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Proposed Rule2025-20402

Updated Definition of “Waters of the United States”

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Published

November 20, 2025

Issuing agencies

Defense DepartmentEngineers CorpsEnvironmental Protection Agency

Abstract

The U.S. Environmental Protection Agency (EPA) and the U.S. Department of the Army ("the agencies") are publishing for public comment a proposed rule revising the regulations defining the scope of waters federally covered under the Federal Water Pollution Control Act, as amended, also known as the Clean Water Act, in light of the U.S. Supreme Court's 2023 decision in Sackett v. Environmental Protection Agency. With this proposed rule, the agencies intend to provide greater regulatory certainty and increase Clean Water Act program predictability and consistency by clarifying the definition of "waters of the United States." This proposed rule is also intended to implement the overall objective of the Clean Water Act to restore and maintain the quality of the Nation's waters while respecting State and Tribal authority over their own land and water resources.

Full Text

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<title>Federal Register, Volume 90 Issue 222 (Thursday, November 20, 2025)</title>
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[Federal Register Volume 90, Number 222 (Thursday, November 20, 2025)]
[Proposed Rules]
[Pages 52498-52546]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-20402]

[[Page 52497]]

Vol. 90

Thursday,

No. 222

November 20, 2025

Part II

Department of Defense

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Department of the Army, Corps of Engineers

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Environmental Protection Agency

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33 CFR Part 328

40 CFR Part 120

Updated Definition of ``Waters of the United States''; Proposed Rule

Federal Register / Vol. 90, No. 222 / Thursday, November 20, 2025 /
Proposed Rules

[[Page 52498]]

DEPARTMENT OF DEFENSE

Department of the Army, Corps of Engineers

33 CFR Part 328

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 120

[EPA-HQ-OW-2025-0322; FRL 11132.1-01-OW]
RIN 2040-AG44

Updated Definition of ``Waters of the United States''

AGENCY: Department of the Army, Corps of Engineers, Department of
Defense; and Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) and the U.S.
Department of the Army (``the agencies'') are publishing for public
comment a proposed rule revising the regulations defining the scope of
waters federally covered under the Federal Water Pollution Control Act,
as amended, also known as the Clean Water Act, in light of the U.S.
Supreme Court's 2023 decision in Sackett v. Environmental Protection
Agency. With this proposed rule, the agencies intend to provide greater
regulatory certainty and increase Clean Water Act program
predictability and consistency by clarifying the definition of ``waters
of the United States.'' This proposed rule is also intended to
implement the overall objective of the Clean Water Act to restore and
maintain the quality of the Nation's waters while respecting State and
Tribal authority over their own land and water resources.

DATES: Comments must be received on or before January 5, 2026.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OW-2025-0322, by any of the following methods:
<bullet> Federal eRulemaking Portal: <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>
(our preferred method). Follow the online instructions for submitting
comments.
<bullet> Email: <a href="/cdn-cgi/l/email-protection#703f275d341f131b1504301500115e171f06">[email&#160;protected]</a>. Include Docket ID No. EPA-HQ-OW-
2025-0322 in the subject line of the message.
<bullet> Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Water Docket, Mail Code 28221T, 1200 Pennsylvania Avenue NW,
Washington, DC 20460.
<bullet> Hand Delivery or Courier: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
The Docket Center's hours of operations are 8:30 a.m. to 4:30 p.m.,
Monday-Friday (except Federal Holidays).
Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to <a href="https://www.regulations.gov">https://www.regulations.gov</a>, including personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the ``Public Participation''
heading of the SUPPLEMENTARY INFORMATION section of this document.
The agencies will hold two hybrid public meetings, and additional
information can be found at <a href="https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities">https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities</a>. Refer to the SUPPLEMENTARY
INFORMATION section below for additional information.

FOR FURTHER INFORMATION CONTACT: Stacey Jensen, Oceans, Wetlands and
Communities Division, Office of Water (4504-T), Environmental
Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460;
telephone number: (202) 566-0657; email address: <a href="/cdn-cgi/l/email-protection#2e6d796f59415a5b5d6e4b5e4f00494158">[email&#160;protected]</a>, and
Milton Boyd, Office of the Assistant Secretary of the Army for Civil
Works, Department of the Army, 108 Army Pentagon, Washington, DC 20310-
0104; telephone number: (703) 693-3655; email address:
<a href="/cdn-cgi/l/email-protection#a0d5d3c1d2cdd98ed0c5ced4c1c7cfce8ec8d1c4c18dc1d3c18dc3d78ecdc2d88ec1d3c18dc3d78dd2c5d0cfd2d4c9cec7e0c1d2cdd98ecdc9cc">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
A. Purpose of the Regulatory Action
B. Summary of the Major Provisions of the Regulatory Action
C. Costs and Benefits
II. Public Participation
A. Written Comments
B. Participation in Virtual and In-Person Public Meetings
III. General Information
A. What action are the Agencies taking?
B. What is the Agencies' authority for taking this action?
C. What are the incremental cost savings and forgone benefits of
this action?
IV. Background
A. Legal Background
1. History of Federal Waterways Regulation
2. The Federal Water Pollution Control Act
3. U.S. Supreme Court Decisions
B. The Agencies' Rules and Regulatory Regimes
1. Pre-2015 Regulatory Regime (Prior to Sackett)
2. The 2020 Navigable Waters Protection Rule
3. January 2023 Rule
4. Conforming Rule
5. Current Applicable Regulatory Regimes
6. March 12, 2025, ``Continuous Surface Connection'' Guidance
C. WOTUS Notice and Summary of Stakeholder Outreach
1. Relatively Permanent Waters
2. Continuous Surface Connection
3. Ditches
4. Implementation
5. Additional Feedback Including Further Exclusions
V. Proposed Revised Definition
A. Basis of the Proposed Rule
B. Interstate Waters
1. Basis for Eliminating as an Independent Basis for
Jurisdiction
C. Relatively Permanent Waters
1. Definition and Scope of ``Relatively Permanent'' Waters
2. Basis for the Proposed Definition
3. Alternative Approaches
4. Definition of ``Tributary''
5. Implementation
a. Implementation of ``Relatively Permanent''
b. Implementation of Tributaries
D. ``Continuous Surface Connection''
1. Definition and Scope of ``Continuous Surface Connection''
2. Basis for the Proposed Definition
3. Alternative Approaches
4. Implementation of Adjacent Wetlands
E. Lakes and Ponds Assessed Under Paragraph (a)(5)
1. Deletion of ``Intrastate''
2. Alternative Approaches
3. Implementation
F. Exclusions From the Definition of ``Waters of the United
States''
1. The Paragraph (b)(1) Waste Treatment System Exclusion and
Paragraph (c)(11) Definition of ``Waste Treatment System''
a. The Agencies' Proposed Revisions to the Waste Treatment
System Exclusion
b. Basis for the Proposed Definition
c. Alternative Approaches
d. Implementation of the Waste Treatment System Exclusion
2. Definition of ``Prior Converted Cropland'' Under Paragraph
(c)(7) and Scope of the (b)(2) Prior Converted Cropland Exclusion
a. Basis for the Proposed Definition
b. Alternative Approaches
c. Implementation of the Prior Converted Cropland Exclusion
3. Definition of ``Ditch'' and Scope of the (b)(3) Ditch
Exclusion
a. Basis for the Proposed Definition
b. Alternative Approaches
c. Implementation of Ditch Exclusion
4. The Paragraph (b)(9) Groundwater Exclusion
a. Basis for the Proposed Exclusion
b. Implementation of Groundwater Exclusion
G. Publicly Available Jurisdictional Information and Permit Data
H. Severability
VI. Supporting Information
A. Regulatory Impact Analysis
B. Children's Health
VII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review;
Executive Order

[[Page 52499]]

13563: Improving Regulation and Regulatory Review
B. Executive Order 14192: Unleashing Prosperity Through
Deregulation
C. Paperwork Reduction Act (PRA)
D. Regulatory Flexibility Act (RFA)
E. Unfunded Mandates Reform Act (UMRA)
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 Risks and Safety Risk
I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
J. National Technology Transfer and Advancement Act

I. Executive Summary

A. Purpose of the Regulatory Action

The U.S. Environmental Protection Agency (EPA) and the U.S.
Department of the Army (Army) (together, the agencies) are seeking
public comment on a proposed rule that revises key aspects of the
definition of ``waters of the United States'' to clarify the scope of
Federal jurisdiction under the Federal Water Pollution Control Act, as
amended, also known as the Clean Water Act, in light of the U.S.
Supreme Court's May 25, 2023, decision in Sackett v. Environmental
Protection Agency, 598 U.S. 651 (2023).
In September 2023, the agencies issued a final rule without notice
and comment amending the regulations defining ``waters of the United
States'' to conform to the Supreme Court's Sackett decision. ``Revised
Definition of `Waters of the United States'; Conforming,'' 88 FR 61964
(September 8, 2023) (``Conforming Rule''). The agencies refer to the
amended regulations following the Conforming Rule as the ``Amended 2023
Rule'' because the Conforming Rule amended regulations previously
issued on January 18, 2023. See ``Revised Definition of `Waters of the
United States,' '' 88 FR 3004 (January 18, 2023).
The agencies have heard numerous concerns raised by stakeholders
about the Amended 2023 Rule, including that the Amended 2023 Rule does
not adequately comply with the Supreme Court's interpretation in
Sackett of the scope of Federal jurisdiction under the Act as well as
identifying implementation-related issues. With this action, the
agencies are proposing to revise the Amended 2023 Rule to implement the
Sackett decision, provide greater regulatory certainty, and increase
Clean Water Act program predictability and consistency by clarifying
the definition of ``waters of the United States.''
The agencies' fundamental basis for this proposed revised
definition is the text, structure, and history of the Clean Water Act
and Supreme Court precedent, taking into account other relevant
factors. This proposed revision to the definition of ``waters of the
United States'' is intended to adhere faithfully to the Supreme Court's
direction, respect the Act's careful balance between Federal authority
and State responsibilities over waters, and carry out Congress' overall
objectives 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 pursuant to the cooperative
federalism framework predicated by the Act. The agencies believe the
proposed revised definition would also ensure clarity and
predictability for Federal agencies, States, Tribes, the regulated
community, and the public, including by proposing to add definitions of
``relatively permanent'' and ``continuous surface connection'' for the
first time to the agencies' regulations and by re-establishing
definitions for ``ditch,'' ``tributary,'' ``prior converted cropland,''
and ``waste treatment system'' to ensure clear boundaries that indicate
the distinction of Federal versus State and Tribal coverage of waters.
Ultimately, the proposed rule is intended to ensure that the agencies
are operating within the scope of the Federal Government's authority
over navigable waters under the Clean Water Act and the Commerce Clause
of the U.S. Constitution.

