discharge of dredged or fill material into waters of the
                United States when that discharge occurs as a result of the
                construction or maintenance of irrigation ditches, the maintenance of
                drainage ditches, or minor drainage associated with normal farming
                activities. 33 U.S.C. 1344(f)(1)(A), (C) (exempting such activities
                from sections 301, 402, and 404 of the Act). One possible
                interpretation of these exemptions is that they function as an implicit
                acknowledgement that there may be some irrigation or drainage ditches
                that are waters of the United States, thus the need to exempt common
                agricultural and related practices in those waters from CWA section 404
                permitting. Another interpretation is that dredged or fill material or
                other pollutant discharges arising from such activities are not subject
                to federal permitting if those materials get washed down the ditch into
                a connected water of the United States.
                 For irrigation ditches, which typically are constructed in upland
                but frequently must connect to a water of the United States to either
                capture or return flow, Congress exempted both the construction and
                maintenance of such facilities. 33 U.S.C. 1344(f)(1)(C); see also 33
                U.S.C. 1362(14) (excluding agricultural stormwater discharges and
                irrigation return flows from the definition of ``point source'').\50\
                The
                [[Page 22297]]
                construction activities performed in upland areas are beyond the reach
                of the CWA, but the permitting exemption applies to the diversion
                structures, weirs, headgates, and other related facilities that connect
                the irrigation ditches to jurisdictional waters. See, e.g., Corps,
                Regulatory Guidance Letter No. 07-02, at 1-2 (July 4, 2007).
                ---------------------------------------------------------------------------
                 \50\ The agencies also note that Congress exempted the discharge
                of irrigation return flows into waters of the United States from the
                section 402 permit program. 33 U.S.C. 1342(l). This exemption
                potentially would not be needed if agricultural drainage ditches
                carrying irrigation return flow were themselves waters of the United
                States, as the entry point of the irrigation return flow into the
                drainage ditch might then lack the requisite point source
                discharging mechanism given the diffuse overland flow entry point
                from the field to ditch in most circumstances.
                ---------------------------------------------------------------------------
                 For drainage ditches, by contrast, the permitting exemption is
                limited to only maintenance of such ditches. 33 U.S.C. 1344(f)(1)(C).
                That is because a parallel exemption for construction would allow the
                drainage of wetlands subject to CWA jurisdiction without a permit.
                Congress' intent to prevent such a result is evident in the
                ``recapture'' provision of 33 U.S.C. 1344(f)(2). See, e.g., Sen. Rpt.
                95-370, 95th Cong. 1st Sess., at 76-77 (July 19, 1977) (noting that
                exempted ``activities should have no serious adverse impact on water
                quality if performed in a manner that will not impair the flow and
                circulation patterns and the chemical and biological characteristics of
                the affected waterbody'' and noting that the ``exemption for minor
                drainage does not apply to the drainage of swampland or other
                wetlands'').
                 In summary, Congress may have envisioned the interconnection
                between the irrigation and drainage ditches and down-gradient waters of
                the United States as creating the need for the section 404(f)
                permitting exemptions, not necessarily that those ditches themselves
                are waters of the United States. Or Congress could have envisioned that
                some drainage ditches constructed in jurisdictional wetlands become
                waters of the United States themselves and thus require section 404(f)
                permitting exemptions for maintenance work performed in them. The
                agencies have not been able to identify any legislative history that
                signals the clear intent of Congress on this complex topic, and
                commenters provided a diverse range of viewpoints that failed to
                provide a clarifying position. To resolve the ambiguity, the agencies
                are interpreting the statutory text in section 404(f) and its
                legislative history as an indication that Congress may have intended,
                in certain limited circumstances, that ditches constructed in
                jurisdictional wetlands could become jurisdictional waters themselves.
                The agencies believe that the final rule formulation adheres more
                closely to the language of the statute and the positions articulated by
                the plurality opinion in Rapanos. See, e.g., 547 U.S. at 735-36 and
                n.7.
                 Many commenters requested the agencies clarify that a water of the
                United States and point source are mutually exclusive. Some commenters
                expressed concern about features which may be considered point sources
                rather than waters of the United States under the proposed rule, and
                whether such features would require section 402 permits to convey
                pollutants downstream. Other commenters stated that permit requirements
                may need to be modified by sampling at the downstream end of the ditch
                to demonstrate that pollutants are being added to a water of the United
                States. The final rule does not make any changes to the agencies'
                interpretation of the definition of ``point source'' in CWA section
                502(14). The agencies believe that this final rule will help clarify
                whether a ditch is a water of the United States or a point source.
                Either it is a water of the United States that subjects a discharger to
                sections 402 and 404 permitting requirements for direct discharges into
                the ditch, or, if it is non-jurisdictional but conveys pollutants to
                downstream jurisdictional waters, it may be a point source that
                subjects a discharger into a ditch to section 402 permitting
                requirements. Both scenarios could also be subject to statutory
                exemptions that would obviate the need for a permit. In addition, if
                the ditch is a non-jurisdictional water that does not convey
                pollutants, it would not require a permit.
                 The agencies recognize that a change in jurisdiction resulting from
                this rule may change the scope of application of the CWA regulatory
                programs to a particular water, but the longstanding approach that the
                agencies have taken to implementing and enforcing those programs would
                remain the same. If a CWA section 402 permit is not currently required
                for a discharge to a water, it is unlikely that this final rule will
                create a requirement for a new CWA permit. If a section 402 permit is
                currently required for a discharge to a water that is no longer
                jurisdictional under this final rule, that permit may no longer be
                required; it may still be required if the non-jurisdictional feature
                conveys a discharge of pollutants from a point source to a water of the
                United States; or it may still be required but the conditions
                associated with the permit may need to be modified, subject to
                applicable anti-backsliding permit requirements.
                 This final rule includes the agencies' longstanding interpretation
                that ditches that satisfy any of the conditions of a paragraph (a)(1)
                water are waters of the United States as paragraph (a)(1) waters. This
                also includes tidal ditches and ditches that transport goods and
                services in interstate and foreign commerce, as those ditches--more
                commonly referred to as ``canals''--provide important commercial
                navigation services to the nation and operate more like natural waters
                traditionally understood as navigable. See, e.g., id. at 736 n.7
                (Scalia, J., plurality) (``a permanently flooded man-made ditch used
                for navigation is normally described, not as a `ditch,' but a `canal'
                ''). The Los Angeles River, for example, is a water of the United
                States (having been determined to be a traditional navigable water) and
                is not excluded under paragraph (b) even where it has been channelized
                or concreted. Other examples include the St. Lawrence Seaway, the
                Sturgeon Bay Ship Canal, and the Chesapeake and Delaware Canal.
                 Under the final rule, the agencies limit the term ``waters of the
                United States'' to apply to clearly defined ditches and related
                features that meet the flow conditions of the ``tributary'' definition
                and are not otherwise excluded. The agencies include ditches in the
                ``tributary'' category that were constructed in or relocated a
                tributary and that continue to meet the flow conditions of the
                ``tributary'' definition. The final rule retains the agencies'
                longstanding position that the alteration or relocation of a tributary
                does not modify the jurisdictional status of that water. Accordingly,
                ditches that relocate a tributary or are constructed in a tributary
                would be jurisdictional as tributaries. This provision is also
                consistent with the agencies' longstanding, historic position that non-
                tidal ditches excavated in upland (and historically described as ``dry
                land'') are not jurisdictional.
                 The agencies also include ditches in the ``tributary'' category
                that were constructed in a wetland that meets the definition of
                ``adjacent wetland,'' as long as the ditch also satisfies the flow
                conditions of the ``tributary'' definition. As discussed above, this
                approach aligns the rule with the CWA section 404(f) permitting
                exemption for the maintenance but not construction of drainage ditches,
                and the associated concern expressed during the legislative process for
                the 1977 CWA amendments related to draining swamps and wetlands. The
                provision is restricted to ditches that satisfy the flow conditions of
                the definition of ``tributary,'' which aligns the treatment of
                jurisdictional ditches with natural tributaries. See Section III.D for
                a broader discussion of the ``tributary'' category.
                 Ditches used to drain surface and shallow subsurface water from
                cropland are a quintessential example of the interconnected
                relationship between land and water resource management, as
                [[Page 22298]]
                is the case for managing water resources in the Western United States,
                conveying irrigation water to and from fields, and managing surface
                water runoff from lands and roads following precipitation events--all
                activities that rely on ditches. See, e.g., FERC v. Mississippi, 456
                U.S. 742, 767 n.30 (1982) (characterizing ``regulation of land use [as]
                perhaps the quintessential state activity''). The majority of these
                ditches will not be jurisdictional under the final rule. This final
                rule therefore effectuates the clear policy directive from Congress to
                preserve and protect the primary authority of States over land and
                water resources within their borders. See 33 U.S.C. 1251(b), 1370.
                 Commenters had differing views on the jurisdictional status of
                ditches. Many commenters supported the agencies' proposed approach to
                exclude many types of ditches, in particular those ditches constructed
                in upland which do not relocate a tributary. Some commenters stated
                that ditches should be jurisdictional even if constructed in upland if
                they have perennial flow. Some commenters recommended the agencies use
                the function of the ditch as the basis for an exclusion, such as all
                agricultural ditches, regardless of flow. The agencies disagree with
                the inclusion of upland ditches as jurisdictional waters aside from
                ditches that relocate a tributary or that meet the conditions of
                paragraph (a)(1). Such ditches are not part of the naturally occurring
                tributary system and are not something the agencies consider to be
                within their authority to regulate under the CWA. Upland ditches (other
                than those ditches that relocate a tributary or that meet the
                conditions of paragraph (a)(1)) do not fall under the ordinary meaning
                of the term ``waters'' within the scope of the CWA. In general, upland
                ditches were not jurisdictional for decades under the agencies'
                previous definitions of ``waters of the United States,'' and they are
                not jurisdictional under this final rule (with the exceptions noted
                above). The agencies considered identifying and excluding ditches based
                on the function or purpose of the ditch but concluded that such an
                approach could result in the regulation of ditches with ephemeral flow
                and the exclusion of ditches which are essentially relocated
                tributaries. Both outcomes would be contrary to the agencies'
                interpretation of the scope of CWA jurisdiction described throughout
                this notice.
                 The agencies recognize that there have been questions over time
                about the jurisdictional status of ditches that are not maintained.
                Under this final rule, a ditch constructed in an adjacent wetland that
                contributes less than perennial or intermittent flow to a paragraph
                (a)(1) water in a typical year and that, due to lack of maintenance,
                gains wetland characteristics may be viewed as an adjacent wetland if
                it meets the definition of both ``wetlands'' under paragraph (c)(16)
                and ``adjacent wetlands'' under paragraph (c)(1). For example, a ditch
                constructed in an adjacent wetland that abuts a tributary may have
                portions that could be considered an adjacent wetland if the portions
                meet the definition of ``wetland.'' Only the portion or portions of the
                ditch that meets the definition of ``adjacent wetland'' are
                jurisdictional under this final rule. Other ditches not constructed in
                adjacent wetlands, or not otherwise covered by paragraph (a)(1) or (2),
                are excluded from jurisdiction under paragraph (b)(5). Such an approach
                aligns the treatment of ditches as tributaries and adjacent wetlands in
                this final rule with the section 404(f) permitting exemption for the
                maintenance but not construction of drainage ditches, and the
                associated concern expressed during the legislative process for the
                1977 amendments related to draining swamps and wetlands.
                 The agencies also note that the maintenance of certain
                jurisdictional ditches may occur without permitting under the section
                404(f) exemptions of the CWA. Congress expressly excluded the
                construction and maintenance of irrigation ditches and the maintenance
                of drainage ditches (such as farm or roadside drainage ditches, many of
                which are also excluded from jurisdiction under this rule) from the
                permitting requirements of sections 301, 402, and 404. Discharges of
                dredged or fill material associated with those exempt activities into a
                ditch constructed in an adjacent wetland are therefore exempt from CWA
                permitting, even if those materials are transported down the ditch to
                other jurisdictional waters. The agencies note that section 404(f) has
                a recapture provision that is designed to override the permitting
                exemptions in section 404(f) if the otherwise exempt activity alters
                the previous use of a jurisdictional water through impairment of the
                circulation or flow of such waters or a reduction in the reach of such
                waters. 33 U.S.C. 1344(f)(2). The agencies are aware that in some
                circumstances, questions about the applicability of this recapture
                provision to ditches that develop wetland characteristics have created
                confusion. Some question whether the development of wetland
                characteristics in a ditch establishes a new use for the water feature
                such that the recapture provision overrides the ditch maintenance
                exemption. This interpretation would eliminate the maintenance
                exemption from performing the very purpose Congress intended--allowing
                the dredging of the bottom of the ditch to eliminate obstructions to
                flow, including vegetation, without the need for a permit.
                 Many commenters noted that under the proposed rule, ditches must
                meet the definition of ``tributary'' to be jurisdictional, but because
                a ``ditch'' was defined as an artificial channel and a tributary was
                ``naturally occurring,'' a ditch could never meet the definition of
                ``tributary.'' The phrase ``naturally occurring'' does not exclude
                modified natural tributaries. The final rule clarifies that the
                ``alteration'' or ``relocation'' of a tributary does not modify its
                jurisdictional status as long as it originally occurred naturally and
                continues to satisfy the flow conditions of the definition. In
                addition, the agencies have clarified in the final rule that the
                definition of ``tributary'' includes ditches that are constructed in or
                relocate tributaries so long as the ditch satisfies the flow conditions
                of the definition. A ``naturally occurring'' tributary may be altered
                in such a manner that it no longer appears ``natural'' and instead has
                been constructed to become a channel that conveys water. One such
                example is the Los Angeles River. Such a feature may satisfy the
                definition of ``ditch'' in this rule, but it also satisfies the
                definition of ``tributary,'' which overrides the general exclusion for
                ditches in paragraph (b)(5) as clarified in that exclusion. A ditch
                that straightens a tributary is considered to be ``constructed in'' a
                tributary, and the ditch would be jurisdictional as a tributary so long
                as it continues to meet the flow conditions of the ``tributary''
                definition.
                 The proposed rule required ditches to satisfy the ``conditions'' of
                the ``tributary'' definition to be jurisdictional as tributaries;
                however, the agencies have clarified in the final rule that the ditches
                must satisfy the flow conditions of the ``tributary'' definition to be
                jurisdictional as a tributary. This requirement allows for such ditches
                to be artificial (as in not ``naturally occurring'') and still be
                considered tributaries. The agencies' longstanding interpretation of
                the CWA is that tributaries that are altered or relocated tributaries
                are jurisdictional, and the agencies are not changing this
                interpretation. If a tributary is channelized, its bed and/or banks are
                [[Page 22299]]
                altered in some way, it is re-routed and entirely relocated, or its
                flow is modified through water diversions or through other means, then
                it remains jurisdictional under the final rule as long as it continues
                to satisfy the flow conditions in the definition of ``tributary.''
                 Finally, the agencies note that starting in the early 2000s,
                certain ditches (such as roadside and agricultural ditches) have been
                regarded by the Corps as jurisdictional if water from another
                jurisdictional water, such as a perennial river, overflows into a ditch
                and extends the ordinary high water mark of the contributing water into
                the ditch. The Corps has then asserted jurisdiction over the entire
                ``reach'' of the ditch regardless of the location of the ordinary high
                water mark in that portion of the ditch. Under this final rule, the
                agencies will continue the existing practice of regulating portions of
                otherwise non-jurisdictional ditches as waters of the United States
                based on the ordinary high water mark of the contributing water, but
                only up to the location of the ordinary high water mark, as mandated by
                existing Corps regulations. The agencies will not, however, assert
                jurisdiction over the entire ``reach'' of the ditch regardless of the
                location of the ordinary high water mark in that portion of the ditch.
                Those regulations establish the limits of jurisdiction of non-tidal
                waters of the United States as extending to the ordinary high water
                mark and not beyond. See 33 CFR 328.4(c). The agencies note that
                continuing the practice of regulating portions of otherwise non-
                jurisdictional ditches based on the ordinary high water mark of
                contributing down-gradient waters will maintain better alignment with
                the rule's treatment of ditches subject to the ebb and flow of the tide
                as jurisdictional up to the tidal influence. It also provides some
                jurisdictional commonality with the treatment of certain lakes, ponds,
                and impoundments and adjacent wetlands as jurisdictional based on
                inundation by flooding from other jurisdictional waters.
                3. How will the agencies implement the final rule?
                 The agencies have determined that in order to be jurisdictional
                under this final rule, a ditch or other similar artificial feature
                would first need to meet the definition of ``ditch'' (i.e., a
                constructed or excavated channel used to convey water). Once a feature
                has been determined to meet the definition of ``ditch,'' a ditch would
                be considered a tributary where the ditch relocates a tributary, is
                constructed in a tributary, or is constructed in an adjacent wetland as
                long as the ditch satisfies the flow conditions of the ``tributary''
                definition. The phrase ``constructed in an adjacent wetland'' refers to
                ditches originating in or constructed entirely within an adjacent
                wetland. The phrase also includes ditches that are constructed through
                adjacent wetlands, but jurisdiction over those ditches only includes
                those portions in adjacent wetlands and downstream to other
                jurisdictional waters, as long as those portions satisfy the flow
                conditions of paragraph (c)(12). Jurisdiction does not extend to upland
                portions of the ditch prior to entry into an adjacent wetland.
                Consistent with the exclusion in paragraph (b)(5), a ditch or portions
                thereof may also be considered an adjacent wetland where it was
                constructed in an adjacent wetland and the portion in that wetland
                meets the conditions of paragraph (c)(1).
                 If ditches were tributaries prior to their construction and
                continue to meet the flow conditions of the ``tributary'' definition
                after construction, they are jurisdictional as tributaries under the
                final rule. The burden of proof lies with the agencies to demonstrate
                that a ditch relocated a tributary or was constructed in a tributary or
                an adjacent wetland. For example, if the agencies are not sure whether
                a ditch was constructed in a tributary given the physical appearance
                and functionality of the current ditch, the agencies will review the
                available evidence to attempt to discern when the ditch was constructed
                and the nature of the landscape before and after construction. If the
                evidence does not demonstrate that the ditch was located in a natural
                waterway, the ditch will be non-jurisdictional under this rule. If the
                evidence suggests that the ditch may have been constructed in a natural
                waterway, the agencies will review the available evidence to attempt to
                discern whether that natural waterway would qualify as a tributary
                under this final rule. Absent such evidence, the agencies will conclude
                that the ditch is non-jurisdictional. The same methods above for
                ditches constructed in a tributary apply when determining the
                jurisdictional status of a ditch constructed in an adjacent wetland.
                Note that under this final rule, a ditch cannot render an otherwise
                isolated wetland an ``adjacent wetland'' and thus jurisdictional on
                that basis, unless the ditch itself is a tributary. See Section III.G
                for further discussion regarding the jurisdictional status of wetlands
                under this final rule.
                 Many commenters noted that historic conditions at the time of ditch
                construction could be difficult to identify, and some commenters
                requested more specific guidance and standards of evidence which would
                be used by the agencies. Along with field data and current information
                on the subject water, historic tools and resources may be used to
                determine the presence of a tributary or adjacent wetland at the time
                of ditch construction, and several sources of information may be
                required to make such determination. Information sources may include
                historic and current topographic maps, historic and recent aerial
                photographs, local and state records and surface water management
                plans, agricultural records, street maintenance data, precipitation
                records, historic permitting and jurisdictional determination records,
                certain hydrogeomorphological or soil indicators, wetlands and
                conservation programs and plans, and functional assessments and
                monitoring efforts. For example, when a USGS topographic map displays a
                tributary located upstream and downstream of a ditch, this may indicate
                that the ditch was constructed in or relocated a tributary. As another
                example, an NRCS soil survey displaying the presence of specific soil
                series which are linear in nature and generally parallel to a potential
                ditch may be indicative of alluvial deposits formed by a tributary in
                which the ditch was constructed.
                 In addition, high-resolution aerial photographs may be used to
                identify whether there are or were characteristics of a tributary
                upstream or downstream of a ditch, indicating that a ditch may have
                been constructed in or relocated a tributary. In some cases, stream
                channel morphology is visible on the aerial photograph along with
                visible persistent water (e.g., multiple dates of aerial photography
                showing visible water) providing evidence of the flow classification
                necessary to identify a tributary under this rule at the time of ditch
                construction. However, characteristics of tributaries may not be
                visible in aerial photographs taken in areas with high shrub or tree
                cover, in which case aerial photographs or satellite imagery taken
                during ``leaf off'' may provide the most beneficial information. The
                burden of proof is on the agencies to determine the historic status of
                the ditch construction, and if evidence does not show that the ditch
                relocated a tributary, was constructed in a tributary, or was
                constructed in an adjacent wetland, then a determination would be made
                that the ditch is not jurisdictional under this final rule.
                [[Page 22300]]
                F. Lakes and Ponds, and Impoundments of Jurisdictional Waters
                1. What are the agencies finalizing?
                 The final rule includes a category of ``waters of the United
                States'' that combines lakes, ponds, and impoundments of jurisdictional
                waters into a single category. A lake, pond, or impoundment of a
                jurisdictional water meets the definition of ``waters of the United
                States'' if it (1) satisfies any of the conditions in paragraph (a)(1),
                i.e., it is a traditional navigable water like Lake Michigan or Lake
                Mead; (2) contributes surface water flow to the territorial seas or a
                traditional navigable water in a typical year either directly or
                through one or more jurisdictional waters; or (3) is inundated by
                flooding from a paragraph (a)(1) through (3) water in a typical year. A
                lake, pond, or impoundment of jurisdictional waters does not lose its
                jurisdictional status if it contributes surface water flow to a
                downstream jurisdictional water in a typical year through a channelized
                non-jurisdictional surface water feature, through a culvert, dike,
                spillway, or similar artificial feature, or through a debris pile,
                boulder field, or similar natural feature.
                 The agencies had proposed to include two separate categories for
                lakes, ponds, and impoundments of jurisdictional waters, one for
                jurisdictional lakes and ponds and another for jurisdictional
                impoundments. The proposal followed the historic treatment of
                jurisdictional impoundments in treating them separately as ``waters of
                the United States.'' For lakes and ponds, the agencies proposed
                including them as a separate waterbody-specific category for the first
                time, more clearly tethering jurisdiction over those features to the
                text of the statute and applicable Supreme Court guidance.
                 The agencies received a wide range of public comments on the
                proposed approach. Many commenters expressed support for including
                lakes and ponds as a separate category, while others also supported
                retaining separate treatment for impoundments of jurisdictional waters.
                Other commenters suggested that because lakes, ponds, and impoundments
                of jurisdictional waters are functionally similar they should be
                treated as a combined category. Some commenters stated that the
                proposal excluded too many lakes and ponds and said that the CWA should
                apply to such features regardless of their hydrologic surface
                connection to traditional navigable waters. Others argued that the
                proposal asserted jurisdiction over too many lakes and ponds. Some
                commenters stated that the agencies should adopt their longstanding
                treatment of jurisdictional impoundments, retaining jurisdiction over
                them even if they are completely disconnected from the tributary
                system. Others stated that the agencies should regulate impoundments of
                jurisdictional waters only if they continue to contribute flow to other
                jurisdictional waters, arguing for different flow regimes (i.e.,
                perennial only, perennial and intermittent, any hydrologic connection).
                The agencies have considered the full range of comments and have
                finalized a rule that balances these diverse viewpoints, as discussed
                below, while streamlining and improving the clarity and applicability
                of the rule and remaining faithful to the agencies' statutory
                authorities as discussed in Section II.B.
                2. Summary of Final Rule Rationale and Public Comment
                 Historically, the Corps' regulations specifically defined
                ``lakes,'' ``ponds,'' and ``impoundments.'' In 1975, for example, the
                Corps published an interim final regulation, 40 FR 31320 (July 25,
                1975), that administratively defined ``lakes'' as ``natural bodies of
                water greater than five acres in surface area and all bodies of
                standing water created by the impounding of [waters of the United
                States]. Stock watering ponds and settling basins that are not created
                by such impoundments are not included.'' 40 FR 31325. In response to
                the 1975 regulation, the Corps received a number of comments and
                criticisms regarding the definition of ``lake.'' Some stated that the
                size limitation was too small, while others stated that it was too
                large. Others questioned the legality of imposing any size limitation
                on natural lakes, arguing that a lake fewer than five acres in size is
                as much a ``water of the United States'' as one that is more than five
                acres in size. In response, the Corps established two new definitions
                in 1977, one for ``natural lake'' and one for ``impoundment.'' 42 FR
                37129-30 (July 19, 1977). The Corps believed the two definitions would
                help alleviate confusion over the broad definition of ``lake'' provided
                in 1975. In the 1977 regulation, ``natural lake'' was defined as ``a
                natural depression fed by one or more streams and from which a stream
                may flow, that occurs due to the widening or natural blockage of river
                or stream, or that occurs in an isolated natural depression that is not
                part of a surface river or stream.'' 42 FR 37144. The Corps believed
                that definition reflected the three types of situations in which a
                natural lake may exist. The 1977 regulation defined ``impoundment'' as
                a ``standing body of open water created by artificially blocking or
                restricting the flow of a river, stream, or tidal area. As used in this
                regulation, the term does not include artificial lakes or ponds created
                by excavating and/or diking dry land to collect and retain water for
                such purposes as stock watering, irrigation, settling basins, cooling,
                or rice growing.'' 42 FR 37144. No size limitation was placed on the
                1977 definitions, and instead, the size limitations were used as a
                distinguishing element of the CWA section 404 nationwide permit
                program.
                 In 1982, the Corps again published an interim final rule which
                combined ``natural lake'' and ``impoundment'' into one term, ``lake.''
                47 FR 31794-95 (July 22, 1982). Commenters stated that impoundments
                should not be given the same status in the review process as natural
                lakes; however, the Corps believed that the evaluation of the public
                interest should be based on what the impacts are, and not on whether
                the area in question is natural or manmade. In the 1982 regulations,
                the Corps defined ``lake'' as
                a standing body of open water that occurs in a natural depression
                fed by one or more streams from which a stream may flow, that occurs
                due to the widening or natural blockage or cutoff of a river or
                stream, or that occurs in an isolated natural depression that is not
                a part of a surface river or stream. The term also includes a
                standing body of open water created by artificially blocking or
                restricting the flow of a river, stream, or tidal area. As used in
                this regulation, the term does not include artificial lakes or ponds
                created by excavating and/or diking dry land to collect and retain
                water for such purposes as stock watering, irrigation, settling
                basins, cooling, or rice growing.
                47 FR 31811. This same definition was retained when the Corps issued
                its consolidated set of regulations in 1986 (51 FR 41206, November 13,
                1986); however, the term ``lake'' was only retained in the part of the
                regulations related to ``Permits for Discharges of Dredged or Fill
                Material into Waters of the United States'' (33 CFR 323) and was not
                included in the new part specifically related to the definition of
                ``waters of the United States'' (33 CFR 328). The definition of
                ``lake'' remains in the Corps' current regulation at 33 CFR 323.2(b),
                and includes, ``a standing body of open water created by artificially
                blocking or restricting the flow of a river, stream, or tidal area''
                but excludes, ``artificial lakes or ponds created by excavating and/or
                diking dry land to collect and retain water for such purposes as stock
                watering, irrigation, settling basins, cooling, or rice growing.''
                [[Page 22301]]
                 Until this final rule, the definition of ``waters of the United
                States'' has not included a separate category for lakes and ponds. To
                date, the agencies viewed non-isolated ``lakes and ponds'' as
                traditional navigable waters or as part of the tributary system where
                they met the tributary standard. For example, if a tributary enters a
                standing body of open water in a natural depression, such as a lake,
                which then outlets into a downstream tributary, the lake was considered
                part of the tributary system and the limits of jurisdiction were
                defined by the ordinary high water mark unless adjacent wetlands were
                present. Starting in the 1982 regulation, impoundments of waters
                otherwise defined as ``waters of the United States'' were included as a
                separate category of ``waters of the United States.'' See 40 CFR
                323.2(a)(4) (1983); 47 FR 31810 (July 22, 1982). In implementing its
                regulations, the Corps deemed impoundments ``waters of the United
                States'' when they were created from a water of the United States,
                still met another category of ``waters of the United States'' after
                creation, or were isolated with a nexus to interstate or foreign
                commerce.\51\
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                 \51\ See the U.S. Army Corps of Engineers Jurisdictional
                Determination Form Instructional Guidebook p. 58 at: https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2310.
                ---------------------------------------------------------------------------
                 In this rulemaking, the agencies proposed to maintain the
                ``impoundments'' category of ``waters of the United States'' as it
                existed in the 1980s regulation and proposed to create a new category
                for certain lakes and ponds. The agencies requested comment as to
                whether a separate category was needed for impoundments of
                jurisdictional waters or whether those features could be captured in
                other categories of ``waters of the United States,'' such as the
                proposed ``lakes and ponds'' category. The agencies received comments
                in support of maintaining a separate category for impoundments, which
                stated that doing so would provide clarity because it is consistent
                with the agencies' longstanding practice. Commenters supporting a
                separate category for impoundments also stated that impoundments are
                fundamentally different from lakes and ponds and therefore should be
                regulated differently. Other commenters supported combining the two
                categories and stated that lakes, ponds, and impoundments function
                similarly on the landscape and therefore should be regulated
                consistently. These commenters also stated that the agencies do not
                have legal authority to regulate impounded features that do not
                otherwise satisfy the jurisdictional requirements of the CWA. Other
                commenters generally found the term ``impoundment'' to be unclear and
                requested that the agencies include a definition of the term in the
                final rule. The agencies also requested comment on whether existing
                jurisdictional impoundments could become non-jurisdictional if they
                were no longer regulated as a separate category of ``waters of the
                United States.'' In response, some commenters raised a concern that, if
                impoundments are combined into a single category with lakes and ponds,
                adjacent wetlands that are impounded could lose their jurisdictional
                status.
                 The agencies received comments stating that lakes and ponds should
                not constitute a separate category of jurisdictional waters because
                these features do not have a universally-accepted definition. Some
                commenters stated that the category of lakes and ponds may be redundant
                with other categories of waters, such as impoundments, and that the
                extent of wetland vegetation within a shallow pond can change over
                time, making it difficult to distinguish between wetland and pond
                boundaries in some cases. Other commenters agreed that lakes and ponds
                should comprise a separate category of jurisdictional waters to
                distinguish them from other features such as tributaries and
                impoundments. Commenters noted that a separate category could increase
                regulatory certainty, as jurisdictional requirements may be different
                for lakes and ponds as compared to other categories of waters.
                 The agencies have considered these competing public comments and
                for the reasons provided below are finalizing the rule with a single
                category for lakes, ponds, and impoundments of jurisdictional waters.
                The agencies agree with the commenters that stated lakes, ponds, and
                impoundments function similarly on the landscape. The final rule is
                consistent with the Corps' existing definition of ``lakes'' that
                includes impoundments, although its ``lakes'' definition is not for
                purposes of defining ``waters of the United States.'' See 33 CFR
                323.2(b). Like lakes and ponds, many impoundments are lentic systems
                (i.e., still waters) as opposed to tributaries, which are typically
                lotic systems (i.e., flowing waters). In many areas of the country,
                lakes and ponds exist only because rivers and other flowing features or
                wetlands have been impounded. Impounded features often provide similar
                commercial opportunities, water quality benefits, and wildlife habitat
                as compared with natural features. Similarly, both naturally occurring
                (but modified) and impounded waters and wetlands may have structures,
                such as culverts, weirs, or pumps, that are designed to manage the
                movement of water upstream and downstream of the structure. The
                agencies conclude that because lakes, ponds, and impoundments of
                jurisdictional waters generally function similarly across the
                landscape, they should be regulated consistently.
                 In the final rule, certain lakes, ponds, and impoundments of
                jurisdictional waters are waters of the United States because these
                features are waters within the ordinary meaning of the term. As
                discussed in Section II.E, the plurality opinion in Rapanos stated that
                the term ``the waters'' is most commonly understood to refer to ``
                `streams and bodies forming geographical features such as oceans,
                rivers, [and] lakes,' or `the flowing or moving masses, as of waves or
                floods, making up such streams or bodies.' '' 547 U.S. at 732 (quoting
                Webster's New International Dictionary 2882 (2d ed. 1954) (emphasis
                added). The plurality also noted that its reference to ``relatively
                permanent'' waters did ``not necessarily exclude streams, rivers, or
                lakes that might dry up in extraordinary circumstances, such as
                drought.'' Id. at 732 n.5 (emphasis added).
                 Under the final rule, lakes, ponds, and impoundments that meet the
                conditions to be a traditional navigable water are waters of the United
                States under paragraph (a)(1) of this final rule. These waters are
                discussed in more detail in Section III.B. It would be redundant to
                include additional regulatory text in the lakes, ponds, and
                impoundments category that declares such water features to be
                jurisdictional if they satisfy the paragraph (a)(1) standard, as the
                agencies had proposed for lakes and ponds. For clarity and simplicity,
                the agencies are not including that cross reference in the final rule.
                 The final rule focuses in large part on the lake's, pond's, or
                impoundment's surface water connection to traditional navigable waters
                or the territorial seas so as to remain consistent with the overall
                structure and function of the CWA. See, e.g., SWANCC, 531 U.S. at 168
                n.3. This final rule presents a unifying legal theory for federal
                jurisdiction over waters and wetlands adjacent thereto that maintain a
                sufficient surface water connection to traditional navigable waters or
                the territorial seas and is supported by the legal precedent and
                principles articulated in this notice. As discussed in Section II, the
                agencies' authority to regulate ``the waters of the United
                [[Page 22302]]
                States'' is grounded in Congress' commerce power over navigation. Given
                the broad purposes of the CWA, the agencies can choose to regulate
                beyond waters more traditionally understood as navigable but must
                provide a reasonable basis for doing so. Lakes, ponds, and impoundments
                of jurisdictional waters that contribute surface water flow to
                traditional navigable waters or the territorial seas in a typical year
                fall within the statutory authorities delegated to the agencies by
                Congress. Federally regulating these features effectuates the
                objective, goals, and policies of the CWA. By contrast, the agencies
                conclude that when lakes, ponds, and impoundments of jurisdictional
                waters do not contribute surface water flow to a traditional navigable
                water or the territorial seas in a typical year, such lakes, ponds, and
                impoundments have an insufficient connection to jurisdictional waters
                to warrant federal jurisdiction, unless they are inundated by flooding
                from a paragraph (a)(1) through (3) water in a typical year. Regulating
                these features would push the outer limits of the agencies' delegated
                authorities and infringe on the powers of States to regulate their own
                land and water resources and therefore are not jurisdictional under
                this final rule. Through this combined category, the agencies are
                incorporating common principles from the Rapanos plurality and
                concurring opinions and respecting both the objective and the policy in
                CWA sections 101(a) and 101(b), respectively.
                 Some commenters stated that only perennial lakes, ponds, and
                impoundments conveying perennial flow to a downstream paragraph (a)(1)
                water should be considered ``waters of the United States.'' Other
                commenters maintained that lakes, ponds, and impoundments conveying
                ephemeral flow to a downstream paragraph (a)(1) water should also be
                considered jurisdictional. The agencies proposed that perennial or
                intermittent flow from a lake or pond to a paragraph (a)(1) water
                either directly or indirectly through another jurisdictional water
                could establish jurisdiction. Some commenters expressed concern that it
                would be too difficult to determine the flow regime of features
                connecting lakes and ponds to waters of the United States. The agencies
                disagree that it would be too difficult to determine flow regime to
                establish jurisdiction for lakes and ponds as proposed, as the agencies
                have been using flow classifications to make jurisdictional
                determinations since the 2008 Rapanos Guidance was issued. However,
                upon further consideration, the agencies conclude that the proposed
                rule's requirement for perennial or intermittent flow from a lake or
                pond to a downstream paragraph (a)(1) water would have severed
                jurisdiction for certain relatively permanent lakes and ponds that are
                regularly ``connected to'' traditional navigable waters via surface
                water flow. Such regular surface water flows allow such waters to
                connect and become indistinguishable when flowing (i.e., they look like
                one water). In the final rule, the agencies have eliminated the flow
                classification requirement and instead have clarified the types of
                features that can provide a sufficient surface water connection between
                the lake, pond, or impoundment of a jurisdictional water and a
                downstream jurisdictional water in a typical year to warrant federal
                jurisdiction consistent with the CWA. This will simplify implementation
                of this category.
                 As discussed in Section III.A.3, the agencies have determined that
                channelized non-jurisdictional ephemeral features are capable of
                providing a sufficient surface water connection and that they do not
                sever jurisdiction if they convey surface water flow between an
                upstream relatively permanent jurisdictional water and a downstream
                jurisdictional water in a typical year. In other words, an ephemeral
                feature between an upstream lake and a downstream jurisdictional water
                would not sever jurisdiction upstream if the ephemeral feature conveys
                channelized surface water flow sufficient to allow the upstream and
                downstream waters to mix in a typical year. By contrast, the agencies
                conclude that diffuse stormwater run-off and directional sheet flow
                over upland (non-jurisdictional features under paragraph (b)(4)) do not
                provide a sufficient surface water connection to downstream
                jurisdictional waters. Therefore, upstream lakes, ponds, and
                impoundments that are connected to downstream jurisdictional waters
                only by such flows are not jurisdictional. These types of connections
                do not satisfy the limiting principles articulated in SWANCC and the
                plurality and concurring opinions in Rapanos.
                 Lakes, ponds, and impoundments of jurisdictional waters often
                contribute surface water flow to other waters in a manner similar to a
                tributary. The agencies conclude that if these features contribute
                surface water flow to traditional navigable waters or the territorial
                seas in a typical year, they are jurisdictional for the same reasons
                that a tributary is jurisdictional. Lakes, ponds, and impoundments of
                jurisdictional waters that do not contribute surface water flow to a
                paragraph (a)(1) water in a typical year are not jurisdictional for the
                same reasons that streams are excluded if they do not contribute
                surface water flow to a paragraph (a)(1) water in a typical year. See
                Section III.D of this notice for additional discussion on tributaries.
                The agencies do not explicitly define ``lakes and ponds, and
                impoundments of jurisdictional waters'' in paragraph (c)(6) of the
                final rule to require those waters to be perennial and intermittent, as
                the agencies have required for tributaries in paragraph (c)(12).
                Nonetheless, ephemeral lakes, ponds, and impoundments are categorically
                excluded from jurisdiction under paragraph (b)(3) of the final rule.
                The key test for jurisdiction is that lakes, ponds, and impoundments of
                jurisdictional waters must contribute surface water flow to a paragraph
                (a)(1) water in a typical year. Waters that flow only in direct
                response to precipitation do not satisfy the permanence element of the
                phrase ``relatively permanent bodies of water'' and are not
                jurisdictional under this final rule.
                 The agencies conclude that the category of lakes, ponds, and
                impoundments of jurisdictional waters in this final rule reflects the
                limits of the agencies' authority that the plurality and concurring
                opinions recognized in Rapanos. By requiring a contribution of surface
                water flow from a lake, a pond, or an impoundment of jurisdictional
                waters to a paragraph (a)(1) water in a typical year, the agencies are
                establishing that a mere hydrologic connection cannot provide the basis
                for CWA jurisdiction; the connection must be a surface water connection
                that occurs in a typical year. Such connection to a paragraph (a)(1)
                water is sufficiently frequent to warrant federal jurisdiction. This
                requirement reflects the Rapanos plurality's description of a ``wate[r]
                of the United States'' as ``i.e., a relatively permanent body of water
                connected to traditional interstate navigable waters.'' Id. at 742
                (emphasis added). It is also informed by the Rapanos plurality's
                rejection of the overly broad hydrologic connection theory that the
                Federal government had advanced in that case. The plurality concluded
                that the phrase ``the waters of the United States'' ``cannot bear the
                expansive meaning that the Corps would give it,'' id. at 732, and
                rejected the notion that ``even the most insubstantial hydrologic
                connection may be held to constitute a `significant nexus.' '' Id. at
                728. Justice Kennedy
                [[Page 22303]]
                further established that ``mere hydrologic connection should not
                suffice in all cases; the connection may be too insubstantial for the
                hydrologic linkage to establish the required nexus with navigable
                waters as traditionally understood.'' Id. at 784-85.
                 An impoundment may lose its surface water connection to a
                downstream jurisdictional water due to any number of reasons, including
                consumptive use or evaporation or due to the structure that was
                constructed to impound the water. In the proposed rule, all
                impoundments of jurisdictional waters would be jurisdictional,
                regardless of any surface water connection to a downstream (a)(1)
                water. The agencies supported the proposed rule in part by citing the
                Supreme Court's decision in S.D. Warren Co. v. Maine Board of
                Environmental Protection, 547 U.S. 370 (2006), for the proposition that
                impounding a jurisdictional water does not change its status as a
                ``water of the United States.'' 84 FR 4154, 4172 (Feb. 14, 2019),
                citing S.D. Warren Co., 547 U.S. at 379 n.5. The agencies solicited
                comment on the category of ``impoundments'' in the proposed rule,
                including whether impoundments that release water downstream, but do so
                less than intermittently, should remain jurisdictional. Some commenters
                agreed that S.D. Warren Co. would authorize disconnected and isolated
                impounded waters to remain jurisdictional and supported the agencies'
                longstanding position that such impoundments of waters of the United
                States remain jurisdictional. Other commenters stated that impoundments
                that lack a surface connection to a downstream jurisdictional water
                should not be waters of the United States. The agencies conclude that
                an impounded water that lacks a sufficient surface water connection to
                a downstream paragraph (a)(1) water in a typical year is not a water of
                the United States. This interpretation of federal regulatory authority
                over impoundments is most consistent with the scope of authority
                granted by Congress and the legal principles articulated in Section
                II.E of this notice. On further review and consideration, the agencies
                observe that S.D. Warren Co. analyzes the definition of ``discharge''
                in CWA section 502(16) but does not grapple with or address the subject
                of this rulemaking--the definition of ``waters of the United States.''
                The cited footnote in that case merely states that exerting private
                control over water flow (an everyday occurrence in many parts of this
                country) does not ``denationalize'' otherwise national waters. S.D.
                Warren Co., 547 U.S. at 379 n.5 (``[W]e [cannot] agree that one can
                denationalize national waters by exerting private control over
                them.''). The case did not address what happens when a water of the
                United States is so altered as to significantly modify its connection
                to traditional navigable waters, nor did the cases cited in that
                opinion. For example, waters of the United States are regularly
                defederalized under the section 404 permitting program--in some
                instances by transforming portions of traditional navigable waters for
                harbor development, and jurisdictional wetlands or small tributaries to
                fast land for communities and energy development, and in other
                instances by cutting off or separating part of jurisdictional waters
                that nonetheless remain waters, as is the case with certain causeway
                construction or application of the waste treatment exclusion for
                natural resource development projects. Furthermore, the agencies are
                aware of no decision of the Supreme Court that has ruled that the
                indelibly navigable principle applies to all waters of the United
                States, although the principle does apply to certain traditional
                navigable waters or any decision that would prohibit the United States
                from consenting to defederalization of a water by a lawfully issued
                section 404 permit. In this final rule, the agencies have defined
                ``waters of the United States'' not to include a water--including an
                impoundment of a jurisdictional water--that lacks a sufficient surface
                water connection to a downstream traditional navigable water,
                consistent with the principles articulated in SWANCC. See SWANCC, 531
                U.S. at 168 n.3. Impoundments of traditional navigable waters that
                continue to meet the criteria in paragraph (a)(1) of this final rule
                would remain jurisdictional under the CWA. S.D. Warren is not to the
                contrary.
                 The agencies recognize that many lakes, ponds, and impoundments of
                jurisdictional waters may be connected to other jurisdictional waters
                by a variety of natural and artificial non-jurisdictional features. The
                agencies have specified under this final rule that lakes, ponds, and
                impoundments of jurisdictional waters do not lose their jurisdictional
                status if they contribute surface water flow to a downstream
                jurisdictional water in a typical year through a channelized non-
                jurisdictional surface water feature, through a culvert, dike,
                spillway, or similar artificial feature, or through a debris pile,
                boulder field, or similar natural feature. The agencies describe in
                Section III.A.3 of this notice that such non-jurisdictional features do
                not sever jurisdiction when surface water flow is conveyed in a typical
                year, and that such flow leads to mixing between an upstream relatively
                permanent jurisdictional water and a downstream jurisdictional water.
                Consistent with this discussion, a non-jurisdictional feature remains
                non-jurisdictional even if it provides a channelized surface water
                connection between jurisdictional waters in a typical year.
                 Lakes, ponds, and impoundments of jurisdictional waters that are
                inundated by flooding from a paragraph (a)(1) through (3) water in a
                typical year are also waters of the United States under this final
                rule. See Rapanos, 474 U.S. at 732 (Scalia, J., plurality) (recognizing
                that the term ``the waters'' within ``the waters of the United States''
                includes ``the flowing or moving masses, as of waves or floods, making
                up . . . streams or bodies'') (emphasis added) (internal quotations
                omitted); id. at 770 (Kennedy, J., concurring in the judgment) (``the
                term `waters' may mean `flood or inundation' events that are
                impermanent by definition'') (emphasis added) (internal citations
                omitted). During times of inundation by flooding from a paragraph
                (a)(1) through (3) water to a lake, pond, or impoundment of
                jurisdictional waters in a typical year, such a water is
                indistinguishable from the jurisdictional water from which the flooding
                originates.
                 Inundation sufficient to establish jurisdiction occurs only in one
                direction, from the paragraph (a)(1) through (3) water to the lake,
                pond or impoundment of jurisdictional waters, rendering the feature
                ``itself a part of those waters'' ``that are `waters of the United
                States' in their own right.'' Rapanos, 547 U.S. at 740, 742 (Scalia,
                J., plurality). The agencies received a comment that the inundation
                requirement should create jurisdiction if it occurs in either or both
                directions, rather than just from a jurisdictional water to a lake,
                pond or impoundment. For the reasons discussed above, the agencies have
                concluded that in order to be considered part of the tributary system,
                the surface water flow from a lake, pond, or impoundment of
                jurisdictional waters to a paragraph (a)(1) through (3) water needs to
                occur with sufficient frequency that the flow is channelized in a
                typical year. Non-channelized diffuse overland flow from an otherwise
                isolated waterbody lacks the indicia of permanence and sufficiency
                necessary to establish jurisdiction, as described in more detail in
                Section III.A.3. Mere hydrologic surface connection is not enough. Id.
                at 784 (Kennedy, J., concurring in the
                [[Page 22304]]
                judgment). Flooding in a typical year from a paragraph (a)(1) through
                (3) water to a lake, pond, or impoundment of jurisdictional waters
                (that is not otherwise jurisdictional under the tests described above)
                is sufficient to establish jurisdiction. That is because inundation by
                flooding in a typical year makes the lake, pond or impoundment of
                jurisdictional waters ``part of'' the jurisdictional water, as may
                occur, for example, when an oxbow lake is located in a former channel
                of a meandering river. The agencies note, however, that oxbow lakes are
                not categorically jurisdictional under the final rule; to be
                jurisdictional, they must satisfy one or more of the conditions of
                paragraph (c)(6).
                 Some commenters expressed concern that, as proposed, lakes and
                ponds may be considered jurisdictional due to a single flood event in a
                typical year and suggested incorporating a flood duration requirement
                so that brief, infrequent floods from a paragraph (a)(1) through (3)
                water would not cause a lake or pond to become jurisdictional. Under
                the final rule, inundation by flooding from a paragraph (a)(1) through
                (3) water to a lake, pond, or impoundment of jurisdictional waters can
                occur as a result of seasonal or permanent flooding, for example, so
                long as flood waters connect such waters to a paragraph (a)(1) through
                (3) water in a typical year and have as their source a paragraph (a)(1)
                through (3) water. The agencies are not including a minimum number of
                flood events or duration of flooding that must take place in the course
                of a typical year, due to the need to accommodate regional hydrological
                differences. However, a mere hydrologic connection between a non-
                navigable, isolated lake, pond, or impoundment and a jurisdictional
                water is insufficient to establish jurisdiction under this rule. For
                instance, a lake that may be connected to a water of the United States
                by flooding, on average, once every 100 years is not jurisdictional. To
                be jurisdictional, a lake, pond, or impoundment of jurisdictional
                waters that is otherwise physically separated from a water of the
                United States must be inundated by flooding from a paragraph (a)(1)
                through (3) water at least once during a typical year. Oxbow lakes, for
                example, may be jurisdictional under this category via inundation where
                they otherwise may not satisfy the flow contribution elements of
                paragraph (c)(6) of the final rule.
                 The agencies have determined that an ecological connection between
                physically separated lakes, ponds, and impoundments of jurisdictional
                waters and other paragraph (a)(1) through (3) waters is insufficient to
                assert jurisdiction over such waters. See Rapanos, 547 U.S. at 741-42
                (Scalia, J., plurality) (``SWANCC found such ecological consideration
                irrelevant to the question whether physically isolated waters come
                within the Corps' jurisdiction.''). Some commenters requested that the
                agencies eliminate a case-specific ``significant nexus'' analysis for
                lakes and ponds, while other commenters supported maintaining a
                ``significant nexus'' analysis and identifying jurisdictional lakes and
                ponds based on ecological connections to water features such as
                traditional navigable waters and the territorial seas. The agencies
                have concluded that the lakes, ponds, and impoundments of
                jurisdictional waters category should replace existing procedures that
                may depend on a case-specific ``significant nexus'' analysis of the
                relationship between a particular water feature and downstream
                traditional navigable waters. Lakes, ponds, and impoundments of
                jurisdictional waters constitute a category of ``waters of the United
                States'' that is more consistent and predictable for members of the
                public and regulatory agencies to implement than a case-specific
                ``significant nexus'' analysis.
                 The approach to lakes, ponds, and impoundments of jurisdictional
                waters in this final rule is also intended to avoid ``impairing or in
                any manner affecting any right or jurisdiction of the States with
                respect to waters (including boundary waters) of such States.'' 33
                U.S.C. 1370. For example, lakes, ponds, and impoundments of
                jurisdictional waters are not waters of the United States if they do
                not contribute surface water flow to a traditional navigable water in a
                typical year or are not inundated by flooding from a paragraph (a)(1)
                through (3) water in a typical year. Rather, they are water resources
                of the States (or Tribes), and therefore States have an inherent
                interest in managing such features pursuant to the powers reserved to
                the States under the Constitution (and Tribes have analogous interests
                as well). See., e.g., North Dakota, 127 F. Supp. 3d at 1059. States and
                Tribes may therefore address such features under their own laws to the
                extent they deem appropriate.
                 To address comments that combining the lakes and ponds category
                with impoundments could result in impounded adjacent wetlands losing
                jurisdiction, the agencies have made minor modifications to the final
                regulatory text from the proposal. Under the final rule, impoundments
                of wetlands are jurisdictional as ``impoundments of jurisdictional
                waters'' if the wetlands being impounded first meet the definition of
                ``adjacent wetlands'' and then meet the conditions of the lakes, ponds,
                and impoundments of jurisdictional waters category. For example, under
                the final rule, impounded adjacent wetlands are jurisdictional as
                ``impoundments of jurisdictional waters'' if they form a feature that
                meets the conditions of the lakes, ponds, and impoundments of
                jurisdictional waters category. That is, adjacent wetlands that are
                impounded frequently become ponds and may lose their jurisdictional
                status as adjacent wetlands because they no longer satisfy all three
                factors of the ``wetlands'' definition. The final rule would ensure
                that these waters remain jurisdictional if they satisfy the elements of
                paragraph (c)(6). If those impounded wetlands, however, continue to
                satisfy the definition of ``adjacent wetlands,'' they would remain
                jurisdictional as adjacent wetlands. In the uncommon circumstance where
                an impoundment completely severs the surface water connection between
                an adjacent wetland and a jurisdictional water in a typical year, such
                that the feature no longer satisfies the definition of ``adjacent
                wetlands,'' the wetland would no longer be jurisdictional under this
                final rule. Section III.G of this notice provides additional discussion
                on adjacent wetlands.
                 The agencies acknowledge that this final rule represents a change
                from the agencies' longstanding practice concerning impoundments of
                jurisdictional waters. Under the 2019 Rule, notwithstanding the
                principles of SWANCC, impoundments of jurisdictional waters would be
                jurisdictional under the separate impoundments category regardless of
                any surface water connection to a downstream jurisdictional water. The
                agencies now conclude that this prior interpretation is not supported
                by the text, structure, or legislative history of the CWA, Supreme
                Court precedent, or the foundational legal principles of this final
                rule. See Section II.E. Justice Kennedy's concurring opinion also
                indicates that completely isolated waters are too remote to be
                regulated under the Commerce Clause powers. See 547 U.S. at 779
                (Kennedy, J., concurring in the judgment) (``Nevertheless, the word
                `navigable' in the Act must be given some effect. Thus, in SWANCC the
                Court rejected the Corps' assertion of jurisdiction over isolated ponds
                and mudflats bearing no evident connection to navigable-in-fact
                waters.'' (internal citation omitted)). The
                [[Page 22305]]
                agencies conclude that this principle should be applied to all waters,
                whether they are impoundments or not. The final rule is also consistent
                with the agencies' longstanding practice that a jurisdictional water
                may be altered and made non-jurisdictional by obtaining a CWA section
                404 permit to place fill material in a wetland or other water, thereby
                converting that water to fast land.
                 Some commenters requested the agencies define the terms ``lake''
                and ``pond,'' but other commenters stated that there were deficiencies
                in the proposed alternatives for defining ``lakes'' and ``ponds'' such
                as the definitions based on size, depth, or the Cowardin classification
                system developed by the U.S. Fish and Wildlife Service. Although
                regional naming conventions may vary, the agencies conclude that the
                terms ``lake'' and ``pond'' are well-understood and that additional
                regulatory definitions beyond what is included in the final rule are
                not necessary. Rather than defining ``lakes'' and ``ponds'' based on
                their geomorphology or artificial or natural status, the agencies have
                instead defined surface water characteristics and conditions in
                paragraph (c)(6) for purposes of establishing jurisdiction over lakes
                and ponds (i.e., standing bodies of open water that contribute surface
                water flow to traditional navigable waters or are inundated by flooding
                from a paragraph (a)(1) through (3) water in a typical year). The same
                is true for the term ``impoundment,'' which some commenters suggested
                is unclear. The agencies intend the term ``impoundment,'' as it is used
                in this rule and as it is used in common parlance, to mean a standing
                body of open water that is formed by blocking or restricting the flow
                of a pre-existing river, stream, or tidal area or by blocking or
                restricting the water of a pre-existing wetland, lake, or pond. Compare
                Webster's II, New Riverside University Dictionary (1994) (defining
                ``impound'' to mean to ``confine in'' or to ``accumulate (water) in a
                reservoir''). This is generally consistent with the Corps' current
                definition in 33 CFR 323.2(b) and should provide sufficient guidance
                for the public to understand the regulation. An impoundment that holds
                back, blocks, or restricts the flow of a water of the United States is
                considered ``constructed in'' that water for purposes of this final
                rule, even if portions of the impounded water also cover areas that
                were originally upland or non-jurisdictional waters.