B. Summary of the Major Provisions of the Regulatory Action

The agencies are proposing to revise the following categories of
``waters of the United States'' under 33 CFR 328.3 and 40 CFR 120.2
paragraph (a) by deleting the interstate waters category under
paragraph (a)(1)(iii) and deleting ``intrastate'' from the paragraph
(a)(5) category for lakes and ponds. In addition, ministerial changes
are proposed to add in one place and delete in another place an ``or''
from paragraph (a)(1) to conform to the deletion of the interstate
waters category. In addition, the agencies are proposing to revise the
following exclusions: the (b)(1) waste treatment system exclusion, the
(b)(2) prior converted cropland exclusion, and the (b)(3) ditch
exclusion. The agencies are also proposing to add an exclusion for
groundwater at (b)(9). The agencies are also proposing to add
definitions of ``continuous surface connection,'' ``ditch,'' ``prior
converted cropland,'' ``relatively permanent,'' ``tributary,'' ``and
waste treatment system'' in paragraph (c) of their regulations.

C. Costs and Benefits

Potential costs and benefits would be incurred as a result of
actions taken under existing Clean Water Act programs (i.e., sections
303, 311, 401, 402, and 404) that implement and follow this proposed
rulemaking. Entities currently are, and would continue to be, regulated
under these programs that rely on the definition of ``waters of the
United States'' under the Clean Water Act.
The agencies prepared the Regulatory Impact Analysis for the
Proposed Rule Updated Definition of Waters of the United States
(``Regulatory Impact Analysis for the Proposed Rule''), available in
the rulemaking docket, for informational purposes to analyze the
potential cost savings and forgone benefits associated with this
proposed action. The agencies analyzed the potential cost savings and
forgone benefits against the baseline of the Amended 2023 Rule. The
analysis is summarized in section VI of this preamble.

II. Public Participation

A. Written Comments

Submit your comments, identified by Docket ID No. EPA-HQ-OW-2025-
0322, at <a href="https://www.regulations.gov">https://www.regulations.gov</a> (our preferred method), or the
other methods identified in the ADDRESSES section. Once submitted,
comments cannot be edited or removed from the docket. EPA may publish
any comment received to its public docket. Do not submit to EPA's
docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> any information you consider to
be Confidential Business Information (CBI), Proprietary Business
Information (PBI), or other information whose disclosure is restricted
by statute. Multimedia submissions (audio, video, etc.) must be
accompanied by a written comment. The written comment is considered the
official comment and should include discussion of all points you wish
to make. EPA will generally not consider comments or comment contents
located outside of the primary submission (i.e., on the web, cloud, or
other file sharing system). Please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a> for additional submission methods; the full EPA
public comment policy; information about CBI, PBI, or multimedia
submissions; and general guidance on making effective comments.

[[Page 52500]]

B. Participation in Virtual and In-Person Public Meetings

The agencies will hold two in-person public meetings, with an
option for virtual participation. To register to speak at the public
meetings, please visit <a href="https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities">https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities</a> or contact EPA staff at <a href="/cdn-cgi/l/email-protection#fe89918a8b8dd3918b8a8c9b9f9d96be9b8e9fd0999188">[email&#160;protected]</a>. On the last working day before each meeting, EPA will
post a general agenda for the meeting that will list pre-registered
speakers in approximate order at <a href="https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities">https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities</a>.
The agencies will make every effort to follow the schedule as
closely as possible on the day of the public meeting; however, please
plan for the meetings to run either ahead of schedule or behind
schedule. Additionally, requests to speak will be taken the day of the
meeting at the meeting registration desk for those participating in-
person and during the speaker waitlist for those participating
virtually. EPA and the Army will make every effort to accommodate all
speakers who arrive and register, although preferences on speaking
times may not be able to be fulfilled.
Each commenter will have three minutes to provide oral testimony.
EPA and the Army encourage commenters to provide the agencies with a
copy of their oral testimony electronically by emailing it to <a href="/cdn-cgi/l/email-protection#fc8b9388898fd19389888e999d9f94bc998c9dd29b938a">[email&#160;protected]</a>. EPA and the Army also recommend submitting the text
of your oral comments as written comments to the rulemaking docket.
The agencies may ask clarifying questions during the oral
presentations but will not respond to the presentations at that time.
Written statements and supporting information submitted during the
comment period will be considered with the same weight as oral comments
and supporting information presented at the public meeting.
Please note that any updates made to any aspect of the public
meetings are posted online at <a href="https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities">https://www.epa.gov/wotus/public-outreach-and-stakeholder-engagement-activities</a>. While EPA and the Army
expect the meetings to go forward as set forth above, please monitor
our website or contact <a href="/cdn-cgi/l/email-protection#5b2c342f2e2876342e2f293e3a38331b3e2b3a753c342d">[email&#160;protected]</a> to determine if there are
any updates. EPA and the Army do not intend to publish a document in
the Federal Register announcing updates.
The agencies will not provide audiovisual equipment for
presentations unless we receive special requests in advance. Commenters
should notify <a href="/cdn-cgi/l/email-protection#81f6eef5f4f2aceef4f5f3e4e0e2e9c1e4f1e0afe6eef7">[email&#160;protected]</a> when they pre-register to speak
that they will need specific equipment. If you require the services of
an interpreter or special accommodations such as audio description,
please pre-register for the meeting with <a href="/cdn-cgi/l/email-protection#acdbc3d8d9df81c3d9d8dec9cdcfc4ecc9dccd82cbc3da">[email&#160;protected]</a> and
describe your needs by at least one week before the meeting. The
agencies may not be able to arrange accommodations without advance
notice.

III. General Information

A. What action are the Agencies taking?

In this action, the agencies are publishing a proposed rule
revising key aspects of the definition of ``waters of the United
States'' in 33 CFR 328.3 and 40 CFR 120.2.

B. 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.

C. What are the incremental cost savings and forgone benefits of this
action?

The Regulatory Impact Analysis for the Proposed Rule assesses the
potential impacts of the changes to the definition of ``waters of the
United States'' based on the potential effects to Clean Water Act
programs that rely on the definition of ``waters of the United
States.'' The Regulatory Impact Analysis is the agencies' qualitative
assessment of the potential effects of the revised definition on the
Federal coverage of waters and water resources, including wetlands,
across the country, as well as the potential effects on Clean Water Act
programs and certain other programs under other Federal statutes. The
Regulatory Impact Analysis also provides snapshots of the applicable
regulatory and legal framework currently in place in States and some
Tribes to provide context for how aquatic resources outside of Federal
jurisdiction are covered under State and Tribal laws and regulations.
The agencies anticipate that the impacts of the proposed rule, as a
result of implementing the Sackett decision, would be most significant
for the Clean Water Act section 404 program, reducing the number of 404
permits issued and acres of wetland impacts mitigated relative to the
baseline. The agencies expect the changes to produce cost savings to
project proponents from avoided permitting and mitigation activities,
as well as potential indirect benefits from long-term reduction in
regulatory burden. The agencies also expect forgone benefits from
avoided impact minimization and mitigation measures. Notably, both the
potential cost savings and forgone benefits are contingent on a number
of factors, including decisions by States with respect to areas that
would fall solely within State or Tribal and local jurisdiction. The
agencies are considering methods to estimate the changes in the number
of 404 permits issued by the U.S. Army Corps of Engineers (Corps) and
the characteristics of the projects, notably the magnitude of wetland
impacts that would no longer be minimized and mitigated, for the final
rule Regulatory Impact Analysis. The agencies welcome input as to how
this could be accomplished, for example, using geospatial analysis and
Corps permit data. To estimate cost savings and forgone benefits for
the final rule, the agencies could use similar methodologies to those
used in previous economic analyses. In addition to direct burden
reductions, small entities may also see benefits from this proposed
rulemaking as the agencies anticipate increased opportunities and
shorter delays for approved jurisdictional determinations (AJDs) for
projects still requiring a permit due to less demand for AJDs and
clearer regulatory language.
The agencies expect the proposed rule to be deregulatory in nature,
and to have cost savings and forgone benefits. However, the agencies
have not quantified cost savings and forgone benefits for the purposes
of this proposed rule (see the Regulatory Impact Analysis for the
Proposed Rule for information on uncertainties associated with the
available data). The agencies seek input on ways that they could
address any uncertainties, on other data relevant to cost savings and
forgone benefits of the proposed rule, and on opportunities for
quantification. The agencies identify potential data and propose
potential methodologies to quantify such costs and benefits in the
Regulatory Impact Analysis. Specifically, the agencies highlight
potential approaches to quantitatively estimate the impact of the
proposed rule through changes to coverage of interstate waters,
relatively permanent waters, continuous surface connection, lakes and
ponds, and to exclusions for waste treatment systems, prior converted
cropland, and ditches. At present, the agencies do not have sufficient
information available to quantify all of the cost savings and forgone
benefits that individual States or Tribes would receive under the

[[Page 52501]]

proposed rule. Although some States and Tribes already have laws or
regulations in place that exceed the requirements of the current
regulation and/or of the proposed rule, the way States or Tribes would
interpret and apply their own laws and regulations is unknown. Further,
the extent to which States and Tribes may enact new laws or regulations
or alter their interpretations of existing laws and regulations in the
future is also unknown. Consequently, the agencies invite comment to
assess what proportion of cost savings and forgone benefits States and
Tribes would receive.
Importantly, while the potential cost savings or forgone benefits
of the rule inform the agencies' interpretation of the definition of
``waters of the United States,'' they 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 Clean Water Act. The agencies therefore do not
view the results of the Regulatory Impact Analysis as dictating the
proper interpretation of ``waters of the United States.'' In previous
rules the agencies have considered impacts as a factor in defining the
scope of ``waters of the United States.'' The agencies now recognize
that, as the Supreme Court explained in Sackett, ``the CWA does not
define the EPA's jurisdiction based on ecological importance'' or
similar impacts. 598 U.S. at 683. Rather, the impacts of faithfully
implementing the statute's jurisdictional reach are a result of ``the
Act's allocation of authority'' between the Federal Government and the
States, and States, Tribes, and localities ``can and will continue to
exercise their primary authority to combat water pollution by
regulating land and water use.'' Id. The agencies seek comment on the
view that impacts are not an appropriate decisional basis in
implementing the Act's jurisdictional scope and, if so, on what basis
and to what extent the agencies may consider such impacts.