                3. How will the agencies implement the final rule?
                 Lakes and ponds are naturally formed through a variety of events,
                including glacial, tectonic, and volcanic activity. Natural lakes and
                ponds can also be subsequently modified to change surface elevation,
                depth, and size. In some parts of the country these modified lakes and
                ponds are referred to as impoundments, whether they impound or enlarge
                an existing water of the United States or modify a non-jurisdictional
                water; in other areas, these may retain lake or pond nomenclature.
                Lakes, ponds, and impoundments can be man-made features constructed for
                industrial and agricultural uses, power generation, domestic water
                supply, or for aesthetic or recreational purposes. Many lakes, ponds,
                and impoundments have at least one outflow in the form of a river,
                stream, or drain which maintain a feature's surface water level or
                stage by allowing excess water to discharge. Some lakes, ponds, and
                impoundments do not have an outflow and lose water solely by
                evaporation, underground seepage, or consumptive use. Individual lakes,
                ponds and impoundments range in size. Ponds are generally smaller in
                size than lakes, but regional naming conventions vary. Lakes are also
                generally deeper than ponds. Like lakes and ponds, impoundments can be
                large or small, deep or shallow. Some of these waters are
                jurisdictional under paragraph (a)(3) of the final rule, as discussed
                above, while others are non-jurisdictional, particularly many
                artificial lakes and ponds pursuant to paragraph (b), as discussed in
                Section III.H.
                 Lakes, ponds, and impoundments are familiar types of waters that
                can be easily identified by landowners; the agencies; local, State, and
                tribal governments; consultants; and others. The tools discussed in
                Section III.D of this notice to identify the presence of a potential
                tributary can also be helpful to establish the presence of a lake,
                pond, or impoundment. For example, indication of an enclosed body of
                water on a USGS topographic map or certain waterbody types in the NHD
                data may show that a lake, pond, or impoundment is present. USGS
                topographic maps often include different symbols to indicate perennial
                and intermittent lakes and ponds where such features are mapped. See
                ``Topographic Map Symbols,'' available at https://pubs.usgs.gov/gip/TopographicMapSymbols/topomapsymbols.pdf. Waterbodies such as perennial
                and intermittent lakes and ponds, and reservoirs are also represented
                in NHDWaterbody, where such features are mapped.\52\ The NHD portrays
                the spatial geometry and the attributes of the features. However, as
                the agencies recognize in Section IV, these tools were not designed to
                indicate the jurisdictional status of waters of the United States, and
                limitations associated with these maps and data sets may require field-
                verification for accuracy.
                ---------------------------------------------------------------------------
                 \52\ See ``Complete FCode list for NHD Hydrography Features,''
                available at https://nhd.usgs.gov/userGuide/Robohelpfiles/NHD_User_Guide/Feature_Catalog/Hydrography_Dataset/Complete_FCode_List.htm.
                ---------------------------------------------------------------------------
                 After identifying a lake, pond, or impoundment, the next step is to
                determine whether the lake, pond, or impoundment meets the conditions
                of a paragraph (a)(1) water under the final rule and would therefore be
                regulated under that category. Consistent with the agencies'
                longstanding regulation and practice, paragraph (a)(3) waters do not
                include impoundments of non-jurisdictional waters. If an impoundment
                does not meet the conditions of a paragraph (a)(1) water, then the
                agencies must establish whether the feature is an impoundment of a
                jurisdictional water. The agencies may use historical and current
                sources of information such as construction plans, permit records,
                aerial photography, maps, and remote sensing data, as well as
                topographic information or relevant field data from site visits, to
                determine whether an impoundment was created by impounding a
                jurisdictional water such as a tributary or adjacent wetland. In making
                a jurisdictional determination under this rule, the agencies would
                evaluate the open body of water or wetland.\53\
                ---------------------------------------------------------------------------
                 \53\ The agencies note that the construction of a physical
                structure that impounds a body of water (e.g., a dam, berm, or weir)
                may require a CWA section 404 permit (e.g., when a discharge of
                dredged or fill material into a jurisdictional water occurs during
                construction of the impounding structure), in addition to other
                authorizations which may be required, such as a RHA section 9 or
                section 10 permit.
                ---------------------------------------------------------------------------
                 If a lake, pond, or impoundment of a jurisdictional water does not
                meet the conditions of a paragraph (a)(1) water, then the agencies
                would determine whether the water directly or indirectly contributes
                surface water flow to a paragraph (a)(1) water in a typical year, or is
                inundated by flooding from a paragraph (a)(1) through (3) water in a
                typical year. The agencies could use similar sources of information
                indicating the existence of a lake, pond, or impoundment to determine
                whether the water feature contributes surface water flow to a paragraph
                (a)(1) water in
                [[Page 22306]]
                a typical year. Many commenters requested that the agencies identify
                specific sources of information that would be used to determine whether
                lakes, ponds, and impoundments contribute surface water flow to a water
                of the United States. A combination of the tools and other resources
                described in Section III.D.3 may be used to establish jurisdiction of a
                lake, pond, or impoundment. For instance, if utilizing the NHD,
                waterbodies that are classified as a lake/pond or a reservoir in the
                dataset may have NHDFlowline artificial paths represented as flowing
                through them to complete a stream network and as a surrogate for
                general water flow direction. Combining this information with site
                visits, climate data, and surrounding hydrology data can yield greater
                certainty as to the presence of a lake, pond, or impoundment, and as to
                whether the feature contributes surface water flow to a downstream
                paragraph (a)(1) water in typical year. These tools may also be helpful
                in indicating whether a lake, pond, or impoundment of a jurisdictional
                water is part of the tributary network of a paragraph (a)(1) water. For
                example, the presence of a ``blue line stream'' on USGS topographic or
                NHD maps which extends from the feature may indicate that the lake,
                pond, or impoundment contributes surface water flow, directly or
                indirectly through a paragraph (a)(2) through (4) water, to a paragraph
                (a)(1) water in a typical year, which may indicate that the feature is
                jurisdictional. Other complementary data sources that can be used in
                conjunction with maps to determine the potential jurisdictional status
                of a lake, pond, or impoundment of a jurisdictional water include gage
                data, bathymetry data, elevation data, spillway height, historic water
                flow records, flood predictions, statistical evidence, aerial
                photographs, remote sensing data, and hydrologic and non-hydrologic
                field observations.
                 A lake, pond, or impoundment of a jurisdictional water does not
                lose its jurisdictional status if it contributes surface water flow to
                a downstream jurisdictional water in a typical year through a
                channelized non-jurisdictional surface water feature; through a
                culvert, dike, spillway, or similar artificial feature; or through a
                debris pile, boulder field, or similar natural feature. Under the final
                rule, the agencies have determined that lakes, ponds, and impoundments
                of jurisdictional waters may be jurisdictional if they have a
                channelized surface water connection to a paragraph (a)(1) water in a
                typical year. To determine the existence of channelized non-
                jurisdictional surface water features (e.g., ephemeral streams or non-
                jurisdictional ditches), culverts, dikes, spillways, or similar
                artificial features, or debris piles, boulder field, or similar natural
                features, the agencies may use remote sensing data, aerial photography,
                and field observations. The agencies may also rely on elevation data,
                aerial photography, remote sensing data, hydrologic models, flow data,
                field indicators, operation records, and visual observations to
                determine whether flow likely occurs through these non-jurisdictional
                water features in a typical year.
                 Lakes, ponds, and impoundments of jurisdictional waters that are
                inundated by flooding from a paragraph (a)(1) through (3) water in a
                typical year are also waters of the United States under this rule.
                Commenters noted that field observations, sometimes based on multiple
                site visits, may be necessary to determine that a surface water
                connection exists for lakes and ponds as a result of flooding from a
                traditional navigable water, tributary, or other jurisdictional lake or
                pond, or jurisdictional impoundment. Many commenters also stated that
                establishing a surface water connection based on inundation from a
                paragraph (a)(1) through (3) water to a lake or pond in a typical year
                may be difficult to implement. The agencies disagree with this
                suggestion as they are frequently asked to complete jurisdictional
                determinations when surface water connections are not present. In these
                cases, the agencies have used a variety of data sources that do not
                depend on visual observations of inundation, including but not limited
                to flood records, precipitation data, elevation data, aerial
                photography, remote sensing data, and hydrologic models. The agencies
                will complement remote tools with hydrologic and non-hydrologic field
                observations when necessary to determine the presence of a
                jurisdictional lake, pond, or impoundment due to inundation by flooding
                from a paragraph (a)(1) through (3) water.
                 The agencies recognize that artificial features such as a dike or
                berm could prevent a lake or pond from releasing surface water
                downstream to a water of the United States in a typical year.
                Similarly, a dam could prevent an impounded water from releasing
                surface water downstream to a water of the United States in a typical
                year. Under the final rule, lakes, ponds, and impoundments of
                jurisdictional waters are jurisdictional if they meet the conditions of
                paragraph (c)(6), including contributing surface water flow to a
                downstream jurisdictional water in a typical year. Such contribution
                could occur through pumps, flood gates, reservoir releases, or other
                mechanisms. The agencies do not distinguish between natural and
                artificially-manipulated surface water flow that connects a lake, pond,
                or impoundment with another water of the United States in a typical
                year. Furthermore, if an artificial feature such as a dike or dam
                causes a channelized downstream perennial or intermittent feature to
                become ephemeral, that channelized ephemeral feature would be non-
                jurisdictional under paragraph (b)(3) but would not sever jurisdiction
                of upstream features as long as it conveys surface water flow in a
                typical year to a downstream paragraph (a)(1) water.
                 In Section III.A.1 of this notice, the agencies describe a variety
                of methods and data sources that could be used to determine whether
                conditions meet the definition of ``typical year.'' For instance, the
                agencies have developed and utilized a method for determining normal
                precipitation conditions. The agencies currently use professional
                judgment and a weight of evidence approach as they consider
                precipitation normalcy along with other available data sources. The
                agencies recognize the need to consider seasonality and timing of
                surface water connections in utilizing the data sources described above
                and determining whether lakes, ponds, and impoundments meet the
                conditions of paragraph (c)(6) in the final rule. For example, a lake,
                pond, or impoundment of a jurisdictional water may be inundated by
                flooding from a paragraph (a)(1) through (3) water only during
                seasonally wet conditions. If the agencies complete a jurisdictional
                determination during seasonally dry conditions and do not visually
                observe inundation, they may use the multiple tools described above,
                including remote- and field-based hydrologic and non-hydrologic
                indicators, to determine whether inundation from flooding would
                typically occur during seasonally wet conditions.
                 A few commenters discouraged the agencies from relying solely on
                one source of data and recommended that mapping sources should be
                paired with remote sensing and field verification data. As described
                above, the agencies encourage the use of multiple complementary data
                sources to establish the presence of lakes, ponds, and impoundments and
                to determine their jurisdictional status. For example, waterbody and
                flowline features in the NHD could be used to determine the
                [[Page 22307]]
                likelihood of an existing lake, pond, or impoundment that has a direct
                or indirect surface water connection to a paragraph (a)(1) water. A
                site visit could then confirm the existence of the lake, pond, or
                impoundment, and aerial photography and physical field indicators or
                local knowledge could establish the likelihood of recent inundation.
                Finally, the agencies could determine whether climatic conditions meet
                the definition of ``typical year'' using, for example, the method for
                determining normal precipitation conditions described in Section
                III.A.1 of this notice, combined with other relevant sources of
                information such as the Palmer Drought Severity Index. Many commenters
                noted that the availability of data records and tools may vary across
                the country. The agencies have determined that the information provided
                by the tools described herein and other available information will vary
                in availability and accuracy in different parts of the country, and
                will take that into account when utilizing their expert judgment in
                evaluating the information prior to determining the jurisdictional
                status of a lake, pond, or impoundment of a jurisdictional water.
                 Some commenters asked whether features could simultaneously be
                excluded from regulation as artificial lakes and ponds, but also meet
                the definition of jurisdictional impoundments. As discussed in Section
                III.H of this notice, paragraph (b)(8) of the final rule specifies that
                the artificial lakes and ponds exclusion does not apply to
                jurisdictional impoundments. An artificial lake or pond will be
                excluded even if it satisfies the definition in paragraph (c)(6), so
                long as it was constructed or excavated in upland or in non-
                jurisdictional waters and is not a jurisdictional impoundment. In other
                words, paragraph (b)(8) is designed to exclude artificial lakes and
                ponds that are constructed in upland or non-jurisdictional waters, even
                where they may have a surface water connection to a downstream
                jurisdictional water in a typical year.
                G. Adjacent Wetlands
                1. What are the agencies finalizing?
                 The agencies are finalizing a category of ``waters of the United
                States'' to include all adjacent wetlands to: The territorial seas and
                traditional navigable waters (paragraph (a)(1) waters); tributaries to
                those waters (paragraph (a)(2) waters); and lakes, ponds, and
                impoundments of jurisdictional waters (paragraph (a)(3) waters). In
                this final rule, the agencies define the term ``adjacent wetlands'' to
                mean wetlands that: (1) Abut a paragraph (a)(1) through (3) water; (2)
                are inundated by flooding from a paragraph (a)(1) through (3) water in
                a typical year; (3) are physically separated from a paragraph (a)(1)
                through (3) water only by a natural berm, bank, dune, or similar
                natural feature; or (4) are physically separated from a paragraph
                (a)(1) through (3) water only by an artificial dike, barrier, or
                similar artificial structure so long as that structure allows for a
                direct hydrologic surface connection between the wetlands and the
                paragraph (a)(1) through (3) water in a typical year, such as through a
                culvert, flood or tide gate, pump, or similar artificial feature. Under
                the final rule, an adjacent wetland is jurisdictional in its entirety
                when a road or similar artificial structure (i.e., not naturally
                occurring) divides the wetland, as long as the structure allows for a
                direct hydrologic surface connection through or over that structure in
                a typical year.
                 By retaining the term ``adjacent'' in the definition from the
                longstanding regulations, the agencies are continuing to use
                terminology that is familiar to the agencies and the regulated public.
                As proposed, however, the agencies are not including the terms
                ``bordering, contiguous, or neighboring'' from the previous regulations
                to reduce the potential confusion associated with using three seemingly
                similar terms in the same definition. See, e.g., U.S. General
                Accounting Office, Waters and Wetlands, GAO-04-297, at 10 (Feb. 2004)
                (``The regulations specify that adjacent means `bordering, contiguous,
                or neighboring'. . . . This definition of adjacency leaves some degree
                of interpretation to the Corps districts.''); see also id. at 3
                (``Districts apply different approaches to identify wetlands that are
                adjacent to other waters of the United States and are subject to
                federal regulation.''). Instead, the agencies use the term ``abut'' to
                clearly identify those waters that are inseparably bound up with other
                jurisdictional waters, in addition to the other clear tests for
                adjacency in this final rule.
                 The final rule adopts categorical tests for adjacency that are like
                those included in the proposal, but upon consideration of the public
                comments received, the agencies have enhanced the final definition to
                improve its clarity and ease of implementation, and to include
                additional wetlands that, upon further consideration, the agencies
                conclude should be subject to federal jurisdiction. Like the proposal,
                adjacent wetlands are those that abut or otherwise have a direct
                hydrologic surface connection to other covered waters in a typical
                year. But the agencies have modified the test to maintain jurisdiction
                over wetlands separated from other jurisdictional waters only by
                natural berms, banks, or dunes as those natural separations are
                evidence of a dynamic and regular direct hydrologic surface connection
                between the resources based on the agencies' technical expertise and
                experience. The agencies have also simplified and expanded the type of
                surface water connections that are not jurisdictional themselves but
                can nevertheless maintain jurisdictional connectivity between wetlands
                and other waters of the United States that are separated only by
                artificial dikes and other barriers. The agencies have also expanded
                jurisdiction, as compared to the proposal, over wetland complexes that
                are crossed by roads and similar structures if those structures allow
                for a surface water connection between the segregated wetland portions
                (such as through a culvert through a roadway) in a typical year.
                 Many commenters supported the proposal as establishing an
                appropriate balance between Federal and State jurisdiction over
                wetlands. Others stated that the proposal regulated too broadly. Still
                others asserted that the proposal too narrowly interpreted the
                agencies' CWA authorities and restricted jurisdiction over many
                ecologically important wetlands. The agencies have considered the
                diverse range of comments and are finalizing a rule that results in a
                balance of these competing views while adhering to the agencies'
                delegated authorities under the CWA and avoiding the outer limits of
                such authority.
                 Like the proposed rule, this final rule maintains the longstanding
                regulatory definition of ``wetlands'' in paragraph (c)(16) to mean
                ``those areas that are inundated or saturated by surface or ground
                water at a frequency and duration sufficient to support, and that under
                normal circumstances do support, a prevalence of vegetation typically
                adapted for life in saturated soil conditions. Wetlands generally
                include swamps, marshes, bogs, and similar areas.'' This is a well-
                established definition that is familiar to regulators, environmental
                consultants, and the scientific community. The agencies received many
                public comments urging them to maintain this definition, while certain
                other commenters suggested the agencies adopt different formulations.
                In this final rule, the agencies have retained the longstanding
                definition unchanged, as proposed.
                [[Page 22308]]
                 Consistent with the proposal, the agencies are finalizing a
                definition of ``upland'' to mean any land area above the ordinary high
                water mark or high tide line that does not satisfy all three wetland
                factors (i.e., hydrology, hydrophytic vegetation, and hydric soils
                \54\) under normal circumstances, as described in the Corps' 1987
                Wetlands Delineation Manual. Features that were once wetlands but have
                been naturally transformed or lawfully converted to upland (e.g., in
                compliance with a CWA section 404 permit) are considered upland under
                the final rule. For convenience, the agencies are including the
                existing Corps definitions for ``ordinary high water mark'' and ``high
                tide line'' from 33 CFR 328.3 in the EPA's regulations, as those terms
                are used in the final definition of ``upland.''
                ---------------------------------------------------------------------------
                 \54\ See Corps' 1987 Wetlands Delineation Manual at 9-10
                (``Wetlands have the following general diagnostic environmental
                characteristics: (1) Vegetation. The prevalent vegetation consists
                of macrophytes that are typically adapted to areas having hydrologic
                and soil conditions . . . Hydrophytic species, due to morphological,
                physiological, and/or reproductive adaptation(s), have the ability
                to grow, effectively compete, reproduce, and/or persist in anaerobic
                soil conditions. . . . (2) Soil. Soils are present and have been
                classified as hydric, or they possess characteristics that are
                associated with reducing soil conditions. . . . (3) Hydrology. The
                area is inundated either permanently or periodically at mean water
                depths https://www.epa.gov/npdes/interpretative-statement-releases-pollutants-point-sources-groundwater.
                ---------------------------------------------------------------------------
                Ephemeral Features and Diffuse Stormwater Run-Off
                 In paragraph (b)(3), the final rule excludes ephemeral features,
                including ephemeral streams, swales, gullies, rills, and pools. In
                paragraph (b)(4), the rule excludes diffuse stormwater run-off and
                directional sheet flow over upland. Such features are not
                jurisdictional under the terms of paragraph (a) in the final rule or
                its definitions in paragraph (c). They are specifically excluded in the
                final rule for additional clarity. The final rule differs from the
                proposed rule, as (b)(3) and (b)(4) were combined into one category of
                exclusions in the proposal. The agencies believe that separating the
                exclusions into two categories, as they have done for the final rule,
                provides greater clarity. The separation does not have a practical
                effect on or substantively change the types of waters and features that
                the final rule excludes compared to the proposed rule. As described in
                detail in Section III.A.3, the agencies have revised the proposed rule
                to clarify that while ephemeral features are not waters of the United
                States, a tributary does not lose its jurisdictional status if it
                contributes surface water flow to a downstream jurisdictional water in
                a typical year through a channelized ephemeral feature, such as an
                ephemeral stream or gully. However, if an upstream reach is connected
                to the downstream reach only by diffuse stormwater runoff or
                directional sheet flow over upland, the upstream reach is not
                jurisdictional under the final rule. Providing additional clarity in
                the paragraph (b) exclusions helps to highlight that only some excluded
                features are capable of providing a channelized surface water
                connection between upstream and downstream perennial or intermittent
                waters. Under the final rule, ephemeral features are not jurisdictional
                and do not become jurisdictional even if they maintain jurisdiction of
                relatively permanent upstream waters by conveying surface water from
                those waters to downstream jurisdictional waters in a typical year.
                 Some commenters supported the ephemeral features exclusion as being
                consistent with the CWA, Commerce Clause, and case law, particularly
                the plurality opinion in Rapanos. For example, one commenter indicated
                that the proposed exclusion aligned with CWA section 101(b) and, by
                avoiding jurisdiction over primarily dry features, did not
                significantly alter the Federal-State framework. Other commenters
                expressed concern that if they are not jurisdictional, ephemeral
                features could be subject to uncontrolled pollution or filled, and some
                commenters emphasized the potential adverse impacts to downstream
                jurisdictional waters into which ephemeral features flow.
                 By defining perennial and intermittent tributaries of traditional
                navigable waters as jurisdictional and defining ephemeral features as
                non-jurisdictional, and by including (b)(3) and (b)(4) exclusions
                explicitly emphasizing the non-jurisdictional status of ephemeral
                features and diffuse stormwater run-off, the agencies are balancing
                Congress' intent to interpret the term ``navigable waters'' more
                broadly than the classical meaning of that term and the notion that
                nothing in the legislative history of the Act ``signifies that Congress
                intended to exert anything more than its commerce power over
                navigation.'' SWANCC, 531 U.S. at 168 n.3. The exclusions in paragraphs
                (b)(3) and (b)(4) and the final rule's limitation of jurisdiction to
                perennial and intermittent rivers and streams most appropriately
                balances the Federal government's interest in regulating the nation's
                navigable waters with respecting State and Tribal land use authority
                over features that are only episodically wet during and/or following
                precipitation events. See, e.g., Rapanos, 547 U.S. at 734 (Scalia, J.,
                plurality) (identifying ``ephemeral streams'' and ``directional sheet
                flow during storm events'' as beyond the scope of CWA jurisdiction).
                 Some commenters raised concerns with potential adverse impacts to
                downstream jurisdictional waters from discharges to non-jurisdictional
                ephemeral features. The agencies believe that a CWA section 402
                permittee currently discharging to a jurisdictional water that becomes
                non-jurisdictional under this final rule would likely remain subject to
                the requirements of the Act. This specific concern was raised in
                Rapanos, that enforcement of section 402 could be frustrated by
                ``polluters . . . evad[ing] permitting requirement . . . by discharging
                their pollutants into noncovered intermittent watercourses that lie
                upstream of covered waters.'' Id. at 742-43. In the words of Justice
                Scalia, ``That is not so.'' Id. New or continuing discharges, whether
                illicit or not, could be subject to sections 301 and 402 of the Act if
                the discharge is conveyed from a point source to a ``water of the
                United States.'' The agencies view ephemeral features, such as arroyos
                or ditches, as potential conveyances of discharges of pollutants from
                point sources subject to NPDES permitting requirements. So too, the
                agencies believe, did Justice Scalia. He referred to ``channels''--a
                term used in the definition of ``point source'' at 33 U.S.C. 1362(14)--
                as ``ephemeral streams,'' ``dry arroyos in the middle of the desert,''
                and ``manmade drainage ditches'' when characterizing the types of
                features that he believed stretched the meaning of the ``term `waters
                of the United States' beyond parody.'' Id. at 734. Additional
                discussion of the final rule's treatment of ephemeral features is
                provided in Section III.A.3 of this notice.
                Ditches
                 The final rule's ditch exclusion in paragraph (b)(5) is intended to
                provide greater clarity for the regulated public and to be more
                straightforward for agency staff to implement than current practice.
                The agencies have incorporated a clear statement in the final rule that
                all types of ditches would be excluded except where they meet the
                conditions of paragraph (a)(1) or (2) of the final rule or where, in
                limited instances, they meet the conditions of paragraph (c)(1).
                Further, as discussed in Section III.D and Section III.E of this
                notice, the final rule clarifies that ditches are tributaries under
                paragraph (a)(2) where they relocate a tributary, are constructed in a
                tributary, or are constructed in an adjacent wetland, so long as the
                ditch satisfies the flow conditions of the ``tributary'' definition.
                Many States, regional groups, and national associations that commented
                during the Federalism consultation as part of development of the
                proposed rule and during the agencies' general outreach efforts noted
                that the definition of ``waters of the United States'' should exclude
                ditches. The agencies received further comments on the proposed rule's
                category of jurisdictional ditches and the exclusion for all other
                ditches. Some commenters argued that all ditches should be
                jurisdictional if they convey any volume of water to a covered water,
                however infrequent or insubstantial, while others took the opposite
                view. As discussed in Sections III.D. and III.E., the approach adopted
                in this final rule reasonably balances the exclusion of features that
                are fundamental to State, tribal, and local land use planning while
                respecting the need to preserve jurisdiction over certain ditches.
                [[Page 22320]]
                Prior Converted Cropland
                 The agencies are finalizing the prior converted cropland exclusion
                in paragraph (b)(6) and adding a definition of ``prior converted
                cropland'' in paragraph (c)(9). The definition of ``prior converted
                cropland'' clarifies that the exclusion is no longer applicable when
                the cropland is abandoned and the land has reverted to wetlands, as
                that term is defined in paragraph (c)(16). Under this final rule, prior
                converted cropland is considered abandoned if it is not used for, or in
                support of, agricultural purposes at least once in the immediately
                preceding five years. Agricultural purposes include land use that makes
                the production of an agricultural product possible, including but not
                limited to grazing and haying. Additional discussion on agricultural
                purposes is provided below. This final rule also clarifies that
                cropland that is left idle or fallow for conservation or agricultural
                purposes for any period or duration of time remains in agricultural use
                (i.e., it is used for, or in support of, agriculture purposes), and
                therefore maintains the prior converted cropland exclusion. The
                agencies conclude that this clarification will ensure that cropland
                enrolled in long-term and other conservation programs administered by
                the Federal government or by State and local agencies that prevents
                erosion or other natural resource degradation does not lose its prior
                converted cropland designation as a result of implementing conservation
                practices.
                 In 1993, the agencies categorically excluded prior converted
                cropland from the definition of ``waters of the United States.'' 58 FR
                45034-36 (August 25, 1993). As further explained below, in keeping with
                the Food Security Act of 1985 (FSA), the 1993 preamble defined prior
                converted cropland as ``areas that, prior to December 23, 1985, were
                drained or otherwise manipulated for the purpose, or having the effect,
                of making production of a commodity crop possible [and that are]
                inundated for no more than 14 consecutive days during the growing
                season.'' 58 FR 45031. As explained in detail in the 1993 preamble, due
                to the degraded and altered nature of prior converted cropland, the
                agencies determined that such lands should not be treated as
                jurisdictional wetlands for purposes of the CWA because regulating such
                lands does not further the objective of the Act. 58 FR 45032. The 1993
                preamble also set out a mechanism to ``recapture'' prior converted
                cropland into the section 404 program when the land has been abandoned
                and wetland features return. 58 FR 45034. This approach is consistent
                with the principles in the 1990 Corps Regulatory Guidance Letter 90-7.
                Although included in the 1993 preamble and Regulatory Guidance Letter
                90-7, these principles have not been incorporated into the text of any
                promulgated rule until now. This rule therefore represents the first
                time the agencies are promulgating regulatory language to clarify the
                meaning of ``prior converted cropland'' for CWA purposes, the
                application of the exclusion, and a recapture mechanism based on
                abandonment and reversion to wetlands.
                 Historically, the agencies have attempted to create consistency
                between the CWA and the FSA wetlands conservation provisions for prior
                converted cropland. The agencies continue to believe that consistency
                across these programs is important for the regulated community (see 58
                FR 45033), and therefore are continuing to exclude prior converted
                cropland from the definition of ``waters of the United States.'' By
                incorporating the abandonment principles from the 1993 preamble and
                providing examples of ``agricultural purposes,'' this final rule
                remains consistent with the concepts underlying the FSA but differs in
                implementation from certain aspects of USDA's current wetlands
                compliance authority. Incorporating the abandonment principle, as
                opposed to a pure ``change in use'' policy (described below), is
                important for the agencies to appropriately manage certain wetland
                resources while providing better clarity to the agricultural community.
                 When the 1993 preamble was published, the abandonment principle was
                consistent with USDA's implementation of the FSA. Three years later,
                the 1996 FSA amendments modified the abandonment principle and
                incorporated a ``change in use'' policy. See Public Law 104-127, 110
                Stat. 888 (1996). Under the new policy, prior converted cropland would
                continue to be treated as such even if wetland characteristics returned
                because of lack of maintenance of the land or other circumstances
                beyond the owner's control, ``as long as the prior converted cropland
                continues to be used for agricultural purposes.'' H.R. 2854, Conf. Rep.
                No. 104-494, at 380 (1996). In 2005, the Corps and NRCS issued a joint
                ``Memorandum to the Field'' (the 2005 Memorandum) in an effort to again
                align the CWA section 404 program with the FSA by adopting the amended
                FSA's change in use policy. The 2005 Memorandum provided that, a
                ``certified [prior converted] determination made by [USDA] remains
                valid as long as the area is devoted to an agricultural use. If the
                land changes to a non-agricultural use, the [prior converted cropland]
                determination is no longer applicable, and a new wetland determination
                is required for CWA purposes.'' \57\
                ---------------------------------------------------------------------------
                 \57\ Memorandum to the Field on Guidance on Conducting Wetland
                Determinations for the Food Security Act of 1985 and section 404 of
                the Clean Water Act, February 25, 2005, available at https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2508.
                ---------------------------------------------------------------------------
                 The 2005 Memorandum did not clearly address the abandonment
                principle that the agencies had been implementing since the 1993
                rulemaking. The change in use policy articulated in the 2005 Memorandum
                was also never promulgated as a rule and was declared unlawful by one
                district court because it effectively modified the 1993 preamble
                language without any formal rulemaking process. See New Hope Power Co.
                v. U.S. Army Corps of Eng'rs, 746 F. Supp. 2d 1272, 1282 (S.D. Fla.
                2010). Implementing the 2005 Memorandum created other challenges for
                the agencies and the regulated community. For example, because the 2005
                Memorandum did not clearly address whether or how the abandonment
                principles should be applied in prior converted cropland cases, neither
                the agencies nor the regulated community could be certain which
                approach would be applied to a specific case.
                 The agencies received many public comments on the prior converted
                cropland exclusion, with some commenters noting that the exclusion will
                provide clarification needed to protect prior converted cropland that
                may be subject to flooding and to other natural occurrences that result
                in wet or saturated fields. The agencies also received public comments
                on both the abandonment principle and the change in use analysis. Some
                commenters supported the abandonment principle, stating, for example,
                that prior converted cropland should lose its status only when the land
                is abandoned and the area reverts back to wetland. Other commenters
                requested that the agencies finalize the change in use analysis, as
                articulated in the 2005 Memorandum. The agencies have considered these
                comments and for the reasons provided herein are finalizing the
                abandonment principle as proposed and are not adopting the change in
                use approach.
                 The agencies received many comments in support of the term ``for or
                in support of, agricultural purposes'' and recommendations as to how
                the term should be interpreted. Commenters
                [[Page 22321]]
                requested that the agencies provide additional examples of agricultural
                purposes, including, but not limited to, idling land for conservation
                uses (e.g., habitat; pollinator and wildlife management; and water
                storage, supply, and flood management); irrigation tailwater storage;
                crawfish farming; cranberry bogs; nutrient retention; and idling land
                for soil recovery following natural disasters like hurricanes and
                drought. The uses listed above, in addition to crop production, haying,
                and grazing, fall within the term ``agricultural purposes'' and, if
                documented, may maintain the prior converted cropland exclusion.
                Conservation practices, including those required or supported by USDA,
                State, and local programs (including recognized private sector programs
                that partner with government programs or that can provide verifiable
                documentation of participation) are critical to the success of
                agricultural systems across the country. Conservation practices and
                programs also are conducted ``for or in support of agricultural
                purposes'' and are appropriate to maintain the prior converted cropland
                exclusion.
                 The agencies also received public comment on the type of
                documentation that a landowner should maintain to demonstrate that
                cropland has been used ``for or in support of, agricultural purposes.''
                Commenters suggested the use of aerial photographs, topographical maps,
                cultivation maps, crop expense or receipt records, field- or tract-
                specific grain elevator records, and other records generated and
                maintained in the normal course of doing business. The agencies agree
                that these types of documents and other documentation reasonably
                establishing ``agricultural purposes'' are appropriate to demonstrate
                that the prior converted cropland exclusion applies to a certain field
                or tract of land.
                 Finally, the agencies received public comments on whether the five-
                year timeframe for maintaining agricultural purposes is appropriate.
                Some commenters supported the five-year timeframe. Other commenters
                thought that five years was too long to avoid federal jurisdiction if
                wet cropland was providing some ecological or habitat benefit that
                should be maintained. Other commenters thought that the five-year
                timeframe was too short to account for unforeseen circumstances that
                could leave cropland idle for longer periods of time (e.g., bankruptcy,
                the probate and estate administration process, natural disasters), and
                recommended that the agency adopt a seven, ten, or twenty-year
                timeframe. Some commenters specifically requested that the agencies
                allow more than five years when drought or flood conditions prevent
                cultivation, planting or harvest. The agencies have considered these
                comments and conclude that a five-year timeframe for maintaining
                agricultural purposes is reasonable and consistent with the 1993
                preamble (58 FR 45033) and with the five-year timeframe regarding
                validity of an approved jurisdictional determination (2005 Corps
                Regulatory Guidance Letter (RGL) 05-02). The five-year timeframe is
                longstanding in the CWA section 404 program and will be familiar to
                landowners and regulators alike, increasing clarity in implementation.
                The agencies are finalizing the rule with the five-year timeframe, as
                proposed, but as described in the next subsection, the agencies will
                work closely with USDA, and will consider documentation from USDA,
                NOAA, FEMA, or other Federal or State agencies to determine if the land
                was used for or in support of agricultural purposes in the immediately
                preceding five years to evaluate whether cropland has in fact been
                abandoned.
                 The agencies consider rulemaking to be appropriate here in order to
                clarify the definition of ``prior converted cropland'' and to provide
                regulatory certainty over when such lands are no longer eligible for
                the CWA exclusion. This final rule provides much needed clarity about
                the prior converted cropland exclusion and how wetlands can be
                recaptured into CWA jurisdiction through the abandonment test. In
                addition to finalizing the exclusion as proposed, the Corps will
                withdraw the 2005 Memorandum simultaneous with the effective date of
                this rule.
                Artificially Irrigated Areas, Artificial Lakes and Ponds, and Water-
                Filled Depressions
                 Paragraph (b) also excludes from waters of the United States under
                this final rule:
                 Artificially irrigated areas, including fields flooded for
                agricultural production, that would revert to upland should application
                of irrigation water to that area cease (paragraph (b)(7));
                 Artificial lakes and ponds, including water storage
                reservoirs and farm, stock watering, and log cleaning ponds,
                constructed or excavated in upland or in non-jurisdictional waters, so
                long as those artificial lakes and ponds are not impoundments of
                jurisdictional waters that meet the conditions of paragraph (c)(6)
                (paragraph (b)(8)); and
                 Water-filled depressions constructed or excavated in
                upland or in non-jurisdictional waters incidental to mining or
                construction activity, and pits excavated in upland or in non-
                jurisdictional waters for the purpose of obtaining fill, sand, or
                gravel (paragraph (b)(9)).
                 Paragraphs (b)(7), (8), and (9) of the final rule identify features
                and waters that the agencies have generally excluded from the
                definition of ``waters of the United States'' in previous preambles
                since 1986 (see, e.g., 51 FR 41206, 41217 (November 13, 1986) and 53 FR
                20764-65 (June 6, 1988)). The agencies have codified these longstanding
                exclusions to further the agencies' goals of providing greater clarity
                and predictability for the regulated public and the regulators.
                 Several of these exclusions use the phrase ``upland.'' In keeping
                with the goal of providing greater clarity, the agencies have included
                in the final rule a definition of ``upland'' in paragraph (c)(14). It
                is important to note that a water of the United States is not
                considered ``upland'' just because it lacks water at a given time.
                Similarly, an area may remain ``upland'' even if it is wet sporadically
                or after a rainfall or flood event. In addition, the agencies recognize
                that excluded water features may be constructed or excavated in non-
                jurisdictional ponds, wetlands, or other non-jurisdictional features.
                Therefore, the agencies added the phrase ``non-jurisdictional waters''
                to some of these exclusions to provide greater clarity and to confirm
                that these features can be constructed or excavated in a non-
                jurisdictional water, such as an isolated pond or wetland, while
                continuing to be excluded from federal jurisdiction.
                 The upland requirement does not apply to all exclusions under
                paragraph (b). For those waters or features in paragraph (b) of this
                final rule that do contain the stipulation that they must be
                constructed or excavated in upland or in non-jurisdictional waters to
                be excluded, the agencies intend that these features be constructed or
                excavated wholly in upland or in non-jurisdictional waters. For
                example, construction activities that enlarge a water of the United
                States beyond its current boundaries are not constructed wholly in
                upland. Where portions of a new or modified water feature are built in
                a jurisdictional water, the agencies would not view the new or modified
                feature as having been constructed or excavated wholly in upland or in
                non-jurisdictional waters, and therefore not subject to the exclusion.
                But where a stock watering pond, for example, is developed in a spring
                that is non-jurisdictional under this final rule, that pond will be
                considered by the agencies to have been constructed wholly in
                [[Page 22322]]
                upland and/or non-jurisdictional waters. Even if a feature is not
                constructed or excavated wholly in upland or in non-jurisdictional
                waters and meets the definition of ``waters of the United States,'' it
                may be otherwise excluded under another part of paragraph (b). The
                agencies note, however, that the mere interface between the excluded
                feature constructed or excavated wholly in upland and a jurisdictional
                water does not make that feature jurisdictional. For example, a ditch
                constructed or excavated wholly in upland that connects to a tributary
                would not be considered a jurisdictional ditch. The connection to a
                jurisdictional water does not eliminate applicability of a paragraph
                (b) exclusion conditioned by the upland or non-jurisdictional waters
                language. To avoid any confusion in implementation, this is why the
                agencies have not included the term ``wholly'' in the final regulatory
                text. Finally, an excluded feature under the final rule that develops
                wetland characteristics within the confines of the non-jurisdictional
                water or feature remains excluded from the definition of ``waters of
                the United States,'' with the exception in limited circumstances of
                wetlands that develop in ditches constructed in adjacent wetlands, as
                discussed in Section III.G.
                 Many commenters were in favor of the proposed exclusion under
                (b)(6) of the proposed rule, now under (b)(7), for artificially
                irrigated areas. A few commenters were opposed to the exclusion
                entirely, and some commenters were opposed to expanding the exclusion
                for other crops and/or aquaculture. Some commenters cited the need for
                clarity as to whether the listed crops were the only ones covered under
                the exclusion. After considering the comments received, the agencies
                have modified this exclusion in the final rule to clarify their intent
                that it is not limited to rice and cranberry production and applies
                more generally to ``agricultural production.'' The references to
                cranberries and rice in the proposed rule were examples and were not an
                exhaustive list of crops to which the exclusion would apply. When
                evaluating an area to determine whether it meets the exclusion, the
                focus should be on whether the area is artificially irrigated or
                flooded for the purpose of agricultural production and on whether it
                would revert to upland if the irrigation ceases.
                 Paragraph (b)(8) of the final rule provides that artificial lakes
                and ponds, including water storage reservoirs and farm, irrigation,
                stock watering, and log cleaning ponds, are excluded from the
                definition of ``waters of the United States'' so long as these features
                are constructed or excavated in upland or in non-jurisdictional waters,
                and so long as these features are not impoundments of jurisdictional
                waters meeting the conditions of paragraph (c)(6). Many commenters
                provided edits and additions to the list of water features included in
                paragraph (b)(8). However, the agencies did not intend to provide an
                exhaustive list of features that are excluded under paragraph (b)(8)
                and have determined that any feature that meets the conditions of
                paragraph (b)(8) will be non-jurisdictional under this rule.
                 The agencies modified the proposed exclusion for artificial lakes
                and ponds to clarify their intent. As drafted in the proposed rule, the
                exclusion unintentionally would have been narrower than under the 1980s
                regulations. For example, when a farm pond is constructed in upland and
                connected via a ditch also constructed in upland to divert flow from a
                tributary and the farm pond does not connect back into the tributary
                system, it has been longstanding agency practice that the farm or stock
                pond is non-jurisdictional, similar to irrigation ditches which do not
                connect back into the tributary network. The pond's source of water is
                the tributary and serves to provide water for irrigation, livestock,
                and other agricultural uses. Because such ponds do not contribute
                surface water flow to a downstream paragraph (a)(1) water, they have
                not been jurisdictional under historic practice and are not
                jurisdictional under this final rule. Another example involves a stock
                watering pond developed in a non-jurisdictional spring. If that pond
                has a spillway that creates a potential surface water connection to a
                nearby stream, the pond has traditionally been excluded from CWA
                jurisdiction. This final rule adopts that longstanding position.
                 In the final rule, the agencies are clarifying that artificial
                features including water storage reservoirs and farm, irrigation, stock
                watering, and log cleaning ponds are not jurisdictional unless they are
                impoundments of jurisdictional waters meeting the conditions of
                paragraph (c)(6), as discussed in Section III.F of this notice. The
                agencies acknowledge that many artificial lakes and ponds may have been
                created by impounding other waters. The text of the final rule
                clarifies that artificial lakes and ponds that also meet the conditions
                of a jurisdictional impoundment under paragraph (c)(6) are not excluded
                under paragraph (b)(8). However, consistent with longstanding practice,
                when an applicant receives a permit to impound a water of the United
                States in order to construct a waste treatment system (as excluded
                under paragraph (b)(12)), under this final rule the agencies are
                affirmatively relinquishing jurisdiction over the resulting waste
                treatment system as long as it is used for this permitted purpose. Also
                consistent with longstanding practice, waters upstream of the waste
                treatment system are still considered jurisdictional where they meet
                the final rule's definition of ``waters of the United States.''
                 The (b)(8) exclusion for artificial lakes and ponds uses the term
                ``constructed or excavated'' in the final rule, while the proposed rule
                used the term ``constructed.'' The agencies do not intend for this
                change to alter the meaning of the exclusion from proposal. The
                agencies believe that this edit provides clarity to the public about
                how excluded artificial lakes and ponds can be created--some are
                constructed through dams, dikes, or barriers, while some are excavated
                pits. Excavation can entail construction, and construction can entail
                excavation, but the agencies have decided to use both terms in the
                final rule for added clarity.
                 Several commenters stated that artificial lakes and ponds should be
                excluded regardless of whether they are located either wholly or
                partially in upland, and that the (b)(8) exclusion should extend to
                artificial lakes and ponds not constructed or excavated in upland. A
                few commenters noted that farmers and ranchers often determine the
                location of farm and stock ponds based on topography, which will
                typically result in the construction of such features in low areas that
                may have some characteristics of wetlands or a natural ephemeral
                feature. One commenter noted that many artificial lakes or ponds are
                isolated features, and that their connectivity to waters of the United
                States rather than their relationship to upland should be the primary
                factor in determining jurisdiction.
                 The final rule continues to require an artificial lake or pond to
                be constructed or excavated wholly in upland or in non-jurisdictional
                waters to be considered excluded under (b)(8). This reflects the
                agencies' longstanding policy, as discussed above with the stock
                watering pond example. Artificial lakes and ponds constructed or
                excavated partially in uplands or in non-jurisdictional waters and
                partially in jurisdictional waters are jurisdictional if such lakes and
                ponds meet the conditions of paragraph (c)(6). The agencies are
                concerned that if only
                [[Page 22323]]
                part of an artificial lake or pond need be in upland, the exclusion
                could be inappropriately applied to waters where just a small portion
                is constructed in upland. The agencies again note that the mere
                interface between the excluded lake or pond otherwise constructed or
                excavated wholly in upland and a jurisdictional water does not make
                that feature jurisdictional. For example, an artificial lake or pond
                that meets the conditions of paragraph (b)(8) and that connects to a
                tributary would not be considered jurisdictional. With respect to
                artificial lakes and ponds that are constructed in isolated or
                ephemeral features, the agencies modified the exclusion to make clear
                that artificial lakes or ponds constructed or excavated in non-
                jurisdictional features are excluded.
                 Paragraph (b)(9) of the final rule excludes water-filled
                depressions constructed or excavated in upland or in non-jurisdictional
                waters incidental to mining or construction activity, and pits
                excavated in upland or in non-jurisdictional waters for the purpose of
                obtaining fill, sand, or gravel. In this final rule, the agencies have
                modified this exclusion from the proposal. In the proposed rule, such
                depressions would have been excluded where they are ``created in
                upland,'' but in the final rule such depressions are excluded where
                they are ``constructed or excavated in upland or in non-jurisdictional
                waters.'' The change from ``created'' to ``constructed or excavated,''
                as discussed above, is not meant to change the meaning or applicability
                of the exclusion from the proposed rule, but rather is intended to add
                clarity to the regulated public about how such excluded water-filled
                depressions can be created.
                 Aside from this clarifying change, the agencies are finalizing this
                exclusion as it was proposed. In the final rule, this exclusion
                clarifies longstanding practice reflected in the agencies' 1986 and
                1988 preambles, 51 FR 41206, 41217 (November 13, 1986); 53 FR 20764-65
                (June 6, 1988) and includes several refinements to the language in
                those preambles. In addition to construction activity, the agencies
                have also reflected in the final rule an exclusion for water-filled
                depressions created in upland incidental to mining activity. This is
                consistent with the 1986 and 1988 preambles, which generally excluded
                pits excavated for obtaining fill, sand, or gravel, and the agencies
                believe there is no need to distinguish between features based on
                whether they are created by construction or mining activity.
                 Several commenters supported the (b)(9) exclusion, because such
                water-filled depressions are often needed for facility management but
                are not part of the tributary system and are not natural waters. Some
                commenters opposed the exclusion, stating that the exclusion benefited
                mining companies and would allow mining activities to negatively impact
                water quality. Other commenters stated that the exclusion should be
                expanded to include water-filled depressions constructed or excavated
                incidental to other activities such as silviculture, or incidental to
                all activities, asserting that the agencies should not have singled out
                specific industries in the exclusion. With respect to expanding the
                exclusion to encompass additional industries or activities, the
                agencies note that the (b)(9) exclusion is not the only one that
                addresses artificial waters. Paragraph (b) of the final rule excludes a
                number of artificial features not limited to specific industries. In
                addition, CWA section 404(f) exempts a number of discharges associated
                with certain activities in jurisdictional waters from the requirement
                to obtain a section 404 permit, including normal farming, ranching, and
                silviculture activities as part of an established operation. 33 U.S.C.
                1344(f)(1)(A).
                 Some commenters wanted the (b)(9) exclusion to be expanded so that
                once a water-filled depression was excluded, it remained excluded for
                CWA section 404 purposes. The 1986 and 1988 preambles stated that these
                depressions were excluded ``unless and until the construction or
                excavation operation is abandoned and the resulting body of water meets
                the definition of waters of the United States.'' (51 FR 41206, 41217
                (November 13, 1986); 53 FR 20764-65 (June 6, 1988)). The agencies
                proposed that such water-filled depression would remain excluded, which
                represented a change from the 1986 and 1988 preamble language. After
                further consideration, and after considering comments received, the
                agencies have concluded that once a feature subject to the (b)(9)
                exclusion is no longer used for the original purpose for which it was
                excluded, it no longer qualifies for the (b)(9) exclusion. This is
                consistent with the approach to other exclusions, such as waste
                treatment systems and artificially irrigated areas, and reaffirms the
                agencies' longstanding practice regarding this exclusion. In many
                cases, even if the (b)(9) exclusion may no longer apply to a feature,
                the feature may still remain non-jurisdictional because it does not
                meet the conditions of paragraphs (a)(1) through (4) and thus is
                excluded under paragraph (b)(1).
                Stormwater Control Features
                 In paragraph (b)(10) of the final rule, the agencies exclude
                stormwater control features constructed or excavated in upland or in
                non-jurisdictional waters to convey, treat, infiltrate, or store
                stormwater runoff. Although stormwater control features are not
                specifically included in the list of waters that the agencies consider
                to be generally non-jurisdictional per the 1986 and 1988 preamble
                language, 51 FR 41206 (November 13, 1986) and 53 FR 20764 (June 6,
                1988), the agencies' longstanding practice is to view stormwater
                control features that are not built in waters of the United States as
                non-jurisdictional. Conversely, the agencies view some relatively
                permanent bodies of water, such as channelized streams with
                intermittent or perennial flow, as jurisdictional even when used as
                part of a stormwater management system. Nothing in this final rule
                changes the agencies' longstanding practice. Rather, this exclusion
                clarifies the appropriate limits of jurisdiction relating to these
                systems.
                 A key element of the exclusion is whether the feature or control
                system was built wholly in upland or in a non-jurisdictional water. As
                discussed above and as further clarified below, the agencies recognize
                that upland features may be connected to jurisdictional waters and that
                such a connection does not preclude application of the exclusion.
                Another key element is that the feature must convey, treat, infiltrate,
                or store stormwater. Stormwater control features have evolved
                considerably over time, and their nomenclature is not consistent, so in
                order to avoid unintentionally limiting the exclusion, the agencies
                have not included a list of excluded features in the final rule. The
                rule excludes the diverse range of stormwater control features that are
                currently in place and may be developed in the future. However, the
                agencies note that excluded stormwater control features when they have
                channelized surface water may provide a connection between the upstream
                reach of a relatively permanent water and a downstream jurisdictional
                water such that the upstream reach is jurisdictional. Even in this
                circumstance, the stormwater control feature would remain non-
                jurisdictional under this final rule. See Section III.D of this notice
                for further discussion. The agencies also note that while excluded from
                the definition of ``waters of the United States,'' stormwater control
                features may function as a conveyance of a discharge of pollutants from
                a point source to a water of the United States.
                [[Page 22324]]
                 Traditionally, stormwater controls were designed to direct runoff
                away from people and property as quickly as possible. Cities built
                systems to collect, convey, or store stormwater, using structures such
                as curbs, gutters, and sewers. Retention and detention stormwater ponds
                were built to store excess stormwater until it could be more safely
                released. More recently, use of stormwater controls to remove
                pollutants before the stormwater is discharged has become more
                prevalent. Even more recently, cities have turned to green
                infrastructure, using existing natural features or creating new
                features that mimic natural hydrological processes that work to
                infiltrate, evaporate, or transpire precipitation, to manage stormwater
                at its source and keep it out of the conveyance system. These
                engineered components of stormwater management systems can address both
                flood control and water quality concerns, as well as provide other
                benefits to communities. This final rule is designed to avoid
                disincentives to this environmentally beneficial trend in stormwater
                management practices.
                 Many commenters supported the proposed rule's exclusion for
                stormwater control features constructed or excavated in upland,
                asserting that environmentally beneficial solutions to manage
                stormwater could be discouraged if such features were designated as
                ``waters of the United States.'' Several commenters noted concerns that
                an exclusion dependent on an upland location could potentially deter
                stormwater system operators from installing beneficial green
                infrastructure and suggested that jurisdictional waters incorporated
                into the stormwater system should be excluded. Many commenters
                suggested that the final rule should define ``stormwater control
                features'' that would be excluded.
                 The agencies' longstanding practice is to view stormwater control
                features as non-jurisdictional when built outside of waters of the
                United States. The agencies do not agree with commenters who stated
                that jurisdictional waters that are incorporated into a drainage or
                stormwater conveyance system should be excluded by virtue of the fact
                that they are part of the larger stormwater control system. A water
                does not lose its jurisdictional status if it is modified for use as a
                stormwater control measure. The agencies recognize that highly
                engineered municipal separate storm sewer systems (MS4s) that may have
                replaced natural drainage features may therefore have jurisdictional
                waters within their systems, but this does not represent a change from
                longstanding practice. For example, the Los Angeles River is a
                traditional navigable water highly engineered for stormwater control,
                and it still meets the requirements of a paragraph (a)(1) water.
                Regarding comments related to defining the term ``stormwater control
                features,'' the agencies do not name specific stormwater control
                features that would fall under the stormwater control feature
                exclusion, as they do not want the final rule to be perceived as
                limiting the exclusion, particularly given differences among regional
                naming conventions and the likelihood that technologies and
                nomenclature will evolve in the future.
                Groundwater Recharge, Water Reuse, and Wastewater Recycling Structures
                 In this final rule under paragraph (b)(11), the agencies exclude
                from the definition of ``waters of the United States'' groundwater
                recharge, water reuse, and wastewater recycling structures constructed
                or excavated in upland or in non-jurisdictional waters. While such
                features are not explicitly listed in the categories of waters that the
                agencies generally consider to be non-jurisdictional in the 1986 and
                1988 preamble language, 51 FR 41206 (November 13, 1986) and 53 FR 20764
                (June 6, 1988), this exclusion clarifies the agencies' longstanding
                practice that waters and water features used for water reuse and
                recycling are not jurisdictional when constructed in upland or in non-
                jurisdictional waters. The agencies recognize the importance of water
                reuse and recycling, particularly in the arid West where water supplies
                can be limited and droughts can exacerbate supply issues. This
                exclusion is intended to avoid discouraging or creating barriers to
                water reuse and conservation practices and projects. Detention and
                retention basins can play an important role in capturing and storing
                water prior to beneficial reuse. Similarly, groundwater recharge basins
                and infiltration ponds are becoming more prevalent tools for water
                reuse and recycling. These features are used to collect and store
                water, which then infiltrates into groundwater via permeable soils.
                Though these features are often created in upland, they are also often
                located in close proximity to tributaries or other larger bodies of
                water. The exclusion in paragraph (b)(11) of the final rule codifies
                the agencies' longstanding practice and encourages water management
                practices that the agencies recognize are important and beneficial.
                 Many commenters expressed support for the proposed rule's exclusion
                for wastewater recycling structures. Some commenters stated that the
                exclusion would encourage water reuse and other innovative approaches
                to water management. A few commenters supported the exclusion because
                they said wastewater recycling structures should be regulated at the
                State level. Some commenters stated that considering a wastewater
                recycling structure a water of the United States could create
                unnecessary regulatory and economic burdens, while providing no
                additional water quality protection. Several commenters stated that the
                exclusion of groundwater recharge basins and similar structures was
                consistent with Justice Scalia's plurality opinion in Rapanos, as
                groundwater recharge basins do not discharge to any navigable waters,
                are filled only during part of the year, and do not otherwise
                constitute a traditional navigable water within the meaning of the
                plurality's jurisdictional test. A number of commenters suggested that
                the qualifying language in the proposed rule's wastewater recycling
                structures exclusion, which would have limited the exclusion to
                wastewater recycling structures ``constructed in upland,'' could create
                barriers to water reuse and conservation.
                 For the reasons described above, the agencies believe that the
                (b)(11) exclusion reflects an appropriate balance among CWA policies
                and encouraging water reuse and effective water management. As a
                result, this final rule includes the (b)(11) exclusion largely
                unchanged from the proposal. The agencies did modify the exclusion in
                response to comments to add the term ``water reuse'' to the exclusion
                as it is commonly used in water and wastewater management. The agencies
                also added ``or non-jurisdictional waters'' to the exclusion to ensure
                that it is not narrowly restricted to construction in upland only. As
                discussed above, the agencies will apply the qualifier ``constructed or
                excavated in upland or in non-jurisdictional waters'' consistently
                across four exclusions that use the term.