IV. Background

A. Legal Background

1. History of Federal Waterways Regulation
Congress' authority to regulate navigable waters derives from its
Commerce Clause power over the channels of interstate commerce. See
Solid Waste Agency of Northern Cook Cnty v. Army Corps of Eng'rs, 531
U.S. 159, 168 & n.3, 172, 173-174 (2001) (SWANCC). Navigable waterways
facilitating interstate and international commerce were understood at
the Founding as an important asset worthy of protection and promotion.
See Ordinance of 1787, Sec. 14, art. IV (``The navigable waters
leading into the Mississippi and Saint Lawrence, and the carrying
places between the same, shall be common highways.''); The Federalist
No. 2, at 6 (John Jay) (Gideon Ed., Carey & McClellan eds. 2001)
(``Providence has in a particular manner blessed [the Nation] . . .
with innumerable streams, for the delight and accommodation of its
inhabitants. A succession of navigable waters forms a kind of chain
round its borders, as if to bind it together; while the most noble
rivers in the world, running at convenient distances, present them with
highways for the easy communication of friendly aids, and the mutual
transportation and exchange of their various commodities.''), No. 14,
at 65 (James Madison) (``[T]he intercourse throughout the union will be
daily facilitated by new improvements. . . . The communication between
the western and Atlantic districts, and between different parts of
each, will be rendered more and more easy, by those numerous canals,
with which the beneficence of nature has intersected our country, and
which art finds it so little difficult to connect and complete.'').
Consistent with that understanding, early authorities embraced the
concept that waterways used in navigation were subject to Federal
regulation while, at the same time, States continued to exercise
sovereign prerogative to regulate water and land within their borders.
Gibbons v. Ogden, 9 Wheat. (22 U.S.) 1, 218, 240 (1824); see Sackett,
598 U.S. at 673 (``Ever since Gibbons v. Ogden, this Court has used
`waters of the United States' to refer to similar bodies of water,
almost always in relation to ships.'').
Navigability remained the lodestar of Federal authority over water
regulation for most of our Nation's history prior to the Clean Water
Act. See Gibbons, 9 Wheat. (22 U.S.) at 193, 203 (the Commerce Clause
``has been always understood to comprehend, navigation within its
meaning,'' but did not encompass ``[i]nspection laws, quarantine laws,
health laws . . . [or] laws for regulating the internal commerce of a
State''). Even as States shifted away from common-law nuisance suits
against polluters, ``federal regulation was largely limited to ensuring
that `traditional navigable waters'--that is, interstate waters that
were either navigable in fact and used in commerce or readily
susceptible of being used in this way--remained free of impediments.''
Sackett, 598 U.S. at 659. In other words, Federal power traditionally
encompassed navigable waters capable of being used ``as a highway for
interstate or foreign commerce [and] Congress could regulate such
waters only for purposes of their navigability.'' Id. at 694 (Thomas,
J., concurring).
The navigability of United States waterways--and the extent of
Congress' authority to regulate them--has been the subject of extensive
litigation before the U.S. Supreme Court. In early cases, the Court
held that the term ``navigable'' refers to waters that are ``navigable
in fact,'' meaning that ``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.'' Daniel Ball, 10 Wall. (77 U.S.) 557, 563
(1871). Over time, the Court also recognized that Federal authority
could extend to waterways susceptible to navigation through
improvements that facilitated modern navigation. In The Montello, for
example, the Court held that waterways were susceptible to navigation,
and thus Federal authority, based on their ``capability of use by the
public for purposes of transportation and commerce'' through
improvement. 20 Wall. (87 U.S.) 430, 441-42 (1874). At the same time,
not ``every small creek in which a fishing skiff or gunning canoe can
be made to float at high water'' fell within this ambit; rather, ``to
give it the character of a navigable stream, it must be generally and
commonly useful to some purpose of trade.'' Id. Thus, Federal
``authority over navigable waters'' extended to `` `regulating and
improving navigation.' '' Sackett, 598 U.S. at 688 (Thomas, J.,
concurring) (quoting Gibson v. United States, 166 U.S. 269, 271-72
(1897)).
After the Supreme Court found that no Federal law banned
obstructions of navigable waterways, see Willamette Iron Bridge Co. v.
Hatch, 125 U.S. 1 (1888), Congress responded by enacting the Rivers and
Harbors Act of 1899 (RHA). Section 10 of the RHA prohibits ``[t]he
creation of any obstruction . . . to the navigable capacity of any of
the waters of the United States,'' requires a permit to build
``structures in any . . . water of the United States,'' and makes it
unlawful ``to excavate or fill, or in any manner to alter or modify the
course, location, condition, or capacity'' of any water, ``within the
limits of any breakwater, or of the channel of any navigable water of
the United States.'' 33 U.S.C. 403. Section 13 of the RHA,

[[Page 52502]]

often called the Refuse Act, made it illegal to dump refuse ``into any
navigable waters of the United States, or into any tributary of any
navigable water,'' and gave the Corps the authority to regulate certain
discharges into navigable waters of the United States. Id.; 33 U.S.C.
407. In interpreting the RHA, the Supreme Court reaffirmed the
principle that Federal authority over waters arose from navigability
and that States may continue to exercise their traditional authority
over land and water.\1\
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\1\ The Corps currently defines the scope of ``navigable waters
of the United States'' under the RHA as encompassing ``those waters
that are subject to the ebb and flow of the tide and/or are
presently used, or have been used in the past, or may be susceptible
for use to transport interstate or foreign commerce.'' 33 CFR 329.4.
This definition does not apply to the scope of ``waters of the
United States'' under the Clean Water Act. See 33 CFR 329.1.
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Over time, the Federal Government began applying the RHA, and the
Refuse Act in particular, to regulate pollution that interfered with
the navigable waters of the United States. See, e.g., United States v.
Standard Oil, 384 U.S. 224 (1966) (holding commercially valuable
substances such as oil could be considered refuse); United States v.
Republic Steel Corp., 362 U.S. 482 (1960) (holding industrial solid
waste is refuse); see also SWANCC, 531 U.S. at 178 (Stevens, J.,
dissenting) (``the goals of federal water regulation began to shift
away from an exclusive focus on protecting navigability and toward a
concern for preventing environmental degradation.''). Federal
regulators sought to adopt an ex ante permitting scheme for discharges,
but courts held that the Refuse Act provided insufficient authority.
See, e.g., Kalur v. Resor, 335 F. Supp. 1, 10-11 (D.D.C. 1972). When
these concerns and others prompted Congress to further legislative
action, ``a comprehensive program for controlling and abating water
pollution'' was born. SWANCC, 531 U.S. at 179 (Stevens, J., dissenting)
(quoting Train v. City of New York, 420 U.S. 35, 37 (1975)).
2. The Federal Water Pollution Control Act
Prior to 1972, the ability to control and redress water pollution
in the Nation's waters largely fell to the Corps under the 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 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 Act 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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\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 Clean Water
Act, 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) by amending the Federal Water Pollution Control Act,
also known as the Clean Water Act, 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.\3\
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, defined in the Act as ``the waters of the United
States, including the territorial seas,'' 33 U.S.C. 1362(7). 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'').
---------------------------------------------------------------------------

\3\ Following amendments in 1972 and 1977, the Federal Water
Pollution Control Act became more commonly referred to as the Clean
Water Act. See Public Law 92-500, 86 Stat. 816 (1972); Public Law
95-217, 91 Stat. 1566 (1977). In this document, for ease of
reference, the agencies will generally refer to the Act as the Clean
Water Act or the Act.
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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. 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.'' Id. 1251(a)(3)-(7).
Congress recognized that States retained primary authority over the
regulation of water and land within their borders and, at the same
time, provided a major role for the States in implementing the Clean
Water Act. 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.'' Id. 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. 1370.\4\
---------------------------------------------------------------------------

\4\ 33 U.S.C. 1370 also prohibits authorized States from
adopting any limitations, prohibitions, or standards that are less
stringent than required by the Clean Water Act.
---------------------------------------------------------------------------

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,'' id.
1362(19), in keeping with the objective of the Act ``to restore and

[[Page 52503]]

maintain the chemical, physical, and biological integrity of the
Nation's waters.'' Id. 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,'' authorizes 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.
1255(a)(1) (emphasis added). Section 105 also authorizes 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. 1255(b)-(c) (emphasis
added); see also id. 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,'' authorizes
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. 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.
1267(a)(3), Long Island Sound, see id. 1269(c)(2)(D), and Lake
Champlain, see id. 1270(g)(2).
In addition to the Act's non-regulatory measures to control
pollution of the Nation's waters generally, Congress created a
permitting program designed to address the discharge of pollutants into
a subset of those waters identified as ``navigable waters.'' Id.
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. 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. 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. 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 Clean Water Act. Under section 402
of the Clean Water Act, a National Pollutant Discharge Elimination
System (NPDES) permit is required where a point source discharges a
pollutant to ``waters of the United States.'' \5\ Id. 1342. Clean Water
Act section 404 requires a permit before dredged or fill material may
be discharged to ``waters of the United States,'' with exemptions for
certain activities, including normal farming, ranching, and forestry
activities.\6\ Id. 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.''
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\5\ The term ``point source'' is defined in Clean Water Act
section 502(14) and 40 CFR 122.2 to include ``any discernible,
confined and discrete conveyance . . . from which pollutants are or
may be discharged.'' This definition specifically excludes return
flows from irrigated agriculture and agricultural stormwater runoff.
See also infra note 8 (discussing discharges of pollutants subject
to the section 402 program).
\6\ Clean Water Act section 404(f) exempts several activities
from the section 404 permitting requirement including many ``normal
farming, silviculture, and ranching activities'' and the
``construction or maintenance of farm or stock ponds or irrigation
ditches, or the maintenance of drainage ditches.'' 33 U.S.C.
1344(f)(1).
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Fundamental principles of statutory interpretation support this
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) (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 Tex. v. Timbers of Inwood Forest Assocs., 484 U.S. 365,
371 (1988) (``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 Clean
Water Act 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. See Sackett,
598 U.S. at 661, 673 (recognizing distinction between a predecessor
statute's definition of ``interstate or navigable waters'' and the
Act's definition of ``navigable waters''); 674 (``It is hard to see how
the States' role in regulating water resources would remain `primary'
if the EPA had jurisdiction over anything defined by the presence of
water.'').
The term ``navigable waters'' is used in most of the key programs
established by the Clean Water Act, including the section 402 and
section 404 permitting programs; the section 311 oil spill prevention,
preparedness, and response program; \7\ the water quality standards,

[[Page 52504]]

impaired waters, and total maximum daily load programs under section
303; and the section 401 State and Tribal water quality certification
process. See additional discussion on ``navigable waters'' supra.
Waters that meet the definition of ``waters of the United States'' are
often called ``covered'' or ``jurisdictional'' waters. While there is
only one definition of ``waters of the United States'' for purposes of
the Clean Water Act, there may be other contextual factors that define
the reach of a particular Clean Water Act program or provision.\8\
Additionally, as noted above, some Clean Water Act programs do not rely
on the definition of ``waters of the United States,'' such as the EPA's
financial assistance programs under the Act.\9\
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\7\ While Clean Water Act section 311 uses the phrase
``navigable waters of the United States,'' EPA has interpreted it to
have the same breadth as the phrase ``navigable waters'' used
elsewhere in section 311, and in other sections of the Clean Water
Act. See United States v. Texas Pipe Line Co., 611 F.2d 345, 347
(10th Cir. 1979); United States v. Ashland Oil & Transp. Co., 504
F.2d 1317, 1324-25 (6th Cir. 1974). In 2002, EPA revised its
regulations defining ``waters of the United States'' in 40 CFR part
112 to ensure that the rule's language was consistent with the
regulatory language used in other Clean Water Act programs. Oil
Pollution Prevention & Response; Non-Transportation-Related Onshore
& Offshore Facilities, 67 FR 47042 (July 17, 2002). A district court
vacated the rule for failure to comply with the Administrative
Procedure Act and reinstated the prior regulatory language. Am.
Petroleum Inst. v. Johnson, 541 F. Supp. 2d 165 (D.D.C. 2008).
However, EPA interprets ``navigable waters of the United States'' in
Clean Water Act section 311(b), in both the pre-2002 regulations and
the 2002 rule, to have the same meaning as ``navigable waters'' in
Clean Water Act section 502(7).
\8\ For example, the Clean Water Act section 402 permit program
regulates discharges of pollutants from ``point sources'' to
``navigable waters'' whether the pollutants reach jurisdictional
waters directly or indirectly. See United States v. Rapanos, 547
U.S. 715, 743 (2006) (Scalia, J., plurality opinion); see also Cnty.
of Maui v. Hawaii Wildlife Fund, 590 U.S. 165, 183-84 (2020)
(holding that the statute also requires a permit ``when there is the
functional equivalent of a direct discharge''). Section 402 also
regulates ``any addition of any pollutant to the waters of the
contiguous zone or the ocean from any point source other than a
vessel or other floating craft.'' See 33 U.S.C. 1362(12). As another
example, section 311 applies to ``discharges of oil or hazardous
substances into or upon the navigable waters of the United States,
adjoining shorelines, or into or upon the waters of the contiguous
zone, or in connection with activities under the Outer Continental
Shelf Lands Act [43 U.S.C. 1331 et seq.] or the Deepwater Port Act
of 1974 [33 U.S.C. 1501 et seq.], or which may affect natural
resources belonging to, appertaining to, or under the exclusive
management authority of the United States (including resources under
the Magnuson-Stevens Fishery Conservation and Management Act [16
U.S.C. 1801 et seq.]).'' Id. 1321(b)(1). And section 404(g)
authorizes EPA to approve State and Tribal assumption of the section
404 dredged and fill permitting programs for certain waters of the
United States; the Federal Government retains permitting authority
over discharges into waters used as a means to transport interstate
or foreign commerce. Id. 1344(g).
\9\ For example, with respect to the Clean Water Act sections
106 and 319 grant programs, the authorizing language and the range
of programmatic activities are sufficiently broad such 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'' would affect those programs and
funding allocations.
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Since the Federal Water Pollution Control Act Amendments of 1972,
the agencies have defined the scope of jurisdictional ``navigable
waters'' or ``waters of the United States'' in regulations. See section
IV.B of this preamble, infra, for an overview of the history of the
agencies' regulations defining ``waters of the United States.'' Most
recently, the agencies issued a revised definition of ``waters of the
United States'' in January 2023 that was then amended in September 2023
in light of the Supreme Court's Sackett decision. ``Revised Definition
of `Waters of the United States,' '' 88 FR 3004 (January 18, 2023)
(``2023 Rule''); ``Revised Definition of `Waters of the United States';
Conforming,'' 88 FR 61964, 61968 (September 8, 2023) (``Conforming
Rule''); see sections IV.B.3, IV.B.4, and IV.B.5 of this preamble,
infra, for more information about these actions. The agencies refer to
the 2023 Rule as amended by the Conforming Rule as the ``Amended 2023
Rule.''
The EPA administers the Clean Water Act except as otherwise
explicitly provided. 33 U.S.C. 1251(d). The Secretary of the Army,
through the Corps, has authority to issue permits for the discharge of
dredged or fill material pursuant to Clean Water Act section 404. Id.
1344. The United States Attorney General long ago determined that the
``ultimate administrative authority to determine the reach of the term
`navigable waters' for purposes of Sec. 404'' resides with the EPA.
Administrative Authority to Construe Sec. 404 of the Federal Water
Pollution Control Act, 43 Op. Att'y Gen. 197 (1979) (``Civiletti
Memorandum''). The Act enables the Federal Government to implement
certain Clean Water Act programs, and it gives direct grants of
authority to States and authorized Tribes for implementation and
enforcement of others.
In some cases, the Act provides States the option to administer
certain Clean Water Act programs.\10\ For example, States implement the
Clean Water Act section 401 water quality certification program and may
request approval from the EPA to administer a Clean Water Act section
402 or 404 permitting program. Moreover, consistent with the Act,
States and Tribes retain authority to implement their own programs to
protect the waters in their jurisdiction more broadly and more
stringently than the Federal Government. Section 510 of the Clean Water
Act stipulates that, unless expressly stated, nothing in the Act
precludes or denies the right of any State or Tribe to establish more
protective standards or limits than the Act.\11\
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\10\ The Clean Water Act defines ``State'' as ``a State, the
District of Columbia, the Commonwealth of Puerto Rico, the Virgin
Islands, Guam, American Samoa, the Commonwealth of the Northern
Mariana Islands, and the Trust Territory of the Pacific Islands.''
33 U.S.C. 1362(3).
\11\ Congress has provided for eligible Tribes to administer
Clean Water Act programs over their reservations and expressed a
preference for Tribal regulation of surface water quality on
reservations to ensure compliance with the goals of the statute. See
33 U.S.C. 1377; 56 FR 64876, 64878-79 (December 12, 1991). Where
appropriate, references to States in this preamble may also include
eligible Tribes.
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Under the enacted statutory scheme under Clean Water Act section
303, 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 under
section 303(d). Id. 1313(d). Section 303(d) applies to ``waters of the
United States.'' Non-jurisdictional waterbodies are not required to be
assessed or otherwise identified as impaired. Total maximum daily loads
likewise apply only to ``waters of the United States.'' Id. 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 under
section 401. Id. 1341. The definition of ``waters of the United
States'' affects where Federal permits and licenses are required and
thus where Clean Water Act section 401 certification applies.
These same regulatory authorities can be assumed by Tribes under
section 518 of the Clean Water Act, which authorizes the EPA to treat
eligible Tribes with reservations in a manner similar to States for a
variety of purposes, including administering each of the principal
Clean Water Act regulatory programs.\12\ Id. 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 Clean Water
Act. See, e.g., id. 1251(b), 1251(g), 1370, 1377(a). Currently, all
States and 83 Tribes have authority to implement section 401 water
quality certification programs. All States and 53 Tribes have
established water quality standards pursuant to section 303 of the
Clean Water Act, which form a legal basis for limitations on discharges
of pollutants to ``waters of the United States.'' At this time, 47
States and one Territory have authority