                Waste Treatment Systems
                 Paragraph (b)(12) of the final rule excludes waste treatment
                systems. The waste treatment system exclusion has existed since 1979
                (44 FR 32854), and the agencies are continuing the exclusion under this
                final rule. The agencies are also for the first time providing in the
                final rule a definition of ``waste treatment system'' under paragraph
                (c)(15), so as to clarify which waters and features are considered part
                of a waste treatment system and therefore excluded. Continuing the
                agencies' longstanding practice, any
                [[Page 22325]]
                entity with a waste treatment system would need to comply with the CWA
                by obtaining a section 404 permit for new construction in a water of
                the United States, and a section 402 permit for discharges from the
                waste treatment system into waters of the United States. Consistent
                with the proposal, the agencies intend for this exclusion to apply only
                to waste treatment systems constructed in accordance with the
                requirements of the CWA and to all waste treatment systems constructed
                prior to the 1972 CWA amendments. One ministerial change in the final
                rule from the 2019 Rule is the deletion of a cross-reference to a
                regulatory definition of ``cooling ponds'' that no longer exists in the
                Code of Federal Regulations.\58\
                ---------------------------------------------------------------------------
                 \58\ See 47 FR 52290, 52291, 52305 (Nov. 19, 1982) (deleting
                definition of cooling ponds at 40 CFR 423.11(m)).
                ---------------------------------------------------------------------------
                 Many commenters supported the waste treatment system exclusion and
                definition as proposed and agreed that the proposed exclusion would
                codify the agencies' longstanding practice. Some commenters requested
                that the exclusion be expanded to include all ancillary systems,
                channels, appurtenances, conveyances, and diversion ditches associated
                with the waste treatment system. Other commenters stated that the
                proposed exclusion was unlawful and that it should be eliminated
                entirely. Some commenters suggested that there may be confusion
                concerning the agencies' intent to apply the exclusion to waste
                treatment systems constructed prior to the 1972 CWA amendments and
                requested that this concept be explicitly included in the final
                regulatory text.
                 The agencies have considered these public comments and have
                finalized the waste treatment exclusion as it was proposed. As noted
                above, the agencies agree with commenters that this final rule codifies
                the longstanding exclusion that was first included in regulation in
                1979. The agencies disagree with suggestions to expand or eliminate the
                exclusion and have finalized the definition as proposed. The agencies
                also disagree with the suggestion that the exclusion is unlawful and
                that there is confusion over the agencies' intent to apply this
                exclusion to all waste treatment systems constructed prior to the 1972
                CWA amendments. The agencies clearly stated their intent to do so in
                the notice of proposed rulemaking and in this final rule, and do not
                believe it is necessary to repeat this intent in the regulatory text.
                The regulatory text applies to all waste treatment systems that meet
                the definition set forth therein, including systems constructed prior
                to the 1972 CWA amendments, and there is no basis for construing the
                exclusion not to apply to such systems.
                 The agencies also considered other exclusions recommended by
                stakeholders prior to the proposed rule and suggested in comments on
                the proposed rule. The agencies did not include these additional
                proposed exclusions in the final rule. Some of the suggested exclusions
                were so broadly characterized that they would have introduced confusion
                and potentially excluded waters that the agencies have consistently
                determined should be covered as waters of the United States. Other
                suggested exclusions were so site-specific or activity-based that they
                did not warrant inclusion in the nationally-applicable definition.
                Still other suggested exclusions were covered by another exclusion in
                the rule, and thus would have been superfluous, in whole or in part.
                3. How will the agencies implement the final rule?
                 To determine whether a water meets the final rule's exclusions in
                paragraphs (b)(1) through (b)(12), the agencies will first evaluate
                whether the water meets the definition of ``waters of the United
                States'' under paragraphs (a)(1) through (4). If the water does not
                satisfy any of the paragraph (a)(1) through (4) conditions, it is non-
                jurisdictional under paragraph (b)(1). If the water does satisfy one or
                more of the conditions to be a paragraph (a)(1) through (4) water, the
                agencies will evaluate if the water is identified in any of the
                categories of excluded waters and features under paragraphs (b)(2)
                through (12) of this final rule. If the water meets any of these
                exclusions, the water is excluded even if the water satisfies one or
                more of the conditions to be a paragraph (a)(1) through (4) water.
                 As discussed above, the agencies' final rule includes an exclusion
                for groundwater under paragraph (b)(2), including groundwater drained
                through subsurface drainage systems. The final rule clarifies that even
                when groundwater is channelized in subsurface systems, like tile drains
                used in agriculture, it remains subject to the exclusion. However, the
                exclusion does not apply to surface expressions of groundwater, such as
                where groundwater discharges to the channel bed and becomes baseflow in
                intermittent or perennial streams. The agencies' exclusion for
                groundwater in the final rule is consistent with longstanding agency
                practice.
                 Some commenters requested that the agencies provide guidance as to
                how to implement the exclusion for ephemeral features. For example, a
                commenter stated that a blanket exclusion of ephemeral streams without
                regard to flow quantity could increase the difficulty in delineating
                such features and could limit activities to certain time periods. Some
                commenters suggested the agencies consider certain ephemeral features
                to be jurisdictional on a situational or regional basis, while other
                commenters supported a case-by-case determination of ephemeral features
                that would fall under the exclusion, rather than excluding ephemeral
                features categorically. One commenter requested implementation tools,
                including visual aids or benchmarks to identify excluded features,
                observing that distinguishing between ephemeral and intermittent waters
                may be challenging.
                 This final rule is intended to establish categorical bright lines
                that provide clarity and predictability for regulators and the
                regulated community. Consistent with that goal, the final rule
                eliminates the case-specific application of Justice Kennedy's
                significant nexus test, and instead establishes clear categories of
                jurisdictional waters and non-jurisdictional waters and features that
                adhere to the basic principles articulated in the Riverside Bayview,
                SWANCC, and Rapanos decisions, including key principles expressed in
                Justice Scalia's plurality opinion and Justice Kennedy's concurring
                opinion in that case, as discussed at length in this preamble, while
                respecting the overall structure and function of the CWA. The agencies
                have existing field and remote tools and additional implementation
                tools and methods under development that will help distinguish flow
                classifications of streams and other waterbodies. The agencies can use
                many tools and remote and field-based methods described in Section
                III.D.3 to distinguish between paragraph (b)(3) ephemeral streams,
                swales, gullies, rills, and pools and paragraph (b)(4) areas with
                diffuse stormwater run-off and directional sheet flow over upland,
                while comparing both against waters subject to jurisdiction under
                paragraph (a). Under past and existing practice, the agencies have
                substantial experience using remote tools and field observations to
                distinguish between channelized and non-channelized features, and the
                agencies expect that many landowners can distinguish between these
                features using visual observations. Under this final rule, landscapes
                with non-channelized, diffuse stormwater and overland sheet flow are
                excluded regardless of the flow regime characteristics, because under
                [[Page 22326]]
                these circumstances, flow is occurring only in direct response to
                precipitation over areas that meet the definition of ``upland.'' As
                explained by the Rapanos plurality, regulating these features as waters
                of the United States extends beyond the rational meaning of the term.
                547 U.S. at 734.
                 With respect to implementing the final rule's paragraph (b)(5)
                exclusion for certain ditches, the reach of a ditch that meets
                paragraph (a)(1) or (2) of the final rule is considered a water of the
                United States, with ``reach'' interpreted similarly to how it is used
                for tributaries in Section III.D of this notice (i.e., a section of a
                ditch along which similar hydrologic conditions exist, such as
                discharge, depth, area, and slope). The jurisdictional status of other
                reaches of the same ditch must be assessed based on the specific facts
                and under the terms of the final rule to determine the jurisdictional
                status of those reaches. For example, a ditch that is constructed in a
                tributary is not an excluded ditch under paragraph (b)(5) so long as it
                satisfies the flow conditions of the ``tributary'' definition or the
                conditions of the ``adjacent wetlands'' definition as further described
                in Section III.D and Section III.E. Further, the ditch exclusion does
                not affect the possible status of a ditch as a point source. Also, a
                ditch constructed in an adjacent wetland that satisfies the conditions
                of paragraph (a)(4) is not excluded. The agencies believe that the
                final rule's ditch exclusion encompasses most irrigation and drainage
                ditches, including most roadside and other transportation ditches, as
                well as most agricultural ditches.
                 In paragraph (b)(6) of this final rule, the agencies are
                reconfirming the longstanding prior converted cropland exclusion. This
                final rule also codifies the abandonment principle as applied to the
                prior converted cropland exclusion, as first articulated in the 1993
                preamble (58 FR 45033), and provides additional clarification regarding
                what constitutes ``agricultural purposes.'' As a result of this final
                rule, the change in use analysis will no longer be used to evaluate
                whether the prior converted cropland exclusion applies. Under the final
                rule, when cropland has been abandoned (i.e., the cropland has not been
                used for or in support of agricultural purposes for a period of greater
                than five years), and wetlands have returned, any prior converted
                cropland designation for that site will no longer be valid for purposes
                of the CWA.
                 The USDA is responsible for making determinations as to whether
                land is prior converted cropland for its FSA purposes, whereas the
                agencies are responsible for determining applicability of the exclusion
                for CWA purposes, consistent with the government's longstanding
                interpretation of the agencies' authority under the CWA. See 33 CFR
                328.3(a)(8) (``Notwithstanding the determination of an area's status as
                prior converted cropland by any other Federal agency, for the purposes
                of the Clean Water Act, the final authority regarding Clean Water Act
                jurisdiction remains with EPA.''); CWA Regulatory Programs, 58 FR
                45,008, 45,036 (Aug. 25, 1993); Administrative Authority to Construe
                Sec. 404 of the Federal Water Pollution Control Act (``Civiletti
                Memorandum''), 43 Op. Att'y Gen. 197 (1979). The agencies will defer to
                USDA for purposes of establishing whether a parcel or tract of land has
                received a prior converted cropland determination and is therefore
                eligible for the prior converted cropland exclusion under this rule. A
                landowner without an existing prior converted cropland determination
                may seek a new determination from the USDA.\59\ The USDA is subject to
                specific statutes designed to protect landowner privacy and, as such,
                is prohibited from making certain parcel-specific information available
                without the landowner's consent. To ensure that the agencies can rely
                on a USDA prior converted cropland determination, the landowner will
                need to either provide a copy of the determination or provide the
                agencies with a signed consent form to allow the agencies access to the
                relevant information for the limited purpose of verifying USDA's prior
                converted cropland determination. The agencies recognize that privacy
                and confidentiality issues concerning certain producer information is
                addressed at section 1619 of the Food, Conservation, and Energy Act of
                2008 (7 U.S.C. 8791(b)) and section 1244(b) of the Food Security Act of
                1985, as amended (16 U.S.C. 3844(b)). If a parcel is found to be prior
                converted cropland, as defined in this rule, it is not a water of the
                United States.
                ---------------------------------------------------------------------------
                 \59\ The agencies note that the USDA's regulatory definition of
                ``prior converted cropland'' in the FSA and the definition being
                established in this final rule have different purposes and they are
                substantively different. Based on the FSA's statutory requirements,
                the USDA definition of ``prior converted cropland'' requires that
                agricultural commodity crop production be made possible prior to
                1985. See 7 CFR 12.2(a)(8); 16 U.S.C. 3801 (defining converted
                wetland) and 16 U.S.C. 3822(b)(1)(A) (establishing the pre-1985
                exemption). If commodity crop production was made possible on a
                particular parcel or tract of land prior to 1985, that land is
                eligible for the prior converted cropland exclusion in this final
                rule. Once eligibility is determined, the agencies will evaluate the
                land to determine if the exclusion currently applies, or if the land
                has been abandoned, as described in this final rule.
                ---------------------------------------------------------------------------
                 Once a threshold determination has been made that certain lands are
                prior converted cropland, the EPA and the Corps are responsible for
                implementing the prior converted cropland exclusion for CWA purposes
                and identifying (as further explained below) whether the lands have
                been abandoned and whether wetlands conditions have returned such that
                they are no longer eligible for the prior converted cropland exclusion
                in this rule and thus may be waters of the United States. In addition
                to working closely with the USDA, the agencies will consider
                documentation from NOAA and FEMA when evaluating whether a parcel of
                land may no longer be eligible for the CWA prior converted cropland
                exclusion. In all cases, the burden to prove that such parcel is a
                water of the United States remains on the agencies. The agencies'
                implementation of the prior converted cropland exclusion for CWA
                regulatory purposes does not affect the USDA's administration of the
                FSA or a landowner's eligibility for benefits under FSA programs.\60\
                ---------------------------------------------------------------------------
                 \60\ See the Notice of Proposed Rulemaking at 84 FR 4193 for a
                summary of how the agencies historically implemented and enforced
                this exclusion.
                ---------------------------------------------------------------------------
                 Under the final rule, to determine the continuing applicability of
                the prior converted cropland exclusion, the Corps must first determine
                whether the land has been ``abandoned.'' As described previously, prior
                converted cropland will be considered abandoned if it is not used for,
                or in support of, agricultural purposes at least once in the
                immediately preceding five years. In making an abandonment
                determination, the Corps will work with the landowner and USDA, as
                appropriate, to determine whether the land is currently or has been
                used for or in support of agricultural purposes at least once in the
                immediately preceding five years. As noted above, there are many uses
                that may fall within this category, including but not limited to,
                grazing; haying; idling land for conservation purposes (e.g., habitat;
                pollinator and wildlife management; and water storage, water supply,
                and flood management); irrigation tailwater storage; crawfish farming;
                cranberry bogs; nutrient retention; and idling land for soil recovery
                following natural disasters like hurricanes and drought. Some of those
                land uses may not be obvious to Corps field staff, so the agencies may
                rely on public or private documentation to demonstrate that the land is
                enrolled in a conservation program or is otherwise
                [[Page 22327]]
                being used for or in support of agricultural purposes. Such information
                may include aerial photographs, topographical maps, cultivation maps,
                crop expense or receipt records, field- or tract-specific grain
                elevator records, and other records generated and maintained in the
                normal course of doing business, including government agency records
                documenting participation in a conservation program, and other
                documentation reasonably establishing one or more ``agricultural
                purposes.''
                 The final rule requires that the land be used for or in support of
                agricultural purposes within the immediately preceding five years. In
                implementing this requirement, the agencies will consider documentation
                from USDA, NOAA, FEMA, and other Federal and State agencies to
                determine whether the land was used for or in support of agricultural
                purposes in the immediately preceding five years. For example, USDA
                administers multiple programs that track whether fields have been
                planted or harvested in the normal course, or enrolled in long-term
                conservation rotations, and the agency provides crop insurance for
                years where those activities were halted for reasons covered under
                their insurance policies; NOAA tracks long- and short-term weather
                patterns and can provide information and data concerning flood or
                drought conditions that may cause or contribute to idling land in
                support of agricultural purposes; and FEMA administers emergency
                response programs for natural disasters, including hurricanes,
                wildfires, and other events that could also require idling land for
                soil recovery and other agricultural purposes. The agencies will take
                into account this information, and additional documentation reasonably
                establishing ``agricultural purposes'' when evaluating whether cropland
                has been used for or in support of agricultural purposes in the
                immediately preceding five years.
                 If the Corps determines that the land is abandoned, then it must
                evaluate the current condition of the land to determine whether wetland
                conditions have returned. If wetlands are currently present on the
                property, the agencies will determine whether the wetlands are
                ``adjacent wetlands'' and therefore ``waters of the United States,''
                consistent with this final rule. As the term ``prior converted
                cropland'' suggests, and as stated in the preamble to the 1993 Rule,
                land properly designated as prior converted cropland has typically been
                so extensively modified from its prior condition that it no longer
                exhibits wetland hydrology or vegetation, and no longer performs the
                functions it did in its natural and original condition as a wetland. 58
                FR 45032. It is often altered and degraded, with long-term physical and
                hydrological modifications that substantially reduce the likelihood of
                reestablishment of hydrophytic vegetation. Consistent with longstanding
                agency policy and wetland delineation procedures, if a former wetland
                has been lawfully manipulated to the extent that it no longer exhibits
                wetland characteristics under normal circumstances, it would not be
                jurisdictional under the CWA. The altered nature of prior converted
                cropland and its conditions constitute the ``normal circumstances'' of
                such areas. The agencies expect the majority of prior converted
                cropland in the nation to fall into this category and not to be subject
                to CWA regulation, even after it is abandoned. However, at least some
                abandoned prior converted cropland may, under normal circumstances,
                meet the definition of ``wetlands'' under paragraph (c)(16).
                 In paragraph (b)(7), the agencies clarify their longstanding view
                that the artificial irrigation exclusion applies only to the specific
                land being artificially irrigated, including fields flooded for
                agricultural production, including but not limited to rice or cranberry
                growing, which would revert to upland should artificial irrigation
                cease. Historically, the agencies have taken the position that ponds
                for rice growing are generally not considered waters of the United
                States, as reflected in the 1986 and 1988 preambles. See 51 FR 41206,
                41217 (November 13, 1986) and 53 FR 20764-65 (June 6, 1988). In the
                past, the agencies have considered those under the artificial lakes or
                ponds category of waters that are generally non-jurisdictional, but
                this final rule includes them in the artificial irrigation exclusion
                category as any wetland crop species, such as rice and cranberry
                operations, that is typically supplied with artificial flow irrigation
                or similar mechanisms.
                 A number of commenters addressed the difficulty in proving that
                land would revert to upland when irrigation ceased and suggested
                clarification as to whether documentation was needed as proof. The
                agencies agree that proving that land would revert to upland may be
                challenging in some circumstances. The agencies have developed
                strategies and guidance to assist with determining if wetland
                conditions will persist when irrigation ceases. This includes, but is
                not limited to, utilizing aerial photography, soil maps, LiDAR, remote
                sensing, and field assessments to determine if wetland conditions are
                the result of irrigation or are naturally occurring.
                 Commenters also raised concern about whether the exclusion is only
                available for rice and cranberry growing areas. The inclusion of rice
                and cranberries in the proposed rule were simply examples and not
                intended to be exhaustive. In this final rule, the agencies conclude
                that it is not necessary to list all crops potentially eligible for the
                exclusion, and therefore simply reference ``agricultural production.''
                The relevant factor in determining the application of the exclusion is
                not what type of crop may be planted or cultivated, but whether the
                area is artificially irrigated and would revert to upland should
                irrigation cease.
                 Under the final rule, the exclusion for waters meeting the
                conditions of paragraph (b)(8) applies to artificial lakes and ponds
                created through construction or excavation in upland or in non-
                jurisdictional features. Such artificial lakes and ponds would not be
                jurisdictional under the final rule even if they maintain a hydrologic
                surface connection to waters of the United States or are inundated by
                waters of the United States. Conveyances created in upland that are
                physically connected to and are a part of the excluded feature also are
                excluded.
                 A commenter inquired as to whether the artificial waterbody created
                by impounding a jurisdictional tributary would be jurisdictional. The
                agencies note that under the final rule, impoundments are considered
                jurisdictional if they impound a paragraph (a)(1) through (4) water,
                which includes jurisdictional tributaries, and contribute surface water
                flow in a typical year to a paragraph (a)(1) water or are inundated by
                flooding from a paragraph (a)(1) through (3) water in a typical year.
                Impounding a jurisdictional tributary does not create a non-
                jurisdictional lake or pond that would be excluded under paragraph
                (b)(8), but rather creates a jurisdictional impoundment so long as it
                meets the conditions of paragraph (a)(3) as defined in paragraph
                (c)(6). The agencies note that artificial lakes and ponds that are
                excluded from the definition of ``waters of the United States'' could,
                in some circumstances, be point sources of pollutants subject to
                sections 301 and 402 of the Act.
                 Under paragraph (b)(9), water-filled depressions constructed or
                excavated in upland or in non-jurisdictional waters that are incidental
                to mining or construction activity, and pits excavated in upland or in
                non-jurisdictional waters for the purpose of obtaining fill,
                [[Page 22328]]
                sand, or gravel are excluded from the definition of ``waters of the
                United States.'' To determine whether a water or feature meets this
                exclusion, the agencies will evaluate whether the water feature is
                constructed or excavated in upland or in non-jurisdictional waters as
                part of these industrial activities. In addition, such water-filled
                depressions and pits could become waters of the United States once
                construction or mining activities have permanently ceased and the
                depressions or pits meet the conditions of a paragraph (a)(1) through
                (4) water.
                 The final rule excludes in paragraph (b)(10) stormwater control
                features constructed or excavated in upland or in non-jurisdictional
                waters to convey, treat, infiltrate, or store stormwater run-off. As
                stated previously, the rule excludes a diverse range of stormwater
                control features that are currently in place and that may be developed
                in the future. To determine if such a water or feature meets the
                exclusion, the agencies will evaluate whether the stormwater feature is
                constructed or excavated in upland or in non-jurisdictional waters.
                 Paragraph (b)(11) of the final rule clarifies that groundwater
                recharge, water reuse, and wastewater recycling structures constructed
                or excavated in upland or in non-jurisdictional waters are excluded. To
                determine whether a such a structure meets this exclusion, the agencies
                will evaluate whether the water or feature is constructed or excavated
                in upland or in non-jurisdictional waters. This exclusion includes
                detention and retention basins as well as groundwater recharge basins
                and infiltration ponds excavated in upland or in non-jurisdictional
                waters for wastewater recycling. The exclusion also covers water
                distributary structures that are built in upland or in non-
                jurisdictional waters for water recycling. These features often connect
                or carry surface water flow to other water recycling structures, for
                example, a channel or ditch that carries water to an infiltration pond.
                Consistent with longstanding practice, the agencies do not consider
                these water distributary systems jurisdictional.
                 As discussed previously, the agencies are not changing the
                longstanding approach to implementing the waste treatment system
                exclusion. As a result, the agencies will continue to apply the
                exclusion to systems that are treating water to meet the requirements
                of the CWA. Discharges from these systems to waters of the United
                States would continue to be subject to regulation by the CWA section
                402 permitting program. Similarly, if a waste treatment system is
                abandoned or otherwise ceases to serve the treatment function for which
                it was designed, it does not continue to qualify for the exclusion.
                 Some commenters suggested the agencies clarify the way in which the
                waste treatment system exclusion is currently implemented. Many
                comments inquired as to whether stormwater systems and wastewater reuse
                facilities are considered part of a complete waste treatment system for
                purposes of the waste treatment system exclusion. To enhance clarity,
                the agencies have provided in the final rule two related exclusions in
                paragraphs (b)(10) and (b)(11) and have added settling basins and
                cooling ponds to the definition of ``waste treatment system'' in
                paragraph (c)(15). The agencies note that cooling ponds that are
                created under CWA section 404 in jurisdictional waters and that have
                CWA section 402 permits are subject to the waste treatment system
                exclusion under the 2019 Rule and will also be excluded under the final
                rule. Cooling ponds created to serve as part of a cooling water system
                with a valid State or Federal permit constructed in waters of the
                United States prior to enactment of the 1972 amendments of the CWA and
                excluded from jurisdiction under the 2019 Rule also remain excluded
                under the final rule. Some commenters on the proposed rule's waste
                treatment system exclusion expressed confusion regarding whether
                stormwater treatment features would be excluded under the exclusion for
                stormwater control features or under the waste treatment exclusion.
                Such determinations will depend on the specific attributes of the
                control and the water feature and thus need to be made on a case-by-
                case basis. It is possible that a stormwater feature could qualify for
                both the stormwater control features exclusion and the waste treatment
                systems exclusion. This same principle applies to other exclusions that
                may have similar cross-over features, like certain ditches used in
                stormwater management systems.
                 It is important to reiterate that while the waters and features
                listed in the final rule's exclusions are not waters of the United
                States, some of them may convey surface water flow to a downstream
                jurisdictional water, so that reaches of a water upstream and
                downstream of the excluded water or feature may meet the definition of
                ``tributary'' in paragraph (c)(12). For example, when some water from a
                tributary is moved into a downstream jurisdictional water through an
                excluded ditch, the ditch itself is excluded from jurisdiction under
                the final rule but the tributary upstream of the ditch is
                jurisdictional if the non-jurisdictional ditch conveys surface water
                flow in a typical year to the downstream jurisdictional reach.
                I. Placement of the Definition of ``Waters of the United States'' in
                the Code of Federal Regulations
                1. What are the agencies finalizing?
                 The definition of ``waters of the United States'' has historically
                been placed in eleven locations in the Code of Federal Regulations
                (CFR). For the sake of simplicity, in this final rule, the agencies are
                codifying the definition of ``waters of the United States'' in only two
                places in the CFR--once in Title 33 (which implements the Corps'
                statutory authority) and once in Title 40 (which generally implements
                the EPA's statutory authority).
                2. Summary of Final Rule Rationale and Public Comment
                 The agencies proposed to maintain the definition of ``waters of the
                United States'' at 33 CFR 328 and in ten locations in Title 40. The
                agencies solicited comment on an alternative approach under which the
                definition would be codified in just two locations within the CFR,
                rather than in the eleven locations in which it has previously
                appeared. Most commenters recommended that the definition of ``waters
                of the United States'' be codified twice, once in Title 33 of the CFR
                and once in Title 40 of the CFR. These commenters recommended limiting
                codification to two locations in order to clarify that there is a
                single definition of ``waters of the United States'' applicable to the
                entire CWA, to reduce confusion and conflicting interpretations under
                different programs, and to promote ease of use for the regulated
                community and for laypersons. Many of these commenters suggested
                including a cross-reference in the original ten locations of Title 40
                of the CFR. Some commenters recommended continuing the agencies'
                practice of codifying the definition of ``waters of the United States''
                in eleven locations within the CFR.
                 The agencies agree with commenters that stated that codifying the
                definition of ``waters of the United States'' in two locations within
                the CFR will reduce confusion and promote ease of use for States,
                Tribes, local government, the regulated community, and the general
                public. With this final rule, the agencies are codifying the definition
                of ``waters of the United States'' in Title 33 of the CFR, which
                implements the Corps' statutory authority, at 33 CFR 328.3, and in
                Title 40, which generally implements
                [[Page 22329]]
                the EPA's statutory authority, at 40 CFR 120.2. In the sections of the
                CFR where the EPA's regulatory definition previously existed, 40 CFR
                110.1, 112.2, 116.3, 117.1, 122.2, 230.3, 232.2, 300.5, 302.3, 401.11,
                and Appendix E to 40 CFR part 300, this final rule cross-references the
                newly created section of the regulations containing the definition of
                ``waters of the United States.'' The agencies have placed the EPA's
                definition of ``waters of the United States'' in a previously
                unassigned part of 40 CFR. The change in placement has no implications
                on CWA program implementation; it is made for the sole purpose of
                enhancing the clarity of the federal regulations. Placing the
                definition of ``waters of the United States'' in a single section in
                the part of the regulations that implements the EPA's authority and
                once again in the part of the regulations that implements the Corps'
                authority makes clearer to members of the public that there is a single
                definition of ``waters of the United States'' applicable to the CWA and
                its implementing regulations.
                IV. State, Tribal, and Federal Agency Datasets of Waters of the United
                States
                 During the extensive pre-proposal outreach to the general public
                and focused engagement with States and Tribes, the agencies heard from
                a number of States about their familiarity with waters within their
                borders and their expertise in aquatic resource mapping. As co-
                implementers of CWA programs, they also emphasized the potential
                benefit of greater State and tribal involvement in jurisdictional
                determinations. For these reasons, several States suggested that the
                agencies consider their knowledge and increase the role of States and
                Tribes in identifying those waters that are waters of the United
                States. Stakeholders also indicated that maps could increase certainty
                and transparency regarding the data and methods used to determine which
                waters are jurisdictional and which waters are not.