[[Page 52505]]

to administer all or portions of the Clean Water Act section 402 permit
program for those ``waters of the United States'' within their
boundaries.\13\ To date, three States (Florida, Michigan, and New
Jersey) have been approved to administer an authorized section 404
permit program for certain waters in their boundaries pursuant to
section 404(g),\14\ with two States (New Jersey and Michigan) actively
administering such programs. At present, no Tribes administer the
section 402 or 404 programs, although at least one is exploring the
possibility. For additional information regarding State and Tribal
programs, see the Regulatory Impact Analysis for the proposed rule.
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\12\ Tribes must apply for and receive EPA approval to be
eligible for treatment in a manner similar as a State (TAS) for each
Clean Water Act program they wish to administer.
\13\ Three States (Massachusetts, New Hampshire, and New Mexico)
do not currently administer any part of the Clean Water Act section
402 program.
\14\ When a State or eligible Tribe assumes a section 404
program, the Corps retains permitting authority over certain waters.
The scope of Clean Water Act 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 of
the section 404 program. Corps-retained waters are identified during
approval of a State or Tribal section 404 program, and any
modifications are approved through a formal process. 40 CFR
233.11(i), 233.14(b)(4), and 233.16. This proposed rulemaking does
not address the scope of Corps-retained waters, and nothing in this
proposed rulemaking should be interpreted to affect the process for
determining the scope of Corps-retained waters.
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Clean Water Act section 311 and the Oil Pollution Act of 1990
authorize the Oil Spill Liability Trust Fund (OSLTF) to pay for or
reimburse costs of assessing and responding to oil spills to ``waters
of the United States'' or adjoining shorelines or the Exclusive
Economic Zone.\15\ The OSLTF enables an immediate response to a spill,
including containment, countermeasures, cleanup, and disposal
activities. The OSLTF can only reimburse States and Tribes for cleanup
costs and damages to businesses and citizens (e.g., lost wages and
damages) for spills affecting waters subject to Clean Water Act
jurisdiction. EPA also lacks authority under the Clean Water Act to
take enforcement actions based on spills solely affecting waters not
subject to Clean Water Act jurisdiction under section 311(b). Moreover,
section 311 requires that EPA establish an oil spill prevention program
``to prevent discharges of oil and hazardous substances from vessels
and from onshore facilities and offshore facilities, and to contain
such discharges.'' 33 U.S.C. 1321. Discharges of pollutants, such as
oil and hazardous substances, are defined, as discussed above, as ``any
addition of any pollutant to navigable waters [i.e., `waters of the
United States'] from any point source.'' Id. at 1362(12).
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\15\ See 33 U.S.C. 1321(b) for the full jurisdictional scope of
Clean Water Act section 311.
---------------------------------------------------------------------------

The scope of facilities required to prepare oil spill prevention
and response plans is also affected by the definition of ``waters of
the United States.'' EPA-regulated oil storage facilities with storage
capacities greater than 1,320 gallons (except facilities located on
farms) that have a reasonable expectation of an oil discharge to
``waters of the United States'' or adjoining shorelines \16\ are
required to prepare and implement spill prevention plans. High-risk oil
storage facilities that meet certain higher storage thresholds and
related harm factors are required to prepare and submit oil spill
preparedness plans to EPA for review. The U.S. Coast Guard and
Department of Transportation also require oil spill response plans
under their respective authorities. However, section 311 spill
prevention and preparedness plan requirements do not apply to a
facility if there is no reasonable expectation that an oil discharge
from that facility could reach a jurisdictional water or adjoining
shoreline or the Exclusive Economic Zone.
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\16\ See supra note 7.
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It is important to note that just because a water meets the
definition of ``waters of the United States'' does not imply that
activities such as farming, construction, infrastructure development,
or resource extraction cannot take place in or near that water. For
example, the Clean Water Act exempts a number of activities from
permitting or from the definition of ``point source,'' including
agricultural storm water and irrigation return flows. See 33 U.S.C.
1342(l)(2), 1362(14). Moreover, since 1977, the Clean Water Act in
section 404(f) has exempted activities such as many ``normal farming,
silviculture, and ranching activities'' from the section 404 permitting
requirement, including seeding, harvesting, cultivating, planting, and
soil and water conservation practices. Id. 1344(f)(1). This proposed
rulemaking would not affect these statutory exemptions.
In addition, permits are routinely issued under Clean Water Act
sections 402 and 404 to authorize certain discharges to ``waters of the
United States.'' Further, under both permitting programs, the agencies
have established general permits for categories of activities that are
similar in nature. General permits provide dischargers with knowledge
about applicable requirements before dischargers may obtain coverage
under them. Obtaining coverage under a general permit is typically
quicker than obtaining coverage under an individual permit, with
coverage under a general permit often occurring immediately (depending
on how the permit is written) or after a short review period. The
permitting authority \17\ generally works with permit applicants to
ensure that activities can occur consistent with the agencies'
regulations. Thus, the permitting programs allow for discharges to
``waters of the United States'' to occur while also ensuring that those
discharges meet statutory and regulatory requirements designed to
protect water quality.\18\
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\17\ Generally, the permitting authority is either EPA or an
authorized State for the NPDES program and either the Corps or an
authorized State for the section 404 program. No eligible Tribes
have requested authority to administer a Clean Water Act section 402
or section 404 program at this time.
\18\ Regarding section 404 permits, the Corps or authorized
State works with the applicant to avoid, minimize, and compensate
for any unavoidable impacts to ``waters of the United States.'' For
most discharges that ``will cause only minimal adverse environmental
effects,'' a general permit (e.g., a ``nationwide'' permit) may be
suitable. 33 U.S.C. 1344(e)(1). General permits are issued on a
nationwide, regional, or State basis for particular categories of
activities. While some general permits require the applicant to
submit a pre-construction notification to the Corps or the State,
others allow the applicant to proceed with no formal notification.
The general permit process allows certain activities to proceed with
little or no delay, provided the general or specific conditions for
the general permit are met.
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A jurisdictional determination is ``a written Corps determination
that a wetland and/or waterbody is subject to regulatory jurisdiction
under Section 404 of the Clean Water Act (33 U.S.C. 1344) or a written
determination that a waterbody is subject to regulatory jurisdiction
under Section 9 or 10 of the Rivers and Harbors Act of 1899 (33 U.S.C.
401 et seq.).'' 33 CFR 331.2. Jurisdictional determinations are
identified as either preliminary or approved. An approved
jurisdictional determination (AJD) is ``a Corps document stating the
presence or absence of waters of the United States on a parcel or a
written statement and map identifying the limits of waters of the
United States on a parcel.'' Id. An approved jurisdictional
determination is administratively appealable and is a final agency
action subject to judicial review. U.S. Army Corps of Eng'rs v. Hawkes
Co., Inc., 578 U.S. 590 (2016). AJDs are valid for five years from the
date of issuance, unless new information warrants revision of the
determination before the expiration date. Regulatory Guidance Letter
(RGL) 05-02 (June 14, 2005). Applicants may also request a new AJD
before the five-year expiration date.

[[Page 52506]]

The agencies have consistently maintained that AJDs and permits
issued under a previous regulatory definition of ``waters of the United
States'' would still be considered valid and would not necessarily be
reopened due to a subsequent rule change, unless requested by the
landowner or applicant. See, e.g., 84 FR 56626, 56664 (October 22,
2019) (2019 Repeal Rule); 85 FR 22250, 22331-32 (April 21, 2020)
(NWPR).\19\
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\19\ An applicant or landowner may believe the permit includes
conditions that are no longer required if this proposed rulemaking
were to be finalized. If requested, the agencies stand ready to
assist the applicant or landowner, consistent with regulatory
requirements and prior practice.
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A preliminary jurisdictional determination (PJD) is a non-binding
``written indication that there may be waters of the United States on a
parcel or indications of the approximate location(s) of waters of the
United States on a parcel.'' 33 CFR 331.2. An applicant can elect to
use a PJD to voluntarily waive or set aside questions regarding Clean
Water Act jurisdiction over a particular site and thus move forward
assuming that all waters will be treated as jurisdictional without the
Corps making a formal determination. The Corps does not charge a fee
for these jurisdictional determinations. See id. 325.1 (omitting
mention of fees for jurisdictional determinations); Regulatory Guidance
Letter 16-01 (2016) (stating that such determinations are issued as a
``public service'').
3. U.S. Supreme Court Decisions
From the earliest rulemaking efforts following adoption of the 1972
Federal Water Pollution Control Act amendments, to the agencies' most
recent attempt to define ``waters of the United States'' in 2023, the
agencies' definition and interpretation of their regulations 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., Sackett, 598
U.S. at 664-59 (summarizing history); Rapanos v. United States, 547
U.S. 715, 739 (2006) (Scalia, J., plurality opinion) (same); see also
discussion supra of history of Federal waterways regulation in section
1.A.
As part of this complex litigation history, several key U.S.
Supreme Court decisions have contributed to the agencies'
interpretation of the phrase ``waters of the United States'' in the
proposed rule. See discussion of early interpretations of ``navigable
waters'' and ``waters of the United States'' supra in section 1.A. The
agencies note that, in the first instance, the Court has long
interpreted the term ``navigable waters'' to mean waters used in
interstate commerce. See, e.g., Daniel Ball, 10 Wall. (77 U.S.) at 563;
The Montello, 20 Wall. (87 U.S.) at 441-42. The Court has also used the
phrase ``waters of the United States'' in this context for centuries to
mean ``similar bodies of water, almost always in relation to ships.''
Sackett, 598 U.S. at 673 (quoting Gibbons, 9 Wheat. (22 U.S.) at 218).
As discussed in section IV.A.2 of this preamble, enactment of the
Federal Water Pollution Control Act expanded the scope of Federal
jurisdiction over waters from what was covered under the RHA. Yet as
the Supreme Court emphasized in Sackett, Federal jurisdiction under the
Clean Water Act is not unlimited. The agencies' proposal is intended to
appropriately limit the scope of Federal authority consistent with the
centuries-old boundaries of Congress' Commerce Clause authority. See
Sackett, 598 U.S. at 704 (Thomas, J., concurring).
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 ``in the majority of cases''
they have ``significant effects on water quality and the aquatic
ecosystem'' in those waters. United States v. Riverside Bayview Homes,
474 U.S. 121, 135 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 recognized that ``wetlands adjacent to lakes, rivers, streams,
and other bodies of water may function as integral parts of the aquatic
environment . . .'' Id. at 135. 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.
The Supreme Court again addressed the definition of ``waters of the
United States'' in SWANCC by rejecting 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. 531 U.S. at 172. 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. The
SWANCC Court found that Congress' ``use of the phrase `waters of the
United States' '' in the Clean Water Act is not ``a basis for reading
the term `navigable waters' out of the statute.'' Id. 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. at 172-73. The Clean
Water Act contains no such clear statement that Congress intended
Federal jurisdiction to extend to the abandoned sand and gravel pit at
issue. Id. at 174.
In January 2003, the EPA and the Corps issued joint guidance
interpreting the Supreme Court decision in SWANCC.\20\ 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.
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\20\ 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 (January 15, 2003), available at <a href="https://www.epa.gov/sites/production/files/2016-04/documents/swancc_guidance_jan_03.pdf">https://www.epa.gov/sites/production/files/2016-04/documents/swancc_guidance_jan_03.pdf</a>.
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In 2006, the Supreme Court interpreted the term ``waters of the
United States'' in Rapanos v. United States, 547 U.S. 715 (2006). In
Rapanos, the Supreme Court consolidated appeals of two Sixth Circuit
cases, United States v. Rapanos, 235 F.3d 256 (6th Cir. 2000) and
Carabell v. U.S. Army Corps of Engineers, 391 F.3d 704 (6th Cir. 2004),
in which the Clean Water Act 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. Rapanos, 547 U.S. at 731 (Scalia,
J., plurality opinion) (``We have twice stated that the meaning of
`navigable waters' in the Act is broader than the traditional
understanding of that term,

[[Page 52507]]

SWANCC, 531 U.S. at 167; Riverside Bayview, 474 U.S. at 133.'').
A four-Justice plurality in Rapanos 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,' '' id. at 739 (Scalia, J., plurality
opinion) (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 Clean
Water Act 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). The plurality said
that ``adjacent'' means ``physically abutting,'' and used ``abutting''
and ``adjacent'' interchangeably. Id. at 748; see also id. at 742
(``Riverside Bayview rested upon the inherent ambiguity in defining
where water ends and abutting (``adjacent'') wetlands begin[.]''). The
plurality clarified that ``the statutory definition [of `navigable
waters' at 33 U.S.C. 1362(7)] can be read to include some wetlands--
namely, those that directly `abut' covered waters.'' Id. at 747 n.12
(emphasis in original). The plurality also explained how its standard
for Clean Water Act jurisdiction remained consistent with the Court's
precedent interpreting ``waters of the United States,'' including
Riverside Bayview. See id. at 734-35, 740-42, 746-48 (Scalia, J.,
plurality opinion).
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.''
Id. 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, Federal courts took different approaches to
determining which Rapanos standard applied. 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'').\21\ 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 Clean Water Act.
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\21\ 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 (December
2, 2008) (``Rapanos Guidance''), available at <a href="https://www.epa.gov/sites/production/files/2016-02/documents/cwa_jurisdiction_following_rapanos120208.pdf">https://www.epa.gov/sites/production/files/2016-02/documents/cwa_jurisdiction_following_rapanos120208.pdf</a>.
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On May 25, 2023, the Supreme Court decided Sackett v. EPA. In its
majority opinion, the Supreme Court held that the Clean Water Act
extends to relatively permanent bodies of water connected to
traditional navigable waters and wetlands with a continuous surface
connection to those waters ``so that there is no clear demarcation
between `waters' and wetlands.'' 598 U.S. 651, 678 (quoting Rapanos,
547 U.S. at 742, 755 (plurality opinion)). The Court concluded that the
significant nexus standard was ``inconsistent with the text and
structure of the [Clean Water Act].'' Id. at 679. Instead, the Court
held that the Rapanos plurality was correct: the [Clean Water Act]'s
use of `waters' encompasses `only those relatively permanent, standing
or continuously flowing bodies of water ``forming geographic[al]
features'' that are described in ordinary parlance as ``streams,
oceans, rivers, and lakes.'' ' '' Id. at 671 (quoting Rapanos, 547 U.S.
at 739). The Court also ``agree[d] with [the plurality's] formulation
of when wetlands are part of `the waters of the United States,' '' id.
at 678, explaining:

In Rapanos, the plurality spelled out clearly when adjacent
wetlands are part of covered waters. It explained that ``waters''
may fairly be read to include only those wetlands that are ``as a
practical matter indistinguishable from waters of the United
States,'' such that it is ``difficult to determine where the `water'
ends and the `wetland' begins.'' That occurs when wetlands have ``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.''

Id. at 678 (citing Rapanos, 547 U.S. at 742, 755).
The Sackett Court also found that ``[w]etlands that are separate
from traditional navigable waters cannot be considered part of those
waters, even if they are located nearby,'' id. at 678, and that ``
`adjacent' cannot include wetlands that are not part of covered
`waters,' '' id. at 682. Additionally, the Court found it
``instructive'' that section 101(b) of the Act expressly ``protect[s]
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,'' observing that ``[i]t is hard to see how
the States' role in regulating water resources would remain `primary'
if the [agencies] had jurisdiction over anything defined by the
presence of water.'' Id. at 674. Finally, the Court emphasized that
``the CWA does not define the EPA's jurisdiction based on ecological
importance'' and instead draws a careful balance that recognizes
States' ``primary authority to combat water pollution by regulating
land and water use.'' Id. at 683.

B. The Agencies' Rules and Regulatory Regimes

In May 1973, the EPA issued its first set of regulations to
implement the new NPDES permit program established in the 1972 Federal
Water Pollution Control Act amendments. Those regulations defined the
phrase ``navigable waters'' as:
<bullet> All navigable waters of the United States;

[[Page 52508]]

<bullet> Tributaries of navigable waters of the United States;
<bullet> Interstate waters;
<bullet> Intrastate lakes, rivers, and streams which are utilized
by interstate travelers for recreational or other purposes;
<bullet> Intrastate lakes, rivers, and streams from which fish or
shellfish are taken and sold in interstate commerce; and
<bullet> 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 the
term ``navigable waters'' for the purpose of implementing section 404
of the Clean Water Act as well as sections 9, 10, 11, 13, and 14 of the
Rivers and Harbors Act. 39 FR 12115, 12119 (April 3, 1974) (codified at
33 CFR 209.120). These regulations reaffirmed the Corps' view at the
time that its dredged and fill jurisdiction under section 404 was the
same as its traditional jurisdiction under the Rivers and Harbors Act.
Specifically, the Corps defined the ``navigable waters'' 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. In a brief summary
judgment order, 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 (July 19, 1977).
The agencies have revised the definition of ``waters of the United
States'' multiple times since then.\22\ In fact, since 2015, EPA and
the Army have finalized five rules revising the definition of ``waters
of the United States.'' Additional information regarding the agencies'
prior rulemakings on ``waters of the United States,'' including the
2015 Clean Water Rule and the 2019 Repeal Rule, can be found in the
preambles for the agencies' prior rules.\23\ The remainder of section
IV.B of this preamble focuses on the agencies' most recent rules and
regulatory regimes--namely, the pre-2015 regulatory regime, the 2020
Navigable Waters Protection Rule, the 2023 Rule, the Conforming Rule,
and resulting Amended 2023 Rule regulatory regime.
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\22\ The Corps has revised the definition of ``navigable
waters'' or ``waters of the United States'' for its section 404
regulations in 1975 (40 FR 31320, 31324, 31326 (July 25, 1975)
(interim final regulations)), 1977 (42 FR 37122, 37144 (July 19,
1977) (including a definition of ``wetlands''; ``freshwater
wetlands'' had been defined in 1975)), 1982 (47 FR 31794 (July 22,
1982) (interim final regulations)), 1984 (49 FR 39478 (October 5,
1984)), and 1986 (51 FR 41250 (November 13, 1986)). For its part,
EPA has revised the definition of ``navigable waters'' or ``waters
of the United States'' in 1979 (44 FR 32854 (June 7, 1979)
(promulgating the waste treatment system exclusion)), 1980 (45 FR
48620 (July 21, 1980) (revising the waste treatment system exclusion
in its NPDES regulations only at 40 CFR 122.3) and 45 FR 48620 (July
21, 1980) (suspending a portion of the waste treatment system
exclusion in its NPDES regulations)), 1983 (48 FR 14146, 14157
(April 1, 1983) (republishing the waste treatment system exclusion
in its NPDES regulations at 40 CFR 122.2)), 1988 (53 FR 20764, 20774
(June 6, 1988) (revising EPA's section 404 program definitions at 40
CFR 232.2)), and 2002 (67 FR 47042 (July 17, 2002) (revising the
definition of ``waters of the United States'' in EPA's section 311
regulations at 40 CFR part 112 to ensure consistency with other
Clean Water Act programs)). The agencies have also issued several
joint revisions to their regulations, including in 1993 (58 FR
45008, 45031 (August 25, 1993) (adding an exclusion for prior
converted cropland)), 2015 (80 FR 37045 (June 29, 2015) (``Clean
Water Rule: Definition of `Waters of the United States' '' or 2015
Clean Water Rule)), 2019 (84 FR 56626 (October 22, 2019)
(``Definition of `Waters of the United States'--Recodification of
Pre-Existing Rules'' or the 2019 Repeal Rule)), 2020 (85 FR 22250
(April 21, 2020) (``Navigable Waters Protection Rule'')), and 2023
(88 FR 3004 (January 18, 2023) (``Revised Definition of `Waters of
the United States' '') and 88 FR 61964, 61968 (September 8, 2023)
(``Revised Definition of `Waters of the United States' ;
Conforming'')).
\23\ See supra note 22.
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1. Pre-2015 Regulatory Regime (Prior to Sackett)
The ``pre-2015 regulatory regime'' refers to the agencies' pre-2015
regulations defining ``waters of the United States,'' implemented in
light of relevant case law and longstanding practice, as informed by
applicable guidance, training, and experience. The pre-2015 regulations
are commonly referred to as ``the 1986 regulations.''
In 1986, the Corps consolidated and recodified its regulations
defining ``waters of the United States'' for purposes of implementing
the section 404 program to align with clarifications that the EPA had
previously promulgated. See 51 FR 41206, 41216-17 (November 13, 1986).
While EPA and the Corps have maintained separate regulations defining
the statutory term ``waters of the United States,'' their
interpretations, reflected in the 1986 regulations, were identical and
remained largely unchanged from 1977 to 2015. See 42 FR 37122, 37124,
37127 (July 19, 1977).24 25 EPA's comparable regulations
were recodified in 1988. See 53 FR 20764 (June 6, 1988). 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 irrigate crops sold in interstate commerce. Id. at 41217.
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\24\ Multiple provisions in the Code of Federal Regulations
contained the definition of the phrases ``navigable waters'' and
``waters of the United States'' for purposes of implementing the
Clean Water Act, 33 U.S.C. 1362(7), and other water pollution
protection statutes such as the Oil Pollution Act, 33 U.S.C.
2701(21). Some EPA definitions were added after 1986, but each
conformed to the 1986 regulations except for variations in the waste
treatment system exclusion. See, e.g., 55 FR 8666 (March 8, 1990);
73 FR 71941 (November 26, 2008); see also supra note 22.
\25\ For convenience, the agencies generally refer to the Corps'
regulations throughout this document at 33 CFR 328.3. The EPA's
codification of the definition of ``waters of the United States'' is
found at 40 CFR 120.2. EPA's regulations defining ``waters of the
United States'' or ``navigable waters'' 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 all refer to the definition at 40 CFR 120.2.
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The 1986 regulatory text identified the following waters as
``waters of the United States'' (33 CFR 328.3 (2014)): \26\
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\26\ ``Waters of the United States'' is defined in both the U.S.
Army Corps of Engineers' regulations, at 33 CFR part 328, and in the
EPA's regulations, at 40 CFR part 120. For the sake of convenience,
in this preamble the agencies will generally just refer to the
Corps' regulations at 33 CFR 328.3.