                 In the Notice of Proposed Rulemaking for this rule, the agencies
                solicited comment as to how to create a regulatory framework that would
                authorize interested States, Tribes, and other Federal agencies to
                develop for the agencies' approval geospatial datasets representing
                waters of the United States, as well as waters excluded from the
                definition, ``waters of the State'' or ``waters of the Tribe'' within
                their respective borders. 84 FR 4154, 4198-4200 (February 14, 2019).
                This concept was not part of the proposed regulatory text; the agencies
                utilized the notice to solicit input and suggestions from the regulated
                public, States, Tribes, and other stakeholders.
                 Some commenters raised concerns regarding the limitations of data
                currently available for creating geospatial datasets of jurisdictional
                waters, particularly commenting on the limitations of national datasets
                such as the National Hydrography Dataset (NHD) and the National
                Wetlands Inventory (NWI). Some commenters expressed concerns about the
                resolution, completeness, accuracy, and usefulness of publicly-
                available data, with some stating that geospatial datasets cannot
                accurately assess the details needed to remotely determine or delineate
                jurisdictional waters. Other commenters noted that, despite the
                limitations in the available data, the agencies should attempt to
                quantify changes in the jurisdictional status of specific waterbody
                categories as a result of the final rule.
                 The agencies agree that there are significant limitations to the
                extent to which currently available data can be used to identify the
                scope of all or even a subset of jurisdictional waters. There are
                currently no comprehensive datasets through which the agencies can
                depict the universe of federally-regulated waters under the CWA. For
                example, the agencies attempted to use the NHD at high resolution and
                NWI to assess the potential change in CWA jurisdiction as a result of
                the proposed rule to revise the definition of ``waters of the United
                States,'' but ultimately concluded that the limitations of these
                datasets precluded their use for quantifying the extent of waters whose
                jurisdictional status could change under the proposed rule, as
                discussed in Section V and in the Resource and Programmatic Assessment
                for the final rule. Due to these limitations, which were confirmed
                during the public comment period for the proposed rule and an
                evaluation by the agencies, the agencies also did not use the NHD or
                NWI to assess potential changes in jurisdiction as a result of the
                final rule.
                 While the NHD and NWI are the most comprehensive hydrogeographic
                datasets mapping waters and wetlands in the United States and are
                useful resources for a variety of Federal programs, including CWA
                programs, they currently have technical limitations that present
                significant challenges for use as standalone tools to determine the
                full scope of CWA jurisdiction and for creating geospatial datasets of
                jurisdictional waters, regardless of the regulatory definition of
                ``waters of the United States.'' Importantly, the NHD and NWI were not
                created for regulatory purposes, so their limitations as comparative
                tools for CWA jurisdiction are not surprising.
                 Due in part to the resolution of the data, limitations of the NHD
                for purposes of accurately mapping the scope of jurisdictional waters
                under the CWA include errors of omission (e.g., failure to map streams
                that exist on the ground); errors of commission (e.g., mapping streams
                that do not exist on the ground); horizontal positional inaccuracies;
                misclassification of stream flow condition, particularly in headwaters;
                and inconsistent mapping in different parts of the country. The NWI
                presents similar challenges for identifying federally-regulated waters,
                including the foundational obstacle of having a ``wetlands'' definition
                that differs from the federal regulatory ``wetlands'' definition. The
                NWI also contains errors of omission (e.g., failure to map wetlands
                that exist on the ground), errors of commission (e.g., mapping wetlands
                that do not exist on the ground), and potentially inaccurate wetland
                boundary identification. The limitations identified herein are examples
                and do not represent an exhaustive list of challenges faced by the
                agencies in potentially using them to identify the scope of CWA
                jurisdiction. For a more detailed discussion of the NHD and NWI
                datasets and their limitations for use as standalone tools to determine
                the full scope of waters that are and are not waters of the United
                States, see Chapter II of the Resource and Programmatic Assessment
                supporting this final rule.
                 It has been the consistent position of the agencies that the NHD
                and the NWI do not represent the scope of waters subject to CWA
                jurisdiction.\61\ Indeed,
                [[Page 22330]]
                as part of the 2015 rulemaking, the agencies stated that they ``do not
                have maps depicting waters of the United States under either present
                regulatory standards or those in the final [2015] rule.'' \62\ This
                remains true today; the agencies do not have maps of waters of the
                United States under the 2015 Rule, under the 2019 Rule, or under this
                final rule. For this reason, and to provide the public and the agencies
                with more information on which waters are or are not waters of the
                United States, the agencies sought public comment on a possible
                framework for developing geospatial datasets.
                ---------------------------------------------------------------------------
                 \61\ See, e.g., Letter from Nancy Stoner, Acting Assistant
                Adm'r, EPA Office of Water, to Lamar Smith, Chairman, Comm. on
                Science, Space, and Tech., U.S. House of Representatives (July 28,
                2014) (emphasis added), available at https://web.archive.org/web/20180919173837/https://science.house.gov/sites/republicans.science.house.gov/files/documents/epa_releases_maps_letter.pdf. (``[N]o national or statewide maps
                have been prepared by any agency, including EPA, showing the scope
                of waters subject to the Clean Water Act. . . . To develop maps of
                jurisdictional waters requires site-specific knowledge of the
                physical features of water bodies, and these data are not
                available[.]'') (emphasis added); see also Letter from Nancy Stoner,
                Deputy Assistant Adm'r, EPA Office of Water, to Lamar Smith,
                Chairman, Comm. on Science, Space, and Tech., U.S. House of
                Representatives (August 6, 2014), available at https://web.archive.org/web/20180919173837/https://science.house.gov/sites/republicans.science.house.gov/files/documents/epa_releases_maps_letter.pdf); U.S. EPA, Mapping the Truth, The EPA
                Blog (Aug. 28, 2014), available at https://blog.epa.gov/2014/08/28/mapping-the-truth/ (``While these [U.S. Geological Survey and Fish &
                Wildlife Service] maps are useful tools for water resource managers,
                they cannot be used to determine Clean Water Act jurisdiction--now
                or ever.''); Letter from Kenneth J. Kopocis, Deputy Assistant Adm'r,
                EPA Office of Water, to Lamar Smith, Chairman, Comm. on Science,
                Space, and Tech., U.S. House of Representatives (Jan. 8, 2015)
                (``These [USGS] maps were not prepared for the purpose of, nor do
                they represent, a depiction of the scope of waters protected under
                the Clean Water Act.''); Impact of the Proposed ``Waters of the
                United States''' Rule on State and Local Governments Before the H.
                Comm. on Transp. & Infrastructure and the S. Comm. on Env't & Pub.
                Works, 114th Cong. (2015)(testimony of Gina McCarthy, Adm'r,
                EPA)(stating that the NHD and NWI maps were ``not used to determine
                jurisdiction and not intended to be used for jurisdiction,'' ``are
                not relevant to the jurisdiction of the `waters of the U.S.',''
                ``are not consistent with how we look at the jurisdiction of the
                Clean Water Act,'' and have ``nothing to do, as far as I know, with
                any decision concerning jurisdiction of the Clean Water Act'').
                 \62\ See Response to Comments for the Clean Water Rule, Clean
                Water Rule Comment Compendium Topic 8: Tributaries, Docket ID. No.
                EPA-HQ-OW-2011-0880-20872, p. 442, https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-20872.
                ---------------------------------------------------------------------------
                 The agencies acknowledge that they have previously taken the
                position that ``maps of all the jurisdictional or non-jurisdictional
                waters are not feasible,'' \63\ and that maps ``cannot be used to
                determine Clean Water Act jurisdiction--now or ever,'' see U.S. EPA,
                Mapping the Truth, The EPA Blog (August 28, 2014). Rather than
                declaring the task too difficult, the agencies have decided to initiate
                development of state-of-the-art geospatial data tools through Federal,
                State, and tribal partnerships to provide an enhanced, publicly-
                accessible platform for critical CWA information, such as the location
                of federally jurisdictional waters, the applicability of State and
                tribal water quality standards, permitted facility locations, impaired
                waters, and other significant features. Such mapped features would make
                it easier for agency field staff, the general public, property owners,
                permit-holders and others to understand the relationship between
                familiar geographical features and the overlay of CWA jurisdictional
                waters. For Federal, State, and tribal agencies, such geospatial
                datasets could improve the administration of CWA programs and
                attainment of water quality goals. Geospatial datasets and resulting
                future maps that indicate waters likely subject to federal jurisdiction
                could allow members of the regulated community to more easily and
                quickly ascertain whether they may want to contact a government agency
                regarding the potential need for a CWA permit. These datasets, when
                fully developed, would promote greater regulatory certainty, relieve
                some of the regulatory burden associated with determining the need for
                a permit, and play an important part in helping to attain the goals of
                the CWA. In the future, the agencies and States could use geospatial
                datasets to identify waters with applicable water quality standards,
                total maximum daily loads, water quality monitoring data, and other
                beneficial information in one layered geospatial map.
                ---------------------------------------------------------------------------
                 \63\ Id. at p. 593.
                ---------------------------------------------------------------------------
                 Since the proposed rule was published, the agencies have been
                engaging with other Federal agencies to discuss existing geospatial
                datasets and discuss opportunities to build upon them to map the
                nation's aquatic resources, including both waters of the United States
                and non-jurisdictional waters. To align the agencies' waters of the
                United States mapping interests with the U.S. Department of Interior's
                (DOI) established and ever-improving aquatic resource mapping efforts,
                including the NHD, NWI, and other datasets, the EPA and the Corps are
                engaging with the U.S. Geological Survey (USGS) and the U.S. Fish and
                Wildlife Service (FWS) and have established a technical working group
                to develop strategies that can address their CWA mapping needs.\64\ The
                agencies believe the most efficient way to address their regulatory
                needs is to better align their efforts with DOI's existing processes
                and national mapping capabilities. The EPA, USGS, and FWS have a long
                history of working together to map the nation's aquatic resources. As
                the agencies pursue this mapping effort, they will continue to
                collaborate with DOI to enhance the NHD, NWI, and other products to
                better map the nation's water resources and the waters of the United
                States while enhancing their utility to other CWA programs that the EPA
                and the Corps implement.
                ---------------------------------------------------------------------------
                 \64\ See Letter from David Ross, Asst. Adm'r, EPA Office of
                Water, and Ryan Fisher, Principal Deputy Asst. Sec. of the Army
                (Civil Works), U.S. Army, to Dr. Tim Petty, Asst. Sec. for Water and
                Science, U.S. DOI, and Rob Wallace, Asst. Sec. for Fish, Wildlife,
                and Parks, U.S. DOI (September 17, 2019); see also Letter from Dr.
                Jim Reilly, Director, U.S. Geological Survey, to David Ross, Asst.
                Adm'r, EPA Office of Water, and Ryan Fisher, Principal Deputy Asst.
                Sec. of the Army (Civil Works), U.S. Army (October 1, 2019); see
                also Letter from Gary Frazer, Asst. Dir. for Ecological Services,
                U.S. Fish and Wildlife Service to David Ross, Asst. Adm'r, EPA
                Office of Water, and Ryan Fisher, Principal Deputy Asst. Sec. of the
                Army (Civil Works), U.S. Army (December 4, 2019).
                ---------------------------------------------------------------------------
                 In addition, the EPA's Office of Research and Development (ORD) has
                established an ``Improved Aquatic Resource Mapping'' research area,
                which will be implemented in coordination with the Corps and EPA's
                Office of Water. This research area could build upon longstanding EPA
                aquatic resource research and leverage existing research partnerships
                with other Federal agencies, States, and Tribes to improve mapping of
                aquatic resources. This research effort is intended to support the
                agencies' need for improved data to inform CWA jurisdictional
                determinations, to support other regulatory and non-regulatory needs,
                and to contribute to ongoing and new EPA research. In the long-term,
                the agencies anticipate that this effort will yield improved methods of
                verifying aquatic resources to support CWA jurisdictional
                determinations and other programmatic needs. In the short-term, ORD
                intends to produce three primary products to begin to advance this
                goal: A review of the existing aquatic resource mapping methodologies,
                development of novel geospatial datasets in select watersheds, and
                development of calibration and validation datasets. All three products
                can incorporate outreach efforts to communicate and transfer results to
                stakeholders.
                 The agencies also believe that any future efforts they pursue to
                work with States, Tribes, and Federal agencies to create geospatial
                datasets of jurisdictional waters will improve the data and information
                that is available to the public about the jurisdictional scope of the
                CWA, recognizing that data limitations may always exist. Many
                commenters supported the development of geospatial datasets or a
                mapping system of waters of the United States to provide a clear
                understanding of the presence or absence of jurisdictional waters. Many
                such commenters provided caveats and anticipated challenges. Other
                commenters suggested that creating such datasets posed too many
                challenges to be worthwhile. Many of these commenters considered the
                development of geospatial datasets of jurisdictional waters to be
                infeasible or inappropriate based on the need for field verification
                and maintenance to keep the datasets up-to-date, and the concern that
                potentially incomplete lists could be inaccurately perceived as a
                definitive list of all waters of the United States. These commenters
                stated that any datasets established should be used
                [[Page 22331]]
                only as a planning tool to inform jurisdictional determinations or to
                provide guidance on the location of potential waters of the United
                States.
                 The agencies solicited comment on potential approaches to
                establishing a framework to allow States, Tribes, or Federal agencies
                to create geospatial datasets of jurisdictional waters. Some commenters
                supported deferring this effort to a future rulemaking. Several
                commenters recommended using existing technology to prioritize mapping
                traditional navigable waters prior to attempting to map jurisdictional
                tributaries or wetlands. A few commenters suggested engaging in several
                pilot projects or a phased approach before rolling out a dataset
                nationwide. Some commenters suggested that data in the geospatial
                datasets should either expire or be updated every five years, to
                reflect the timeframe for approved jurisdictional determinations or to
                ensure that the datasets effectively represent current conditions.
                 The agencies solicited comment on appropriate features and
                attributes of the website that would publish this information, as well
                as any privacy considerations the agencies should understand. A few
                commenters opposed making public the details of jurisdictional
                determinations or expressed privacy concerns regarding the creation of
                geospatial datasets of jurisdictional waters. Some commenters stated
                that jurisdictional determinations or geospatial datasets of
                jurisdictional waters should be made available to the public.
                 As the agencies work to pursue improved geospatial mapping of
                waters in the future, they intend to also work to enhance information
                that is already available to the public on jurisdictional
                determinations. The Corps maintains a website at https://permits.ops.usace.army.mil/orm-public that presents information on the
                Corps' approved jurisdictional determinations and CWA section 404
                permit decisions. Similarly, the EPA maintains a website at https://watersgeo.epa.gov/cwa/CWA-JDs/ that presents information on approved
                jurisdictional determinations made by the Corps and the EPA under the
                CWA since August 28, 2015. These websites will incorporate approved
                jurisdictional determinations made under the revised definition of
                ``waters of the United States'' that the agencies are finalizing in
                this notice.
                 In the Notice of Proposed Rulemaking, the agencies expressed
                interest in learning about experiences States, Tribes, and other
                Federal agencies have had with mapping aquatic resources and using this
                information for program implementation. A few State and tribal
                commenters expressed interest in working as partners with the agencies
                on mapping jurisdictional waters. Some State and local governments
                offered to share existing geospatial data with the agencies. Other
                State commenters were less supportive of an effort to map
                jurisdictional waters, with some raising concerns about the regulatory
                implications of mapping based on experiences in their States. Several
                State commenters raised concerns about costs of a mapping effort, with
                some commenters pointing to their own costly past mapping efforts. One
                commenter cited a State study that found that the State's best attempt
                at mapping wetlands was only 56 percent successful at classifying
                wetlands compared to field delineations. The agencies will consider the
                comments and concerns raised and coordinate closely with States,
                Tribes, and other Federal agencies in future efforts to develop
                geospatial datasets. The agencies do not anticipate developing a
                regulatory framework for geospatial datasets that would impose
                requirements on States and Tribes to develop geospatial datasets of
                jurisdictional waters; the option would simply be available for
                interested States and Tribes.
                 The agencies believe that pursuing the development of geospatial
                datasets of waters of the United States could provide for greater
                regulatory certainty and provide important information to States,
                Tribes, the regulated community, and the public. The agencies are in
                the early stages of this effort, and they will be informed by public
                comments and suggestions received in response to this rulemaking as
                they move forward.
                V. Overview of the Effects of the Rule and Supporting Analyses
                 This section provides an overview of the potential effects of the
                final rule on federal and state regulatory programs and potential
                economic impacts of the final rule. Additional detail on these analyses
                are contained in and described more fully in the Resource and
                Programmatic Assessment for the Navigable Waters Protection Rule:
                Definition of ``Waters of the United States'' and in the Economic
                Analysis for the Navigable Waters Protection Rule: Definition of
                ``Waters of the United States.'' Copies of these documents are
                available in the docket for this action.
                 In defining the term ``waters of the United States'' under the CWA,
                Congress gave the agencies discretion to articulate reasonable limits
                on the meaning of that term, confined of course by the statutory text
                and Supreme Court guidance recognizing the outer limits of the
                agencies' authorities. See, e.g., Rapanos, 547 U.S. at 758 (Roberts,
                C.J., concurring) (``Given the broad, somewhat ambiguous, but
                nonetheless clearly limiting terms Congress employed in the Clean Water
                Act, the Corps and the EPA would have enjoyed plenty of room to operate
                in developing some notion of an outer bound to the reach of their
                authority.'') (emphasis in original). With this action, the agencies
                are finalizing a new definition of ``waters of the United States.''
                 As discussed in Section II.E, the agencies conclude that this final
                rule clearly establishes the scope of jurisdictional waters under the
                CWA consistent with the legislative history and text of the statute and
                Supreme Court case law and provides greater regulatory predictability
                than the 2019 Rule regulatory text as interpreted by the Supreme Court
                and implemented through agency guidance. This final rule replaces the
                2019 Rule.
                 With respect to the CWA section 404 permitting program for the
                discharge of dredged and fill material, the agencies recognize that
                this final rule could affect approved jurisdictional determinations
                (AJDs) issued before the 2015 Rule or in States where the 2015 Rule was
                not in effect due to litigation, under the 2015 Rule, or under the 2019
                Rule. An AJD is a document issued by the Corps stating the presence or
                absence of waters of the United States on a parcel. See 33 CFR 331.2.
                As a matter of policy, AJDs are valid for a period of five years from
                the date of issuance unless new information warrants revision before
                the expiration date or a District Engineer identifies specific
                geographic areas with rapidly changing environmental conditions that
                merit re-verification on a more frequent basis. See U.S. Army Corps of
                Engineers, Regulatory Guidance Letter No. 05-02, Sec. 1(a), p. 1 (June
                2005) (RGL 05-02). The possessor of a valid AJD may request that the
                Corps reassess a parcel and grant a new AJD before the five-year
                expiration date. An AJD constitutes a final agency action pursuant to
                the agencies' definition of ``waters of the United States'' at the time
                of its issuance. See Hawkes, 136 S. Ct. at 1814. This final rule does
                not invalidate an AJD that was issued before the 2015 Rule or in States
                where the 2015 Rule was not in effect due to litigation, under the 2015
                Rule, or under the 2019 Rule. As such, these AJDs will remain valid
                until the expiration date unless one of the criteria for revision is
                met under RGL 05-02, or the recipient
                [[Page 22332]]
                of such an AJD requests that a new AJD be issued pursuant to this final
                rule.
                 Preliminary jurisdictional determinations (PJDs) issued by the
                Corps, however, are merely advisory in nature, make no legally binding
                determination of jurisdiction, and have no expiration date. See 33 CFR
                331.2; see also U.S. Army Corps of Engineers, Regulatory Guidance
                Letter No. 16-01 (October 2005). PJDs do not definitively state whether
                waters of the United States are present on a parcel. See Hawkes, 136 S.
                Ct. at 1812. However, as with AJDs, a recipient of a PJD may request a
                new PJD or an AJD be issued under this final rule.
                 This final rule should not significantly affect the scope of waters
                over which the Corps retains permitting authority in States that have
                assumed the CWA section 404 dredged or fill material permit program
                pursuant to section 404(g), or the waters over which the Corps would
                retain permitting authority should States and Tribes assume the program
                in the future. When States or Tribes assume administration of the
                section 404 program, the Corps retains administration of permits in
                certain waters. 33 U.S.C. 1344(g). The scope of CWA jurisdiction as
                defined by ``waters of the United States'' is distinct from the scope
                of waters over which the Corps retains authority following State or
                tribal assumption. The Corps-retained waters are identified during
                approval of a State or tribal section 404 program, and any
                modifications are approved through a formal EPA process. 40 CFR 233.36.
                The way in which the Corps identifies waters to be retained was most
                recently addressed on July 30, 2018, in a memorandum from R.D. James,
                Assistant Secretary of the Army (Civil Works).\65\ The EPA also intends
                to clarify the issue in a separate ongoing rulemaking process designed
                to facilitate State and tribal assumption of the section 404 program.
                The scope of waters assumed by States or Tribes that are granted
                permitting authority under section 404(g) is dependent on the
                definition of ``waters of the United States,'' and will change with
                this final rule. For the States that already have section 404 programs
                (Michigan and New Jersey), those States have corresponding State
                wetland permitting programs that may apply in State waters that will no
                longer be jurisdictional under the final rule.
                ---------------------------------------------------------------------------
                 \65\ The memorandum is available at https://www.army.mil/e2/c/downloads/525981.pdf.
                ---------------------------------------------------------------------------
                 For the proposed rule, the agencies conducted a series of analyses
                to better understand the potential effects across CWA programs
                associated with a revised definition of ``waters of the United
                States.'' The agencies solicited comment on all aspects of the analyses
                performed and published in support of the proposed rule, including the
                assumptions made, information used, and the three case studies
                presented in the economic analysis. The agencies further requested that
                commenters provide any data that could assist the agencies in
                evaluating and characterizing potential effects of the proposed rule.
                The agencies have incorporated additional information on tribal
                programs, updated the aquatic resource analysis, and have made other
                changes, particularly in light of the final rule repealing the 2015
                Rule and recodifying the pre-existing regulations (the 2019 Rule). The
                2019 Rule was finalized between the proposed and final rulemaking
                phases of this rule and changed the baseline for the analyses and
                discussion of potential effects on aquatic resources, CWA programs, and
                costs. The agencies note that the final rule is not based on the
                information in the agencies' economic analysis or resource and
                programmatic assessment. See, e.g., NAHB, 682 F.3d at 1039-40. This
                information was not used to establish the new regulatory text for the
                definition of ``waters of the United States.''
                 As discussed in Section IV and in the proposed rule preamble (84 FR
                4200), the agencies are not aware of any map or dataset that accurately
                or with any precision portrays the scope of CWA jurisdiction at any
                point in the history of this complex regulatory program. Establishing a
                mapped baseline from which to assess regulatory changes is likewise
                impracticable at this time, just as it was when the agencies finalized
                the 2015 Rule.\66\ The challenge of identifying an accurate baseline is
                further complicated by a long history of an evolving definition of
                ``waters of the United States.'' As summarized in Section II, what was
                understood about the potential scope of CWA jurisdiction changed in the
                1970s following National Resources Defense Council, Inc. v. Callaway,
                392 F. Supp. 685 (D.D.C. 1975), in the mid-1980s with Riverside Bayview
                and regulatory updates, in 2001 with the landmark SWANCC decision, in
                2006 with the fractured Rapanos decision, in 2007 and 2008 with the
                agencies' attempts to discern the meaning of the Rapanos decision
                through guidance and throughout the ensuing decade of litigation that
                tested those interpretations, in 2015 with a major rulemaking to
                redefine the operative phrase ``waters of the United States'' and
                throughout the complex litigation following that rulemaking, and in
                2019 with a rule to repeal the 2015 Rule and recodify pre-existing
                regulations. As the Chief Justice of the Supreme Court succinctly
                observed in 2016, ``[i]t is often difficult to determine whether a
                particular piece of property contains waters of the United States . . .
                .'' Army Corps of Eng'rs v. Hawkes Co., 136 S. Ct. at 1812. Given the
                complicated history of ``waters of the United States,'' the agencies
                are not aware of any means to quantify changes in CWA jurisdiction with
                any precision that may or may not occur as a result of this final rule.
                ---------------------------------------------------------------------------
                 \66\ See U.S. EPA and Department of the Army, Response to
                Comments of the EPA-Army Clean Water Rule at Topic 8: Tributaries p.
                442 (May 20, 2015) (``2015 Rule RTC'') (Docket ID: EPA-HQ-OW-2011-
                0880-20872), available at https://www.regulations.gov/document?D=EPA-HQ-OW-2011-0880-20872.(``The agencies do not have
                maps depicting waters of the United States under either present
                regulatory standards or those in the final rule.''); see also id. at
                593 (`[M]aps of all the jurisdictional or non-jurisdictional waters
                are not feasible[.]'').
                ---------------------------------------------------------------------------
                 The agencies acknowledge that they faced criticism from many
                commenters regarding the accuracy and assumptions they made when
                attempting to estimate changes in jurisdiction for the 2015 Rule's
                economic analysis (EA), which was then utilized for a portion of the
                proposed rule EA and the 2019 Rule EA. For the 2015 Rule EA, the
                agencies reviewed Corps approved jurisdictional determinations made
                under pre-2015 Rule practice to evaluate how the jurisdictional status
                of those waters might change under the 2015 Rule. Other commenters on
                the proposed rule critiqued the agencies for not repeating the analysis
                used to support the 2015 Rule's EA. The agencies have determined that
                the analysis of approved jurisdictional determinations conducted for
                the 2015 Rule EA may have incorrectly assumed that the 2015 Rule would
                affect entities regulated under the CWA in direct proportion to the
                percent change in positive jurisdictional determinations. This
                proportional assumption could have yielded overestimates of costs and
                benefits of the rule. Thus, the agencies have determined that
                conducting such an analysis for this final rule would not be
                appropriate.
                 In addition, some commenters questioned the adequacy of the
                agencies' Resource and Programmatic Assessment (RPA) analyses for the
                proposed rule, primarily because the agencies did not use the NHD or
                NWI, even heavily caveated. Other commenters raised concerns about the
                lack of the quantification of potential changes in jurisdiction and
                asserted that the agencies overestimated the ability of
                [[Page 22333]]
                States to regulate additional non-jurisdictional waters. Other
                commenters noted that even though the NHD and the NWI have limitations,
                the errors associated with the datasets would underestimate, not
                overestimate, the scale of resources likely to be identified as non-
                jurisdictional under the proposed rule.
                 As discussed in the RPA for the final rule, the agencies attempted
                to use publicly available data from national datasets (i.e., the NHD
                and the NWI) to estimate the potential extent of aquatic resources
                across the country before publishing the proposed rule. The agencies
                ultimately concluded that the limitations of the datasets (e.g., errors
                of omission, errors of commission, positional inaccuracies,
                misclassification of flow regime, different definitions compared to
                both existing and proposed regulations) precluded using the NHD and the
                NWI to quantify the potential extent of waters whose CWA jurisdictional
                status could change under the proposed revised definition. Because
                these limitations still exist, the agencies decided to qualitatively
                describe the potential effects of this final rule relative to the
                baseline of the 2019 Rule as implemented.
                 Some commenters stated that the RPA and the EA for the proposed
                rule thoroughly addressed the potential impacts of the proposed revised
                definition, correctly acknowledged the technical limitations of the
                analysis and datasets, accurately noted that the avoided costs of the
                proposal far outweighed any foregone benefits it may have, and agreed
                with the agencies' decision not to rely on flawed data to perform
                comparative analyses of the proposed regulatory changes. Other
                commenters expressed support for the RPA's comprehensive analysis of
                the potential implications of the revised definition for all relevant
                CWA programs and the interplay between relevant State and federal
                regulations.