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[[Page 52509]]

<bullet> All traditional navigable waters,\27\ interstate waters,
and the territorial seas;
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\27\ ``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.
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<bullet> All impoundments of jurisdictional waters;
<bullet> All ``other waters'' such as lakes, ponds, and sloughs the
``use, degradation, or destruction of which would or could affect
interstate or foreign commerce'' (``other waters'');
<bullet> Tributaries of traditional navigable waters, interstate
waters, impoundments, or ``other waters''; and
<bullet> 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 regulations also excluded
``waste treatment systems'' from the definition of ``waters of the
United States,'' consistent with the EPA's regulatory definition. Id.
328.3 (a)(7), (b) (1987); see also 44 FR 32854 (June 7, 1979).\28\
Additionally, the 1986 regulations defined ``adjacent'' to mean
``bordering, contiguous, or neighboring,'' and specified that
``[w]etlands separated from other waters of the United States by man-
made dikes or barriers, natural river berms, beach dunes and the like
are `adjacent wetlands.' ''
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\28\ There are some variations in the waste treatment system
exclusion across the EPA's regulations defining ``waters of the
United States.'' The placement of the waste treatment system and
prior converted cropland exclusions also varies in the EPA's
regulations.
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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 (August 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 programs implemented by the U.S. Department of Agriculture (USDA)
and the Clean Water Act programs implemented by the agencies.\29\ 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 [prior converted]
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.
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\29\ 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 Resources 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 Food Security Act, USDA wetland
determinations may identify certain areas as exempt under the 1985
Act but remain subject to the requirements of the Clean Water Act.
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 information as to whether
a particular activity will require a Clean Water Act section 404
permit.
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Congress amended the Food Security Act wetland conservation
provisions in 1996 to state that USDA certifications of wetland
delineation maps for purposes of the Food Security Act (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 meant that prior converted cropland would only be
abandoned if the area was no longer devoted to an agriculture use,
while the 1993 preamble abandonment principles would have disqualified
such areas for the Clean Water Act exclusion if their specific
conditions were not met. The agencies did not update their prior
converted cropland regulations for purposes of the Clean Water Act
following the 1996 amendments to wetland conservation provisions of the
Food Security Act, 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
the USDA issued a joint Memorandum to the Field (the 2005 Memorandum)
in an effort to align the Clean Water Act section 404 program with the
Food Security Act wetland conservation provisions.\30\ 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.
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\30\ U.S. Department of Agriculture, Natural Resources
Conservation Service and U.S. Department of the Army, Office of the
Assistant Secretary of the Army (Civil Works). 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 <a href="https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2508">https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2508</a>.
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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). As discussed in section V.F.2 of this
preamble, USDA and the Army rescinded the 2005 Memorandum in 2020 in
light of promulgation of the NWPR.\31\ Thus, under pre-2015 practice,
EPA and the Army once again began implementing the abandonment
principle to determine if an area has lost its prior converted cropland
status.
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\31\ U.S. Department of the Army, Office of the Assistant
Secretary of the Army (Civil Works), and U.S. Department of
Agriculture, Natural Resources Conservation Service. 2020.
``Memorandum for the Field: Rescission of the 2005 Joint Memorandum
to the Field Regarding Guidance on Conducting Wetland Determinations
for the Food Security Act of 1985 and Section 404 of the Clean Water
Act.'' January 28, 2020. Available in the docket for this action.
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The agencies have implemented the pre-2015 regulatory regime
consistent

[[Page 52510]]

with SWANCC and Rapanos after those Supreme Court decisions were issued
in 2001 and 2006, respectively. The agencies issued guidance on SWANCC
in 2001 and then in 2003. 68 FR 1991 (January 15, 2003) (superseding
the agencies' 2001 guidance). To ensure that any assertion of
jurisdiction over the ``other waters'' category (i.e., paragraph (a)(3)
waters in the 1986 regulations) is consistent with the Supreme Court's
ruling in SWANCC, the agencies have required that field staff get
approval from headquarters before exercising jurisdiction over an
(a)(3) water. As a practical matter, field staff have rarely, if ever,
sought such approval and therefore the agencies have not asserted
jurisdiction under the ``other waters'' category of the 1986
regulations since SWANCC.
For nearly a decade after Rapanos, the agencies did not revise
their regulations but instead determined jurisdiction under the 1986
regulations consistent with the two standards established in Rapanos
(the plurality's relatively permanent standard and Justice Kennedy's
significant nexus standard) and by using guidance issued jointly by the
agencies. See Rapanos Guidance. Under the Rapanos Guidance,\32\ the
agencies concluded that Clean Water Act jurisdiction exists if a water
meets either the relatively permanent standard or the significant nexus
standard. The agencies' assertion of jurisdiction over traditional
navigable waters and their adjacent wetlands remained unchanged by
Rapanos. Under the relatively permanent standard, the guidance stated
that the agencies would assert jurisdiction over: non-navigable
tributaries of traditional navigable waters that typically flow year-
round or have continuous flow at least seasonally; and wetlands that
directly abut such tributaries. Id. at 4-7. The guidance further stated
that the agencies would determine jurisdiction under the significant
nexus standard for the following waters: non-navigable tributaries that
are not relatively permanent, wetlands adjacent to non-navigable
tributaries that are not relatively permanent, and wetlands adjacent to
but not directly abutting a relatively permanent non-navigable
tributary. Id. at 8-12. The agencies generally did not assert
jurisdiction over non-wetland swales or erosional features (e.g.,
gullies and small washes characterized by low volume or infrequent or
short duration flow) or ditches (including roadside ditches) excavated
wholly in and draining only uplands and that did not carry a relatively
permanent flow of water. Id. at 11-12.
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\32\ The agencies note that the guidance ``does not impose
legally binding requirements on EPA, the Corps, or the regulated
community, and may not apply to a particular situation depending on
the circumstances.'' Rapanos Guidance at 4 n.17.
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Even after promulgating a revised definition of ``waters of the
United States'' that went into effect in 2015 (the 2015 Clean Water
Rule), the agencies continued implementing the pre-2015 regulatory
regime in certain States and, for a period of time, nationwide due to
court orders staying implementation of the 2015 rule.\33\ In 2018, the
agencies again implemented the pre-2015 regulatory regime nationwide
for about six months following the agencies' addition of an
applicability date to the 2015 Clean Water Rule.\34\ The next year,
after proceeding through public notice and comment, the agencies
published a final rule repealing the 2015 Clean Water Rule and
recodifying the 1986 regulations without any changes to the regulatory
text. 84 FR 56626 (October 22, 2019). The agencies indicated that they
would implement the 1986 regulations informed by applicable agency
guidance documents and consistent with Supreme Court decisions and
longstanding agency practice, thus restoring implementation of the pre-
2015 regulatory regime nationwide after the 2019 Repeal Rule went into
effect on December 23, 2019.
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\33\ See, e.g., North Dakota v. EPA, 127 F. Supp. 3d 1047
(D.N.D. 2015) (preliminary injunction barring implementation of the
2015 Clean Water Rule in 13 States); Georgia v. Pruitt, 326 F. Supp.
3d 1356 (S.D. Ga. June 6, 2018) (same as to 11 States); Texas v.
EPA, No. 3:15-cv-162, 2018 WL 4518230 (S.D. Tex. Sept. 12, 2018)
(same as to three States). See section I.A of the Technical Support
Document for the Proposed ``Revised Definition of `Waters of the
United States' '' Rule (available at <a href="https://www.regulations.gov/document/EPA-HQ-OW-2021-0602-0081">https://www.regulations.gov/document/EPA-HQ-OW-2021-0602-0081</a>), for a comprehensive history of
the effects of the litigation against the 2015 Clean Water Rule.
\34\ In February 2018, the agencies issued a rule that added an
applicability date of February 6, 2020 to the 2015 Clean Water Rule.
83 FR 5200 (February 6, 2018) (``Applicability Date Rule''). The
Applicability Date Rule was challenged in several district court
actions, and on August 16, 2018 the rule was vacated and enjoined
nationwide. See S.C. Coastal Conservation League v. Pruitt, 318 F.
Supp. 3d 959 (D.S.C. Aug. 16, 2018); see also Puget Soundkeeper All.
v. Wheeler, No. 15-01342 (W.D. Wash. Nov. 26, 2018) (vacating the
Applicability Date Rule nationwide).
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2. The 2020 Navigable Waters Protection Rule
On January 23, 2020, the agencies signed the Navigable Waters
Protection Rule: Definition of ``Waters of the United States'' (NWPR),
a rule that for the first time defined ``waters of the United States''
based generally on the Rapanos plurality's standard. The NWPR was
published on April 21, 2020, and went into effect on June 22, 2020. 85
FR 22250 (April 21, 2020).\35\ The NWPR interpreted the term ``the
waters'' within ``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.'' Id. at 22273. Specifically, the rule
established four categories of jurisdictional waters: (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 the above three
categories of jurisdictional waters. Id. at 22273.
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\35\ The NWPR went into effect on June 22, 2020 in all States
except Colorado. 85 FR 22250 (April 21, 2020). In Colorado, the NWPR
was subject to a preliminary injunction issued by the U.S. District
Court for the District of Colorado. Colorado v. EPA, 445 F. Supp. 3d
1295 (D. Colo. 2020). The Tenth Circuit later reversed the Colorado
district court's order on appeal; as a result, the NWPR went into
effect in Colorado on April 26, 2021. Colorado v. EPA, 989 F.3d 874
(10th Cir. 2021); Colorado v. EPA, No. 20-1238, ECF No. 010110512604
(Doc. 10825032) (10th Cir. Apr. 26, 2021).
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The NWPR defined the scope of each of these four categories. The
territorial seas and traditional navigable waters were defined
consistent with the agencies' longstanding interpretations of those
terms. Id. at 22280-81. A ``tributary'' was defined 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. Id. at 22286. A jurisdictional tributary was required to be
perennial or intermittent in a typical year. Id. Additionally, the term
``tributary'' included 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. Id. at 22251. The NWPR's ``tributary'' definition did not
include ephemeral features, which were defined as surface waters that
flow only in direct response to precipitation, including ephemeral
streams, swales, gullies, rills, and pools. Id.
The NWPR defined ``lakes and ponds, and impoundments of
jurisdictional waters'' as ``standing bodies of open water that
contribute surface water flow