                 Recognizing that there will be limitations with any approach, in
                the RPA and EA for the final rule the agencies describe how the revised
                definition compares to the baseline of the 2019 Rule as implemented
                (i.e., the pre-2015 regulations that were recodified in 2019, and as
                interpreted by the Supreme Court and implemented consistent with those
                decisions and informed by agency guidance). See 84 FR 56626 (Oct. 22,
                2019). The documents outline the agencies' assessment of the potential
                effects of the revised definition on types of aquatic resources (e.g.,
                wetlands, tributaries, impoundments) across the country and on CWA
                programs, and the RPA provides further information on programs
                addressing aquatic resource quality under other Federal statutes. To
                further inform the final rule and in an effort to respond to comments
                received on the proposed rule analyses, the agencies conducted
                additional research on current State and tribal laws and programs to
                better understand how States and Tribes already regulate waters within
                their borders. Descriptions of State programs are in Appendix A of the
                RPA, and descriptions of tribal programs are in Appendix B of the RPA.
                 To assess the potential effects of the rule on aquatic resources,
                the agencies examined data records in the Corps' Operation and
                Maintenance Business Information Link, Regulatory Module (ORM2)
                database that documents Corps decisions regarding the jurisdictional
                status of various aquatic resource types (i.e., jurisdictional
                determinations). The aquatic resource types used in ORM2 generally
                track the Rapanos Guidance (e.g., ``relatively permanent waters,''
                ``non-relatively permanent waters'') but do not directly correlate with
                the terms used in the final rule, with limited exceptions. For the
                final rule, the agencies updated their analysis from the proposal RPA
                and EA to reflect data from ORM2 for fiscal years 2013-2018. Because of
                various limitations in accurately estimating a change in CWA
                jurisdiction, as described in Section IV of this notice, and
                uncertainties regarding the way States and Tribes might respond
                following a change in the definition of ``waters of the United
                States,'' many of the potential effects of the final rule are discussed
                qualitatively, and some are discussed quantitatively where possible.
                 As discussed in the RPA and the EA for the final rule, the agencies
                also evaluated potential effects of the final rule across CWA
                regulatory programs. The RPA and EA describe certain potential short-
                term effects for CWA regulatory programs; however, the potential long-
                term effects will depend on whether or how States and Tribes choose to
                modify their existing regulatory programs. For example, States may
                elect to make changes to their statutes or regulations to regulate
                waters that are no longer jurisdictional under the final rule. As
                discussed more fully in the EA, complete State ``gap-filling'' could
                result in a zero-net impact in the long-run.
                 Regarding the permitting programs under sections 402 and 404 of the
                CWA, the final rule will reduce the scope of waters subject to CWA
                permitting compared with the baseline of the 2019 Rule as implemented.
                For instance, the 2019 Rule, as implemented, would regulate certain
                ephemeral streams found to have a significant nexus with traditional
                navigable waters according to the 2008 Rapanos Guidance, whereas the
                revised definition in this final rule categorically excludes ephemeral
                features. Because fewer waters and wetlands are federally regulated
                under this rule relative to the 2019 Rule as implemented, the agencies
                anticipate that the regulated public would need to prepare fewer CWA
                permit applications. Additionally, some facilities currently
                discharging under a CWA section 402 permit may no longer be required to
                obtain permit coverage under federal law where there is a
                jurisdictional change to the receiving water and the receiving water
                does not convey pollutants from a point source to a water of the United
                States. The agencies note that they retain section 402 permitting
                authority over discharges that reach jurisdictional waters through
                conveyances, such as non-jurisdictional waters. In some section 402
                permits, water quality-based effluent limitations may be modified,
                subject to applicable anti-backsliding permit requirements, where a
                facility discharges to a water that is non-jurisdictional under the
                final rule, but the pollutants discharged still reach a jurisdictional
                water. Any permittee with questions about the effects of this rule
                should consult their permitting authority, as State law may be broader
                than federal authority under the CWA. A reduction in jurisdictional
                waters under the final rule may reduce the number of federal permits
                that require a section 401 certification and may reduce the
                applicability of the section 311 program and associated Oil Spill
                Liability Trust Fund, as discussed in more detail in the EA and RPA.
                 A change in the scope of CWA jurisdiction could affect existing and
                future State or tribal CWA section 303(d) lists and Total Maximum Daily
                Load (TMDL) restoration plans under section 303(d). For example, some
                States or Tribes may not assess non-jurisdictional waters, and thus may
                identify fewer waters as impaired and may develop fewer TMDLs. States
                may continue to apply their own State law-based programs to identify
                and restore impaired waters, although this activity would not be
                required under the CWA for waters that are not jurisdictional under the
                final rule. The agencies expect that States will, however, be able to
                focus their section 303(d) financial resources on a more targeted range
                of waters and could accelerate adoption of plans and standards on
                waters that may
                [[Page 22334]]
                have more ecological value. If Western States, for example, do not need
                to assess dry washes in the desert and establish CWA water quality
                standards for those typically dry ``waters,'' they can focus their
                research and restoration resources on waters with more substantial
                aquatic habitat. For additional discussion of potential effects on
                State and tribal water quality standards and section 303(d) programs,
                see the RPA.
                 Some commenters on the proposed rule raised concerns about its
                potential effects on CWA financial assistance programs. The agencies do
                not anticipate that the final rule will affect the EPA's current CWA
                financial assistance programs. With respect to CWA sections 106 and 319
                grant programs, the authorizing language and the range of programmatic
                activities are sufficiently broad that they have long addressed both
                jurisdictional and non-jurisdictional waters, so it is unlikely that a
                change in the definition of ``waters of the United States'' will affect
                the programs and funding allocations.
                 Other commenters raised concerns about potential effects of the
                proposed rule on sources of drinking water. Drinking water regulations
                under the Safe Drinking Water Act (SDWA) will continue to apply to
                water delivered by public water systems, with the goal of protecting
                public health. The Drinking Water State Revolving Fund is available to
                help fund State source water protection programs and finance
                improvements to drinking water utilities. Overall, the potential
                effects of a change in CWA jurisdiction on drinking water quality will
                depend on whether activities affecting non-jurisdictional waters also
                affect the quality of the water at a drinking water utility's water
                intake, and the capabilities of individual drinking water utilities to
                respond to a potential change in source water quality.
                 In the EA for the proposed rule, the agencies applied a two-stage
                analysis to make the best use of limited local and national level water
                resource information in their effort to assess the potential
                implications of the proposal. When the proposed rule was published, the
                agencies determined that the outputs of this two-stage analysis were
                the best way to illustrate the potential overall impact of the proposed
                rule compared to the 2015 Rule being in effect nationwide (i.e., the
                sum effect of both stages) and the 2015 Rule not being in effect (i.e.,
                second stage only). In the ``Stage 1'' analysis in the EA for the
                proposed rule, the agencies used the EA for the 2015 Rule as a starting
                point, made several updates, and developed a quantitative assessment
                limited to Stage 1. Because the 2015 Rule was repealed (84 FR 56626)
                between the proposed and final rule stages of this rulemaking, the EA
                for this final rule does not contain the Stage 1 quantitative analysis
                comparing the 2015 Rule with the pre-existing regulations.
                 The EA for the final rule incorporates an updated analysis
                depicting how States may respond to a change in CWA jurisdiction. This
                analysis of State authorities and programs was initially presented in
                the EA for the related rulemaking effort, Economic Analysis for the
                Final Rule: Definition of ``Waters of the United States''--
                Recodification of Pre-Existing Rules. Potential State responses to a
                change in the definition of a ``water of the United States'' fall along
                a continuum and depend on legal and other constraints. Some States rely
                on the federal CWA to regulate impacts to wetlands and other aquatic
                resources. These States may be affected by this action; however,
                nothing in the CWA or this final rule prevents or precludes states from
                regulating more stringently than federal requirements. Some States,
                based on limitations established in State law, cannot currently
                regulate a more expansive set of waters than those subject to the
                federal CWA definition of ``waters of the United States.'' In contrast,
                States that regulate surface waters and wetlands as broadly as or more
                broadly than the 2019 Rule as implemented, independently of the scope
                of the federal CWA, may not be affected by this action. Complete State
                ``gap-filling'' could result in no change in compliance costs to the
                regulated community and no change in environmental benefits (that is,
                neither avoided costs nor forgone benefits would occur), suggesting a
                zero-net impact in the long-run. States that fall between these
                extremes are evaluated by either including or excluding them from the
                estimates of cost savings and forgone benefits. In reality, some States
                may regulate only a subset of affected waters, but the agencies did not
                have sufficient information to incorporate that level of detail into
                the analysis.
                 Another potential outcome of the change in CWA jurisdiction is that
                State governments may be able to find more efficient ways of managing
                local resources than the Federal government, consistent with the theory
                of ``environmental federalism'' as described in the EA for the final
                rule. Depending on the value of a newly characterized non-
                jurisdictional water, States may or may not choose to regulate that
                water and the compliance costs and environmental benefits of its
                regulation could increase or decrease, respectively. In either case,
                however, net benefits would increase, assuming that a State can more
                efficiently allocate resources towards environmental protection due to
                local knowledge of amenities and constituent preferences. As effective
                regulation requires political capital and fiscal resources, however,
                the likely best indication of the way in which States will exercise
                their authority as the Federal government changes the scope of CWA
                jurisdiction is the way in which they have exercised authority in the
                past and whether the infrastructure to manage the regulatory programs
                already exists. The qualitative analysis is intended to provide
                information on the likely direction of the potential effects of the
                final rule on CWA regulatory programs.
                 In addition, the agencies conducted case studies in three major
                watersheds (Ohio River basin, Lower Missouri River basin, and Rio
                Grande River basin) to provide information for a quantitative
                assessment of the potential effects of the final rule. The case studies
                considered potential ecological effects, and their accompanying
                potential economic effects for programs implemented pursuant to
                sections 311, 402, and 404 of the CWA. Because of data limitations, the
                agencies were able to provide national-level estimates of the potential
                avoided permit and mitigation costs and forgone benefits for only the
                CWA section 404 program. The agencies developed several scenarios to
                estimate the national annual avoided costs and foregone benefits of the
                CWA section 404 program under the final rule using different
                assumptions about potential State dredged and fill regulation of
                waters. Using the same methodologies employed in the case studies,
                under scenarios assuming State regulation of dredged and fill
                activities in newly non-jurisdictional waters, the agencies estimate
                that the final rule would produce annual avoided costs ranging between
                $109 million to $264 million and annual forgone benefits ranging
                between from $55 million to $63 million. Under the scenario that
                assumes that no States will regulate dredged and fill activities in
                newly non-jurisdictional waters, an outcome the agencies believe is
                unlikely, the agencies estimate the final rule would produce annual
                avoided costs ranging from $245 million to $513 million, and annual
                forgone benefits are estimated at $173 million.
                [[Page 22335]]
                VI. Statutory and Executive Order Reviews
                A. Executive Order 12866: Regulatory Planning and Review; Executive
                Order 13563: Improving Regulation and Regulatory Review
                 This action is an ``economically significant regulatory action''
                that was submitted to the Office of Management and Budget (OMB) for
                review. Any changes made in response to OMB recommendations have been
                documented in the docket for this action. In addition, the agencies
                prepared an analysis of the potential costs and benefits associated
                with this action. This analysis is contained in the Economic Analysis
                for the Navigable Waters Protection Rule: Definition of ``Waters of the
                United States,'' which is available in the docket and briefly
                summarized in Section V. Additional analysis can be found in the
                Resource and Programmatic Assessment for the Navigable Waters
                Protection Rule: Definition of ``Waters of the United States'' which is
                also available in the docket.
                 While the economic analysis is informative in the rulemaking
                context, the agencies are not relying on the economic analysis
                performed pursuant to Executive Orders 12866 and 13563 and related
                procedural requirements as a basis for this final rule. See, e.g.,
                NAHB, 682 F.3d at 1039-40 (noting that the quality of an agency's
                economic analysis can be tested under the APA if the ``agency decides
                to rely on a cost-benefit analysis as part of its rulemaking'').
                B. Executive Order 13771: Reducing Regulation and Controlling
                Regulatory Costs
                 Pursuant to Executive Order 13771 (82 FR 9339, February 3, 2017),
                this final rule is a deregulatory action. Details on the estimated cost
                savings of this rule can be found in the Economic Analysis in the
                docket for this rule.
                C. Paperwork Reduction Act
                 This action does not impose any new information collection burden
                under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. OMB has
                previously approved the information collection activities contained in
                the existing regulations and has assigned OMB control numbers 2050-0021
                and 2050-0135 for the CWA section 311 program and 2040-0004 for the CWA
                section 402 program. For the CWA section 404 program, the current OMB
                approval number for information requirements is maintained by the Corps
                (OMB approval number 0710-0003). However, there are no new approval or
                application processes required as a result of this rulemaking that
                necessitate a new Information Collection Request (ICR).
                D. Regulatory Flexibility Act
                 The Regulatory Flexibility Act (RFA) generally requires an agency
                to prepare a regulatory flexibility analysis of any rule subject to
                notice and comment rulemaking requirements under the Administrative
                Procedure Act or any other statute unless the agency certifies that the
                rule will not have a significant economic impact on a substantial
                number of small entities. Small entities include small businesses,
                small organizations, and small governmental jurisdictions.
                 For purposes of assessing the impacts of this final rule on small
                entities, ``small entity'' is defined as: (1) A small business that is
                a small industrial entity as defined in the U.S. Small Business
                Administration's size standards (see 13 CFR 121.201); (2) a small
                governmental jurisdiction that is a government of a city, county, town,
                school district, or special district with a population of less than
                50,000; or (3) a small organization that is any not-for-profit
                enterprise that is independently owned and operated and is not dominant
                in its field.
                 The purpose of the RFA is ``to fit regulatory and informational
                requirements to the scale of the businesses, organizations and
                governmental jurisdictions subject to the regulation.'' 5 U.S.C. 601.
                Small entities subject to this final rule are largely those entities
                whose activities are directly covered by the CWA sections 402, 404, and
                311 programs. The final rule is expected to result in fewer entities
                subject to these programs, and a reduced regulatory burden for many of
                the entities that will still be subject to these programs. As a result,
                small entities subject to these regulatory programs are unlikely to
                suffer adverse impacts as a result of regulatory compliance.
                 As addressed in the Economic Analysis for the final rule, narrowing
                the scope of CWA regulatory jurisdiction over waters may result in a
                reduction in the ecosystem services provided by some waters, and as a
                result, some entities may be adversely impacted. Some business sectors
                that depend on habitat, such as those catering to hunters or anglers,
                or that require water treatment to meet production needs, could
                experience a greater impact relative to other sectors. Potential
                changes in ecosystem services are likely to be small, infrequent, and
                dispersed over wide geographic areas, thereby limiting the significance
                of these impacts on these business sectors. In addition, States and
                Tribes may already address waters potentially affected by a revised
                definition, thereby reducing forgone benefits.
                 The sectors likely to be most impacted by the rule are mitigation
                banks and companies that provide aquatic resource restoration services.
                Because fewer waters would be subject to the CWA regulation under the
                final rule than are subject to regulation under the 2019 Rule, there
                may be a reduction in demand for mitigation and restoration services
                under the section 404 permitting program. Assessing impacts to this
                sector is problematic, however, because this sector lacks a precise SBA
                small business definition, and many of the businesses that fall within
                this sector are also classified under various other North American
                Industry Classification System (NAICS) categories. Furthermore, impacts
                to this sector would not be the direct result of these businesses
                complying with the final rule, rather, they would be the indirect
                result of other entities no longer being required to mitigate for
                discharges of dredged or fill material into waters that would no longer
                be jurisdictional under the final rule. In addition, potential impacts
                would be lessened when accounting for State and tribal dredged and fill
                programs that would necessitate the purchase of mitigation credits or
                through the actions of States and Tribes that choose to regulate their
                wetlands under State or tribal law. For a more detailed discussion see
                the RFA section of the Economic Analysis for the final rule.
                 The agencies certify that this action will not have a significant
                economic impact on a substantial number of small entities under the
                RFA. In making this determination, the impact of concern is any
                significant adverse economic impact on small entities. An agency may
                certify that a rule will not have a significant economic impact on a
                substantial number of small entities if the rule relieves regulatory
                burden, has no net burden, or otherwise has a positive economic effect
                on the small entities subject to the rule. As documented in the
                Economic Analysis for the final rule, the agencies do not expect the
                cost of the rule to result in adverse impact to a significant number of
                small entities, since the rule is expected to result in net cost
                savings for all entities affected by this rule. The agencies have
                therefore concluded that this action will relieve regulatory burden to
                small entities.
                [[Page 22336]]
                E. Unfunded Mandates Reform Act
                 This final rule does not contain any unfunded mandate as described
                in the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 1531-1538,
                and does not significantly or uniquely affect small governments. The
                definition of ``waters of the United States'' applies broadly to CWA
                programs. The final action imposes no enforceable duty on any State,
                local, or tribal governments or the private sector, and does not
                contain regulatory requirements that significantly or uniquely affect
                small governments.
                F. Executive Order 13132: Federalism
                 Consulting with State and local government officials, or their
                representative national organizations, is an important step in the
                process prior to proposing regulations that may have implications for
                State and local governments under the terms of Executive Order 13132
                (64 FR 43255, August 10, 1999). State and local governments were
                engaged in a 60-day Federalism consultation at the outset of rule
                development starting on April 19, 2017. All letters received by the
                agencies during Federalism consultation may be found on in the docket
                at EPA Docket Id No. EPA-HQ-OW-2018-0149-0088, available at https://www.regulations.gov/document?D=EPA-HQ-OW-2018-0149-0088.
                 The agencies held nineteen Federalism meetings between April 19 and
                June 16, 2017. Seventeen intergovernmental associations, including nine
                of the ten organizations identified in EPA's 2008 E.O. 13132 Guidance,
                attended the initial Federalism consultation meeting, as well as
                several associations representing State and local governments.
                Organizations in attendance included: The National Governors
                Association, the National League of Cities, the National Association of
                Counties, the U.S. Conference of Mayors, the Council of State
                Governments, the National Conference of State Legislatures, the County
                Executives of America, the National Association of Towns and Townships,
                the Environmental Council of the States, the Western Governors
                Association, the National Association of Clean Water Agencies, the
                Association of Clean Water Administrators, the National Association of
                State Departments of Agriculture, the Association of State Wetlands
                Managers, the Association of State Floodplain Managers, the National
                Water Resources Association, the State/Local Legal Center, and several
                members of EPA's Local Government Advisory Committee (LGAC).
                 The LGAC met 10 times during this period to address the charge
                given to its members by the EPA Administrator on a revised rule and
                completed a report addressing the questions outlined in their charge.
                The July 14, 2017, final report can be obtained here: https://www.epa.gov/sites/production/files/2017-07/documents/lgac-final-wotusreport-july2017.pdf and in the docket as attachment to EPA Docket
                Id No. EPA-HQ-OW-2018-0149-0088, available at https://www.regulations.gov/document?D=EPA-HQ-OW-2018-0149-0088.
                 The agencies then conducted additional outreach to States prior to
                proposing the rule to ensure that the agencies could hear the
                perspectives on how the agencies might revise the definition of
                ``waters of the United States'' from State co-regulators. The agencies
                held two additional webinars, the first for Tribes, States, and local
                governments on December 12, 2017; and one for States on February 20,
                2018. In addition, one in-person meeting to seek technical input on the
                development of the proposed rule was held with a group of nine states
                (Arizona, Arkansas, Florida, Iowa, Maryland, Minnesota, Oregon,
                Pennsylvania, and Wyoming) on March 8 and 9, 2018.
                 These meetings and the letters provided by representatives provided
                a wide and diverse range of interests, positions, comments, and
                recommendations to the agencies. The agencies have prepared a report
                summarizing their consultation and additional outreach to State and
                local governments and the results of this outreach. A copy of the final
                report is available in the docket (Docket Id. No. EPA-HQ-OW-2018-0149)
                for this final rule.
                 Following publication of the proposed rule, the agencies held four
                additional in-person meetings with State representatives to answer
                clarifying questions about the proposal, and to discuss implementation
                considerations and State interest in working with the agencies to
                develop geospatial datasets of water resources as articulated in the
                preamble to the proposed rule.
                 Under the technical requirements of Executive Order 13132, agencies
                must conduct a federalism consultation as outlined in the Executive
                Order for regulations that (1) have federalism implications, that
                impose substantial direct compliance costs on state and local
                governments, and that are not required by statute; or (2) that have
                federalism implications and that preempt state law. This rule does not
                impose any new costs or other requirements on states, preempt state
                law, or limit states' policy discretion; rather, it provides more
                discretion for states as to how best to manage waters under their sole
                jurisdiction. Executive Order paras. (6)(b) and (6)(c). As discussed in
                the earlier sections of the notice, this final rule establishes a clear
                boundary between waters subject to federal regulatory requirements
                under the CWA and those that States may solely manage under their
                independent authorities. This action will not have substantial direct
                effects on the States, on the relationship between the national
                government and the States, or on the distribution of power and
                responsibilities among the various levels of government. The rule
                preserves State authority to choose whether or not to regulate waters
                that are not waters of the United States under the CWA. The agencies
                believe that the requirements of the Executive Order have been
                satisfied in any event.
                G. Executive Order 13175: Consultation and Coordination With Indian
                Tribal Governments
                 Executive Order 13175, entitled ``Consultation and Coordination
                with Indian Tribal Governments'' (65 FR 67249, Nov. 9, 2000), requires
                the agencies to develop an accountable process to ensure ``meaningful
                and timely input by tribal officials in the development of regulatory
                policies that have tribal implications.'' This action has tribal
                implications. However, it will neither impose substantial direct
                compliance costs on federally recognized tribal governments, nor
                preempt tribal law.
                 During tribal consultation and engagement efforts and in tribal
                comments on the proposed rule, many Tribes expressed concern that the
                proposed rule would or could adversely impact tribal waters. Two tribes
                supported the proposed rule and noted that it would increase the
                tribes' ability to manage and regulate their own Reservation lands. The
                agencies acknowledge that because they generally implement CWA programs
                on tribal lands, a reduced scope of CWA jurisdiction will affect Tribes
                differently than it will affect States. Currently, of the Tribes that
                are eligible, most have not received treatment in a manner similar to a
                state (TAS) status to administer CWA regulatory programs. While some
                Tribes have established tribal water programs under tribal law or have
                the authority to establish tribal programs under tribal law, many
                Tribes may lack the capacity to create a tribal water program under
                tribal law, to
                [[Page 22337]]
                administer a program, or to expand programs that currently exist. Other
                Tribes may rely on the Federal government for enforcement of water
                quality violations. Nonetheless, the rule preserves tribal authority to
                choose whether or not to regulate waters that are not covered under the
                CWA. Any decision by the Tribes to protect beyond the limits of the CWA
                is not compelled by the statute or by this final rule.
                 The EPA consulted with tribal officials under the EPA Policy on
                Consultation and Coordination with Indian Tribes early in the process
                of developing this action to permit them to have meaningful and timely
                input into its development. The Department of the Army participated in
                the consultation process and further engagement with Tribes. All
                letters received by the agencies during tribal consultation may be
                found in the docket for this action, Docket Id. No. EPA-HQ-OW-2018-
                0149.
                 The EPA initiated a tribal consultation and coordination process
                before proposing this rule by sending a ``Notification of Consultation
                and Coordination'' letter on April 20, 2017, to all of the 567 Tribes
                federally recognized at that time. The letter invited tribal leaders
                and designated consultation representatives to participate in the
                tribal consultation and coordination process. The agencies held two
                identical webinars concerning this matter for tribal representatives on
                April 27 and May 18, 2017. Tribes and tribal organizations sent 44 pre-
                proposal comment letters to the agencies as part of the consultation
                process. Of those Tribes requesting consultation, the agencies met with
                nine Tribes at a staff-level and with three Tribes at a leader-to-
                leader level pre-proposal. The agencies continued engagement with
                Tribes after the end of the formal consultation, including at national
                update webinars on December 12, 2017, and February 20, 2018, and an in-
                person tribal co-regulators workshop on March 6 and 7, 2018.
                 Following the publication of the proposed rule, the agencies held
                four in-person meetings with tribal representatives to answer
                clarifying questions about the proposal, and to discuss implementation
                considerations and tribal interest in working with the agencies to
                develop geospatial datasets of water resources as articulated in the
                preamble to the proposed rule. In addition, the agencies continued to
                meet with individual Tribes requesting consultation or engagement
                following publication of the proposed rule, holding staff-level
                meetings with four Tribes and leader-to-leader level meetings with
                eight Tribes post-proposal. The agencies also continued engaging with
                Tribes and tribal organizations via listening sessions at regional and
                national tribal meetings. In total, the agencies met with 21 individual
                Tribes requesting consultation, holding leader-to-leader level
                consultation meetings with 11 individual tribes and staff-level
                meetings with 13 individual tribes (the agencies met with some tribes
                more than once). The agencies have prepared a report summarizing the
                consultation and further engagement with tribal nations. This report,
                Summary Report of Tribal Consultation and Engagement for the Navigable
                Waters Protection Rule: Definition of ``Waters of the United States''
                (Docket Id. No. EPA-HQ-OW-2018-0149), is available in the docket for
                this final rule.
                 As required by section 7(a), the EPA's Tribal Consultation Official
                has certified that the requirements of the executive order have been
                met in a meaningful and timely manner. A copy of the certification is
                included in the docket for this action.
                H. Executive Order 13045: Protection of Children From Environmental
                Health and Safety Risks
                 This action is not subject to Executive Order 13045 (62 FR 19885,
                April 23, 1997) because the environmental health or safety risks
                addressed by this action do not present a disproportionate risk to
                children.
                I. Executive Order 13211: Actions Concerning Regulations That
                Significantly Affect Energy Supply, Distribution, or Use
                 This action is not a ``significant energy action'' as defined in
                Executive Order 13211 (66 FR 28355, May 22, 2001) because it is not
                likely to have a significant adverse effect on the supply,
                distribution, or use of energy.
                J. National Technology Transfer and Advancement Act
                 This action is not subject to the National Technology Transfer and
                Advancement Act of 1995 because the rule does not involve technical
                standards.
                K. Executive Order 12898: Federal Actions To Address Environmental
                Justice in Minority Populations and Low-Income Populations
                 This action is not subject to Executive Order 12898 (59 FR 7629,
                February 11, 1994) because there is no significant evidence of
                disproportionately high and adverse human health or environmental
                effects on minority populations, low-income populations, and/or
                indigenous peoples, as specified in Executive Order 12898.
                L. Congressional Review Act
                 This action is subject to the Congressional Review Act, and the
                agencies will submit a rule report to each House of the Congress and to
                the Comptroller General of the United States. OMB has concluded that
                this action is a ``major rule'' as defined by 5 U.S.C. 804(2).
                List of Subjects
                33 CFR Part 328
                 Navigation (water), Water pollution control, Waterways.
                40 CFR Part 110
                 Oil pollution, Reporting and recordkeeping requirements.
                40 CFR Part 112
                 Oil pollution, Penalties, Reporting and recordkeeping requirements.
                40 CFR Part 116
                 Hazardous substances, Reporting and recordkeeping requirements,
                Water pollution control.
                40 CFR Part 117
                 Hazardous substances, Penalties, Reporting and recordkeeping
                requirements, Water pollution control.
                40 CFR Part 120
                 Environmental protection, Water pollution control, Waterways.
                40 CFR Part 122
                 Administrative practice and procedure, Confidential business
                information, Environmental protection, Hazardous substances, Reporting
                and recordkeeping requirements, Water pollution control.
                40 CFR Part 230
                 Water pollution control.
                40 CFR Part 232
                 Intergovernmental relations, Water pollution control.
                40 CFR Part 300
                 Air pollution control, Carbon monoxide, Chemicals, Environmental
                protection, Greenhouse gases, Hazardous substances, Hazardous waste,
                Intergovernmental relations, Lead, Natural resources, Occupational
                safety and health, Oil pollution, Ozone, Penalties, Reporting and
                recordkeeping requirements, Sulfur Dioxide, Superfund, Volatile organic
                compounds, Water pollution control, Water supply.
                [[Page 22338]]
                40 CFR Part 302
                 Air pollution control, Chemicals, Hazardous substances, Hazardous
                waste, Intergovernmental relations, Natural resources, Reporting and
                recordkeeping requirements, Superfund, Water pollution control, Water
                supply.
                40 CFR Part 401
                 Waste treatment and disposal, Water pollution control.
                 Dated: January 23, 2020.
                Andrew R. Wheeler,
                Administrator, Environmental Protection Agency.
                 Dated: January 23, 2020.
                R.D. James,
                Assistant Secretary of the Army (Civil Works), Department of the Army.
                Title 33--Navigation and Navigable Waters
                 For the reasons set forth in the preamble, title 33, chapter II of
                the Code of Federal Regulations is amended as follows:
                PART 328--DEFINITION OF WATERS OF THE UNITED STATES
                0
                1. Authority: The authority citation for part 328 is revised read as
                follows: 33 U.S.C. 1251 et seq.
                0
                2. Section 328.3 is amended by revising paragraphs (a) through (c) and
                removing paragraphs (d) through (f) to read as follows:
                Sec. 328.3 Definitions.
                * * * * *
                 (a) Jurisdictional waters. For purposes of the Clean Water Act, 33
                U.S.C. 1251 et seq. and its implementing regulations, subject to the
                exclusions in paragraph (b) of this section, the term ``waters of the
                United States'' means:
                 (1) The territorial seas, and waters which are currently used, or
                were used in the past, or may be susceptible to use in interstate or
                foreign commerce, including waters which are subject to the ebb and
                flow of the tide;
                 (2) Tributaries;
                 (3) Lakes and ponds, and impoundments of jurisdictional waters; and
                 (4) Adjacent wetlands.
                 (b) Non-jurisdictional waters. The following are not ``waters of
                the United States'':
                 (1) Waters or water features that are not identified in paragraph
                (a)(1), (2), (3), or (4) of this section;
                 (2) Groundwater, including groundwater drained through subsurface
                drainage systems;
                 (3) Ephemeral features, including ephemeral streams, swales,
                gullies, rills, and pools;
                 (4) Diffuse stormwater run-off and directional sheet flow over
                upland;
                 (5) Ditches that are not waters identified in paragraph (a)(1) or
                (2) of this section, and those portions of ditches constructed in
                waters identified in paragraph (a)(4) of this section that do not
                satisfy the conditions of paragraph (c)(1) of this section;
                 (6) Prior converted cropland;
                 (7) Artificially irrigated areas, including fields flooded for
                agricultural production, that would revert to upland should application
                of irrigation water to that area cease;
                 (8) Artificial lakes and ponds, including water storage reservoirs
                and farm, irrigation, stock watering, and log cleaning ponds,
                constructed or excavated in upland or in non-jurisdictional waters, so
                long as those artificial lakes and ponds are not impoundments of
                jurisdictional waters that meet the conditions of paragraph (c)(6) of
                this section;
                 (9) Water-filled depressions constructed or excavated in upland or
                in non-jurisdictional waters incidental to mining or construction
                activity, and pits excavated in upland or in non-jurisdictional waters
                for the purpose of obtaining fill, sand, or gravel;
                 (10) Stormwater control features constructed or excavated in upland
                or in non-jurisdictional waters to convey, treat, infiltrate, or store
                stormwater run-off;
                 (11) Groundwater recharge, water reuse, and wastewater recycling
                structures, including detention, retention, and infiltration basins and
                ponds, constructed or excavated in upland or in non-jurisdictional
                waters; and
                 (12) Waste treatment systems.
                 (c) Definitions. In this section, the following definitions apply:
                 (1) Adjacent wetlands. The term adjacent wetlands means wetlands
                that:
                 (i) Abut, meaning to touch at least at one point or side of, a
                water identified in paragraph (a)(1), (2), or (3) of this section;
                 (ii) Are inundated by flooding from a water identified in paragraph
                (a)(1), (2), or (3) of this section in a typical year;
                 (iii) Are physically separated from a water identified in paragraph
                (a)(1), (2), or (3) of this section only by a natural berm, bank, dune,
                or similar natural feature; or
                 (iv) Are physically separated from a water identified in paragraph
                (a)(1), (2), or (3) of this section only by an artificial dike,
                barrier, or similar artificial structure so long as that structure
                allows for a direct hydrologic surface connection between the wetlands
                and the water identified in paragraph (a)(1), (2), or (3) of this
                section in a typical year, such as through a culvert, flood or tide
                gate, pump, or similar artificial feature. An adjacent wetland is
                jurisdictional in its entirety when a road or similar artificial
                structure divides the wetland, as long as the structure allows for a
                direct hydrologic surface connection through or over that structure in
                a typical year.
                 (2) Ditch. The term ditch means a constructed or excavated channel
                used to convey water.
                 (3) Ephemeral. The term ephemeral means surface water flowing or
                pooling only in direct response to precipitation (e.g., rain or snow
                fall).
                 (4) High tide line. The term high tide line means the line of
                intersection of the land with the water's surface at the maximum height
                reached by a rising tide. The high tide line may be determined, in the
                absence of actual data, by a line of oil or scum along shore objects, a
                more or less continuous deposit of fine shell or debris on the
                foreshore or berm, other physical markings or characteristics,
                vegetation lines, tidal gages, or other suitable means that delineate
                the general height reached by a rising tide. The line encompasses
                spring high tides and other high tides that occur with periodic
                frequency but does not include storm surges in which there is a
                departure from the normal or predicted reach of the tide due to the
                piling up of water against a coast by strong winds, such as those
                accompanying a hurricane or other intense storm.
                 (5) Intermittent. The term intermittent means surface water flowing
                continuously during certain times of the year and more than in direct
                response to precipitation (e.g., seasonally when the groundwater table
                is elevated or when snowpack melts).
                 (6) Lakes and ponds, and impoundments of jurisdictional waters. The
                term lakes and ponds, and impoundments of jurisdictional waters means
                standing bodies of open water that contribute surface water flow to a
                water identified in paragraph (a)(1) of this section in a typical year
                either directly or through one or more waters identified in paragraph
                (a)(2), (3), or (4) of this section. A lake, pond, or impoundment of a
                jurisdictional water does not lose its jurisdictional status if it
                contributes surface water flow to a downstream jurisdictional water in
                a typical year through a channelized non-jurisdictional surface water
                feature, through a culvert, dike, spillway, or similar artificial
                feature, or through a debris pile, boulder field, or similar natural
                feature. A lake or pond, or impoundment of a jurisdictional water
                [[Page 22339]]
                is also jurisdictional if it is inundated by flooding from a water
                identified in paragraph (a)(1), (2), or (3) of this section in a
                typical year.
                 (7) Ordinary high water mark. The term ordinary high water mark
                means that line on the shore established by the fluctuations of water
                and indicated by physical characteristics such as a clear, natural line
                impressed on the bank, shelving, changes in the character of soil,
                destruction of terrestrial vegetation, the presence of litter and
                debris, or other appropriate means that consider the characteristics of
                the surrounding areas.
                 (8) Perennial. The term perennial means surface water flowing
                continuously year-round.
                 (9) Prior converted cropland. The term prior converted cropland
                means any area that, prior to December 23, 1985, was drained or
                otherwise manipulated for the purpose, or having the effect, of making
                production of an agricultural product possible. EPA and the Corps will
                recognize designations of prior converted cropland made by the
                Secretary of Agriculture. An area is no longer considered prior
                converted cropland for purposes of the Clean Water Act when the area is
                abandoned and has reverted to wetlands, as defined in paragraph (c)(16)
                of this section. Abandonment occurs when prior converted cropland is
                not used for, or in support of, agricultural purposes at least once in
                the immediately preceding five years. For the purposes of the Clean
                Water Act, the EPA Administrator shall have the final authority to
                determine whether prior converted cropland has been abandoned.
                 (10) Snowpack. The term snowpack means layers of snow that
                accumulate over extended periods of time in certain geographic regions
                or at high elevation (e.g., in northern climes or mountainous regions).
                 (11) Tidal waters and waters subject to the ebb and flow of the
                tide. The terms tidal waters and waters subject to the ebb and flow of
                the tide mean those waters that rise and fall in a predictable and
                measurable rhythm or cycle due to the gravitational pulls of the moon
                and sun. Tidal waters and waters subject to the ebb and flow of the
                tide end where the rise and fall of the water surface can no longer be
                practically measured in a predictable rhythm due to masking by
                hydrologic, wind, or other effects.
                 (12) Tributary. The term tributary means a river, stream, or
                similar naturally occurring surface water channel that contributes
                surface water flow to a water identified in paragraph (a)(1) of this
                section in a typical year either directly or through one or more waters
                identified in paragraph (a)(2), (3), or (4) of this section. A
                tributary must be perennial or intermittent in a typical year. The
                alteration or relocation of a tributary does not modify its
                jurisdictional status as long as it continues to satisfy the flow
                conditions of this definition. A tributary does not lose its
                jurisdictional status if it contributes surface water flow to a
                downstream jurisdictional water in a typical year through a channelized
                non-jurisdictional surface water feature, through a subterranean river,
                through a culvert, dam, tunnel, or similar artificial feature, or
                through a debris pile, boulder field, or similar natural feature. The
                term tributary includes a ditch that either relocates a tributary, is
                constructed in a tributary, or is constructed in an adjacent wetland as
                long as the ditch satisfies the flow conditions of this definition.
                 (13) Typical year. The term typical year means when precipitation
                and other climatic variables are within the normal periodic range
                (e.g., seasonally, annually) for the geographic area of the applicable
                aquatic resource based on a rolling thirty-year period.
                 (14) Upland. The term upland means any land area that under normal
                circumstances does not satisfy all three wetland factors (i.e.,
                hydrology, hydrophytic vegetation, hydric soils) identified in
                paragraph (c)(16) of this section, and does not lie below the ordinary
                high water mark or the high tide line of a jurisdictional water.
                 (15) Waste treatment system. The term waste treatment system
                includes all components, including lagoons and treatment ponds (such as
                settling or cooling ponds), designed to either convey or retain,
                concentrate, settle, reduce, or remove pollutants, either actively or
                passively, from wastewater prior to discharge (or eliminating any such
                discharge).
                 (16) Wetlands. The term wetlands means areas that are inundated or
                saturated by surface or ground water at a frequency and duration
                sufficient to support, and that under normal circumstances do support,
                a prevalence of vegetation typically adapted for life in saturated soil
                conditions. Wetlands generally include swamps, marshes, bogs, and
                similar areas.
                * * * * *
                Title 40--Protection of Environment
                 For reasons set out in the preamble, title 40, chapter I of the
                Code of Federal Regulations is amended as follows:
                PART 110--DISCHARGE OF OIL
                0
                3. The authority citation for part 110 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq., 33 U.S.C. 1321(b)(3) and
                (b)(4) and 1361(a); E.O. 11735, 38 FR 21243, 3 CFR parts 1971-1975
                Comp., p. 793.
                0
                4. Section 110.1 is amended by revising the definition of ``Navigable
                waters'' and removing the definition of ``Wetlands'' to read as
                follows:
                Sec. 110.1 Definitions.
                * * * * *
                 Navigable waters means waters of the United States, including the
                territorial seas, as defined in Sec. 120.2 of this chapter.
                * * * * *
                PART 112--OIL POLLUTION PREVENTION
                0
                5. The authority citation for part 112 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq.
                0
                6. Section 112.2 is amended by revising the definition of ``Navigable
                waters'' and removing the definition of ``Wetlands'' to read as
                follows:
                Sec. 112.2 Definitions.
                * * * * *
                 Navigable waters means waters of the United States, including the
                territorial seas, as defined in Sec. 120.2 of this chapter.
                * * * * *
                PART 116--DESIGNATION OF HAZARDOUS SUBSTANCES
                0
                7. The authority citation for part 116 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq.
                0
                8. Section 116.3 is amended by revising the definition of ``Navigable
                waters'' to read as follows:
                Sec. 116.3 Definitions.
                * * * * *
                 Navigable waters means ``waters of the United States,'' including
                the territorial seas, as defined in Sec. 120.2 of this chapter.
                * * * * *
                PART 117--DETERMINATION OF REPORTABLE QUANTITIES FOR HAZARDOUS
                SUBSTANCES
                0
                9. The authority citation for part 117 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq., and Executive Order 11735,
                superseded by Executive Order 12777, 56 FR 54757.
                [[Page 22340]]
                0
                10. Section 117.1 is amended by revising paragraph (i) to read as
                follows:
                Sec. 117.1 Definitions.
                * * * * *
                 (i) Navigable waters means ``waters of the United States, including
                the territorial seas,'' as defined in Sec. 120.2 of this chapter.
                * * * * *
                0
                11. Add part 120 to read as follows:
                PART 120--DEFINITION OF WATERS OF THE UNITED STATES
                Sec.
                120.1 Purpose and scope.
                120.2 Definitions.
                 Authority: 33 U.S.C. 1251 et seq.
                Sec. 120.1 Purpose and scope.
                 Part 120 contains the definition of ``navigable waters'' and
                ``waters of the United States'' for purposes of the Clean Water Act, 33
                U.S.C. 1251 et seq. and its implementing regulations.
                Sec. 120.2 Definitions.
                 For the purposes of this part, the following terms shall have the
                meanings indicated:
                 Navigable waters means waters of the United States, including the
                territorial seas.
                 Waters of the United States means:
                 (1) Jurisdictional waters. For purposes of the Clean Water Act, 33
                U.S.C. 1251 et seq. and its implementing regulations, subject to the
                exclusions in paragraph (2) of this section, the term ``waters of the
                United States'' means:
                 (i) The territorial seas, and waters which are currently used, or
                were used in the past, or may be susceptible to use in interstate or
                foreign commerce, including waters which are subject to the ebb and
                flow of the tide;
                 (ii) Tributaries;
                 (iii) Lakes and ponds, and impoundments of jurisdictional waters;
                and
                 (iv) Adjacent wetlands.
                 (2) Non-jurisdictional waters. The following are not ``waters of
                the United States'':
                 (i) Waters or water features that are not identified in paragraph
                (1)(i), (ii), (iii), or (iv) of this definition;
                 (ii) Groundwater, including groundwater drained through subsurface
                drainage systems;
                 (iii) Ephemeral features, including ephemeral streams, swales,
                gullies, rills, and pools;
                 (iv) Diffuse stormwater run-off and directional sheet flow over
                upland;
                 (v) Ditches that are not waters identified in paragraph (1)(i) or
                (ii) of this definition, and those portions of ditches constructed in
                waters identified in paragraph (1)(iv) of this definition that do not
                satisfy the conditions of paragraph (3)(i) of this definition;
                 (vi) Prior converted cropland;
                 (vii) Artificially irrigated areas, including fields flooded for
                agricultural production, that would revert to upland should application
                of irrigation water to that area cease;
                 (viii) Artificial lakes and ponds, including water storage
                reservoirs and farm, irrigation, stock watering, and log cleaning
                ponds, constructed or excavated in upland or in non-jurisdictional
                waters, so long as those artificial lakes and ponds are not
                impoundments of jurisdictional waters that meet the conditions of
                paragraph (3)(vi) of this definition;
                 (ix) Water-filled depressions constructed or excavated in upland or
                in non-jurisdictional waters incidental to mining or construction
                activity, and pits excavated in upland or in non-jurisdictional waters
                for the purpose of obtaining fill, sand, or gravel;
                 (x) Stormwater control features constructed or excavated in upland
                or in non-jurisdictional waters to convey, treat, infiltrate, or store
                stormwater run-off;
                 (xi) Groundwater recharge, water reuse, and wastewater recycling
                structures, including detention, retention, and infiltration basins and
                ponds, constructed or excavated in upland or in non-jurisdictional
                waters; and
                 (xii) Waste treatment systems.
                 (3) Definitions. In this section, the following definitions apply:
                 (i) Adjacent wetlands. The term adjacent wetlands means wetlands
                that:
                 (A) Abut, meaning to touch at least at one point or side of, a
                water identified in paragraph (1)(i), (ii), or (iii) of this
                definition;
                 (B) Are inundated by flooding from a water identified in paragraph
                (1)(i), (ii), or (iii) of this definition in a typical year;
                 (C) Are physically separated from a water identified in paragraph
                (1)(i), (ii), or (iii) of this definition only by a natural berm, bank,
                dune, or similar natural feature; or
                 (D) Are physically separated from a water identified in paragraph
                (1)(i), (ii), or (iii) of this definition only by an artificial dike,
                barrier, or similar artificial structure so long as that structure
                allows for a direct hydrologic surface connection between the wetlands
                and the water identified in paragraph (1)(i), (ii), or (iii) of this
                definition in a typical year, such as through a culvert, flood or tide
                gate, pump, or similar artificial feature. An adjacent wetland is
                jurisdictional in its entirety when a road or similar artificial
                structure divides the wetland, as long as the structure allows for a
                direct hydrologic surface connection through or over that structure in
                a typical year.
                 (ii) Ditch. The term ditch means a constructed or excavated channel
                used to convey water.
                 (iii) Ephemeral. The term ephemeral means surface water flowing or
                pooling only in direct response to precipitation (e.g., rain or snow
                fall).
                 (iv) High tide line. The term high tide line means the line of
                intersection of the land with the water's surface at the maximum height
                reached by a rising tide. The high tide line may be determined, in the
                absence of actual data, by a line of oil or scum along shore objects, a
                more or less continuous deposit of fine shell or debris on the
                foreshore or berm, other physical markings or characteristics,
                vegetation lines, tidal gages, or other suitable means that delineate
                the general height reached by a rising tide. The line encompasses
                spring high tides and other high tides that occur with periodic
                frequency but does not include storm surges in which there is a
                departure from the normal or predicted reach of the tide due to the
                piling up of water against a coast by strong winds, such as those
                accompanying a hurricane or other intense storm.
                 (v) Intermittent. The term intermittent means surface water flowing
                continuously during certain times of the year and more than in direct
                response to precipitation (e.g., seasonally when the groundwater table
                is elevated or when snowpack melts).
                 (vi) Lakes and ponds, and impoundments of jurisdictional waters.
                The term lakes and ponds, and impoundments of jurisdictional waters
                means standing bodies of open water that contribute surface water flow
                to a water identified in paragraph (1)(i) of this definition in a
                typical year either directly or through one or more waters identified
                in paragraph (1)(ii), (iii), or (iv) of this definition. A lake, pond,
                or impoundment of a jurisdictional water does not lose its
                jurisdictional status if it contributes surface water flow to a
                downstream jurisdictional water in a typical year through a channelized
                non-jurisdictional surface water feature, through a culvert, dike,
                spillway, or similar artificial feature, or through a debris pile,
                boulder field, or similar natural feature. A lake or pond, or
                impoundment of a jurisdictional water is also jurisdictional if it is
                inundated by flooding from a water identified in paragraph (1)(i),
                (ii), or (iii) of this definition in a typical year.
                [[Page 22341]]
                 (vii) Ordinary high water mark. The term ordinary high water mark
                means that line on the shore established by the fluctuations of water
                and indicated by physical characteristics such as a clear, natural line
                impressed on the bank, shelving, changes in the character of soil,
                destruction of terrestrial vegetation, the presence of litter and
                debris, or other appropriate means that consider the characteristics of
                the surrounding areas.
                 (viii) Perennial. The term perennial means surface water flowing
                continuously year-round.
                 (ix) Prior converted cropland. The term prior converted cropland
                means any area that, prior to December 23, 1985, was drained or
                otherwise manipulated for the purpose, or having the effect, of making
                production of an agricultural product possible. EPA and the Corps will
                recognize designations of prior converted cropland made by the
                Secretary of Agriculture. An area is no longer considered prior
                converted cropland for purposes of the Clean Water Act when the area is
                abandoned and has reverted to wetlands, as defined in paragraph
                (3)(xvi) of this definition. Abandonment occurs when prior converted
                cropland is not used for, or in support of, agricultural purposes at
                least once in the immediately preceding five years. For the purposes of
                the Clean Water Act, the EPA Administrator shall have the final
                authority to determine whether prior converted cropland has been
                abandoned.
                 (x) Snowpack. The term snowpack means layers of snow that
                accumulate over extended periods of time in certain geographic regions
                or at high elevation (e.g., in northern climes or mountainous regions).
                 (xi) Tidal waters and waters subject to the ebb and flow of the
                tide. The terms tidal waters and waters subject to the ebb and flow of
                the tide mean those waters that rise and fall in a predictable and
                measurable rhythm or cycle due to the gravitational pulls of the moon
                and sun. Tidal waters and waters subject to the ebb and flow of the
                tide end where the rise and fall of the water surface can no longer be
                practically measured in a predictable rhythm due to masking by
                hydrologic, wind, or other effects.
                 (xii) Tributary. The term tributary means a river, stream, or
                similar naturally occurring surface water channel that contributes
                surface water flow to a water identified in paragraph (1)(i) of this
                definition in a typical year either directly or through one or more
                waters identified in paragraph (1)(ii), (iii), or (iv) of this
                definition. A tributary must be perennial or intermittent in a typical
                year. The alteration or relocation of a tributary does not modify its
                jurisdictional status as long as it continues to satisfy the flow
                conditions of this definition. A tributary does not lose its
                jurisdictional status if it contributes surface water flow to a
                downstream jurisdictional water in a typical year through a channelized
                non-jurisdictional surface water feature, through a subterranean river,
                through a culvert, dam, tunnel, or similar artificial feature, or
                through a debris pile, boulder field, or similar natural feature. The
                term tributary includes a ditch that either relocates a tributary, is
                constructed in a tributary, or is constructed in an adjacent wetland as
                long as the ditch satisfies the flow conditions of this definition.
                 (xiii) Typical year. The term typical year means when precipitation
                and other climatic variables are within the normal periodic range
                (e.g., seasonally, annually) for the geographic area of the applicable
                aquatic resource based on a rolling thirty-year period.
                 (xiv) Upland. The term upland means any land area that under normal
                circumstances does not satisfy all three wetland factors (i.e.,
                hydrology, hydrophytic vegetation, hydric soils) identified in
                paragraph (3)(xvi) of this definition, and does not lie below the
                ordinary high water mark or the high tide line of a jurisdictional
                water.
                 (xv) Waste treatment system. The term waste treatment system
                includes all components, including lagoons and treatment ponds (such as
                settling or cooling ponds), designed to either convey or retain,
                concentrate, settle, reduce, or remove pollutants, either actively or
                passively, from wastewater prior to discharge (or eliminating any such
                discharge).
                 (xvi) Wetlands. The term wetlands means areas that are inundated or
                saturated by surface or ground water at a frequency and duration
                sufficient to support, and that under normal circumstances do support,
                a prevalence of vegetation typically adapted for life in saturated soil
                conditions. Wetlands generally include swamps, marshes, bogs, and
                similar areas.
                PART 122--EPA ADMINISTERED PERMIT PROGRAMS: THE NATIONAL POLLUTANT
                DISCHARGE ELIMINATION SYSTEM
                0
                12. The authority citation for part 122 continues to read as follows:
                 Authority: The Clean Water Act, 33 U.S.C. 1251 et seq.
                0
                13. Section 122.2 is amended by:
                0
                a. Lifting the suspension of the last sentence of the definition of
                ``Waters of the United States'' published July 21, 1980 (45 FR 48620).
                0
                b. Revising the definition of ``Waters of the United States''.
                0
                c. Removing the definition of ``Wetlands''.
                 The revision reads as follows:
                Sec. 122.2 Definitions.
                * * * * *
                 Waters of the United States or waters of the U.S. means the term as
                it is defined in Sec. 120.2 of this chapter.
                * * * * *
                PART 230--SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF
                DISPOSAL SITES FOR DREDGED OR FILL MATERIAL
                0
                14. The authority citation for part 230 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq.
                0
                15. Section 230.3 is amended by:
                0
                a. Removing paragraph (b) and reserved paragraphs (f), (g), (j), and
                (l);
                0
                b. Redesignating paragraphs (c) through (e) as paragraphs (b) through
                (d);
                0
                c. Redesignating paragraphs (h) and (i) as paragraphs (e) and (f)
                0
                d. Redesignating paragraph (k) as paragraph (g);
                0
                e. Redesignating paragraphs (m) through (q) as paragraphs (h) through
                (l);
                0
                f. Redesignating paragraph (q-1) as paragraph (m);
                0
                g. Redesignating paragraph (r) as paragraph (n);
                0
                h. Redesignating paragraph (s) as paragraphs (o);
                0
                i. Revising newly designated paragraph (o); and
                0
                j. Removing paragraph (t).
                 The revision reads as follows:
                Sec. 230.3 Definitions.
                * * * * *
                 (o) Waters of the United States means the term as it is defined in
                Sec. 120.2 of this chapter.
                PART 232--404 PROGRAMS DEFINITIONS; EXEMPT ACTIVITIES NOT REQUIRING
                404 PERMITS
                0
                16. The authority citation for part 232 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq.
                0
                17. Section 232.2 is amended by revising the definition of ``Waters of
                the United States'' and removing the definition of ``Wetlands'' to read
                as follows:
                Sec. 232.2 Definitions.
                * * * * *
                 Waters of the United States means the term as it is defined in
                Sec. 120.2 of this chapter.
                [[Page 22342]]
                PART 300--NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION
                CONTINGENCY PLAN
                0
                18. The authority citation for part 300 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq.
                0
                19. Section 300.5 is amended by revising the definition of ``Navigable
                waters'' to read as follows:
                Sec. 300.5 Definitions.
                * * * * *
                 Navigable waters means the waters of the United States, including
                the territorial seas, as defined in Sec. 120.2 of this chapter.
                * * * * *
                0
                20. In appendix E to part 300, section 1.5 Definitions is amended by
                revising the definition of ``Navigable waters'' to read as follows:
                Appendix E to Part 300--Oil Spill Response
                * * * * *
                 1.5 Definitions. * * *
                 Navigable waters means the waters of the United States,
                including the territorial seas, as defined in Sec. 120.2 of this
                chapter.
                * * * * *
                PART 302-- DESIGNATION, REPORTABLE QUANTITIES, AND NOTIFICATION
                0
                21. The authority citation for part 302 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq.
                0
                22. Section 302.3 is amended by revising the definition of ``Navigable
                waters'' to read as follows:
                Sec. 302.3 Definitions.
                * * * * *
                 Navigable waters means the waters of the United States, including
                the territorial seas, as defined in Sec. 120.2 of this chapter.
                * * * * *
                PART 401-- GENERAL PROVISIONS
                0
                23. The authority citation for part 401 is revised to read as follows:
                 Authority: 33 U.S.C. 1251 et seq.
                0
                24. Section 401.11 is amended by revising paragraph (l) to read as
                follows:
                Sec. 401.11 General definitions.
                * * * * *
                 (l) Navigable waters means ``waters of the United States, including
                the territorial seas,'' as defined in Sec. 120.2 of this chapter.
                [FR Doc. 2020-02500 Filed 4-20-20; 8:45 am]
                 BILLING CODE 6560-50-P
                

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