[[Page 52511]]

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.'' Id. at 22251. A lake,
pond, or impoundment of a jurisdictional water did not lose its
jurisdictional status if it contributes surface water flow to a
downstream jurisdictional water in a typical year through certain
artificial or natural features. Id. Under the NWPR, a lake, pond, or
impoundment of a jurisdictional water was also jurisdictional if it was
inundated by flooding from a jurisdictional water in a typical year.
Id.
As for wetlands, the NWPR interpreted ``adjacent wetlands'' to be
those wetlands that abut jurisdictional waters and those non-abutting
wetlands that are (1) ``inundated by flooding'' from a jurisdictional
water in a typical year, (2) physically separated from a jurisdictional
water only by certain natural features (e.g., a berm, bank, or dune),
or (3) physically separated from a jurisdictional water by an
artificial structure that ``allows for a direct hydrologic surface
connection'' between the wetland and the jurisdictional water in a
typical year. Id. at 22338, 22240. Wetlands that did not have these
types of connections to other waters were not jurisdictional under the
NWPR.
The NWPR's regulatory text expressly provided that waters that did
not fall into its jurisdictional categories were not considered
``waters of the United States.'' Id. at 22338. Moreover, waters within
these categories, including traditional navigable waters and the
territorial seas, were not ``waters of the United States'' if they also
fit within the NWPR's broad exclusions. See id. at 22325 (``If the
water meets any of the[ ] exclusions, the water is excluded even if the
water satisfies one or more conditions to be a [jurisdictional]
water.'').\36\ The rule excluded groundwater, including groundwater
drained through subsurface drainage systems; ephemeral features;
diffuse stormwater runoff and directional sheet flow over upland;
ditches that are not traditional navigable waters, tributaries, or that
are not constructed in adjacent wetlands, subject to certain
limitations; prior converted cropland; artificially irrigated areas;
artificial lakes and ponds; water-filled depressions constructed or
excavated in upland or in non-jurisdictional waters incidental to
mining or construction activity; 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; groundwater recharge, water reuse, and
wastewater recycling structures constructed or excavated in upland or
in non-jurisdictional waters; and waste treatment systems. Id. at
22338-39.
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\36\ The NWPR's exclusion for ditches, however, explicitly did
not encompass ditches that are traditional navigable waters or
jurisdictional tributaries. 33 CFR 328.3(b)(5) (2020).
---------------------------------------------------------------------------

Similar to other rulemakings to revise the definition of ``waters
of the United States,'' the NWPR was subject to multiple legal
challenges. On August 30, 2021, the U.S. District Court for the
District of Arizona remanded the NWPR and vacated the rule. Pascua
Yaqui Tribe v. EPA, No. 4:20-cv-00266, 2021 WL 3855977 (D. Ariz. Aug.
30, 2021). On September 27, 2021, the U.S. District Court for the
District of New Mexico also issued an order vacating and remanding the
NWPR. Navajo Nation v. Regan, No. 2:20-cv-00602 (D.N.M. Sept. 27,
2021). Six courts also remanded the NWPR without vacatur or without
addressing vacatur.\37\
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\37\ Order, Pueblo of Laguna v. Regan, No. 1:21-cv-00277, ECF
No. 40 (D.N.M. Sept. 21, 2021) (declining to reach issue of vacatur
in light of the Pascua decision); Order, California v. Wheeler, No.
3:20-cv-03005, ECF No. 271 (N.D. Cal. Sept. 16, 2021) (same);
Waterkeeper All. v. Regan, No. 3:18-cv-03521, ECF No. 125 (N.D. Cal.
Sept. 16, 2021) (same); Order, Conservation Law Found. v. EPA, No.
1:20-cv-10820, ECF No. 122 (D. Mass. Sept. 1, 2021) (same); Order,
S.C. Coastal Conservation League v. Regan, No. 2:20-cv-01687, ECF
No. 147 (D.S.C. July 15, 2021) (remanding without vacating); Order,
Murray v. Wheeler, No. 1:19-cv-01498, ECF No. 46 (N.D.N.Y. Sept. 7,
2021) (same). In this litigation, EPA and the Army had filed motions
for remand without vacatur. See, e.g., U.S. Motion for Remand
without Vacatur, Conservation Law Found. v. EPA, No. 1:20-cv-10820,
ECF No. 112 (D. Mass. June 9, 2021).
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Following vacatur of the NWPR, the agencies resumed implementing
the pre-2015 regulatory regime across the country.
3. January 2023 Rule
In January 2023, the EPA and the Army once again revised the
definition of ``waters of the United States.'' 88 FR 3004 (January 18,
2023). The 2023 Rule incorporated the two jurisdictional standards from
Rapanos into the definition of the term ``waters of the United
States.'' First, the ``relatively permanent standard'' under the 2023
Rule referred to the test to identify: relatively permanent, standing
or continuously flowing tributaries connected to traditional navigable
waters, the territorial seas, or interstate waters; relatively
permanent, standing or continuously flowing additional waters with a
continuous surface connection to such relatively permanent waters or to
traditional navigable waters, the territorial seas, or interstate
waters; and, adjacent wetlands and certain impoundments with a
continuous surface connection to such relatively permanent waters or to
traditional navigable waters, the territorial seas, or interstate
waters. See 88 FR 3006, 3038-39. Second, the ``significant nexus
standard'' under the 2023 Rule referred to the test to identify waters
that, either alone or in combination with similarly situated waters in
the region, significantly affect the chemical, physical, or biological
integrity of traditional navigable waters, the territorial seas, or
interstate waters. Id. at 3006. The regulatory text also defined
``significantly affect'' for purposes of the significant nexus
standard. Id. Under the 2023 Rule, waters were jurisdictional if they
met either standard. Id.
The 2023 Rule also defined the term ``adjacent'' with no changes
from the agencies' longstanding regulatory definition of ``adjacent''
as ``bordering, contiguous, or neighboring.'' 88 FR 3116-17. Wetlands
separated from other ``waters of the United States'' by man-made dikes
or barriers, natural river berms, beach dunes and the like were defined
as ``adjacent'' wetlands. Id.
While the 2023 Rule was not before the Supreme Court in Sackett,
the Court did review the rule's two jurisdictional standards and
concluded that the significant nexus standard was ``inconsistent with
the text and structure of the [Clean Water Act].'' 598 U.S. at 679.
4. Conforming Rule
In September 2023, EPA and the Army published a final rule amending
the 2023 Rule's definition of ``waters of the United States'' in
response to the Supreme Court decision in Sackett. ``Revised Definition
of `Waters of the United States'; Conforming,'' 88 FR 61964, 61968
(September 8, 2023) (``Conforming Rule''). The Conforming Rule
published in the Federal Register and became effective on September 8,
2023.
The Conforming Rule amended the provisions of the 2023 Rule that
were invalid under the Supreme Court's interpretation of the Clean
Water Act in Sackett. See 88 FR 61964. In particular, the agencies
revised the 2023 Rule to remove the significant nexus standard and to
amend its definition of ``adjacent'' as these provisions were rendered
invalid by Sackett. Id. at 61965-66. Per Sackett, waters are not
jurisdictional under the Clean Water Act based on the significant nexus
standard. Id. In addition, under the decision in

[[Page 52512]]

Sackett, wetlands are not defined as ``adjacent'' or jurisdictional
under the Clean Water Act solely because they are ``bordering,
contiguous, or neighboring . . . [or] separated from other `waters of
the United States' by man-made dikes or barriers, natural river berms,
beach dunes and the like.'' Id. at 61965. Therefore, waters cannot be
found to be jurisdictional because they meet the significant nexus
standard; nor can wetlands be found to be jurisdictional based on the
definition of ``adjacent'' previously codified in the 2023 Rule. Id.
Consistent with the Sackett decision, the agencies in the Conforming
Rule revised the definition of ``adjacent'' to mean ``having a
continuous surface connection.'' Id. Furthermore, because Sackett
invalidated the significant nexus standard, the agencies removed the
provision for assessment of streams and wetlands under the additional
waters provision of paragraph (a)(5) as no longer valid since any
jurisdictional streams or wetlands would fall within paragraphs (a)(1)
through (4) of the 2023 Rule.\38\ Id.
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\38\ Lakes and ponds, however, may still have been
jurisdictional under paragraph (a)(5) of the 2023 Rule if they did
not fall within paragraphs (a)(1) through (3) of the 2023 Rule (for
example, if they were not tributaries connected to waters identified
in paragraph (a)(1) or (2)) and they were relatively permanent,
standing or continuously flowing bodies of water with a continuous
surface connection to the waters identified in paragraph (a)(1) or
(3).
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Finally, the agencies removed ``interstate wetlands'' from the 2023
Rule to conform with the decision in Sackett. Id. at 61966. The Supreme
Court in Sackett examined the Clean Water Act and its statutory history
and found the predecessor statute to the Clean Water Act covered and
defined ``interstate waters'' as ``all rivers, lakes, and other waters
that flow across or form a part of State boundaries.'' 598 U.S. at 673
(citing 33 U.S.C. 1160(a), 1173(e) (1970 ed.)) (emphasis in original).
The Court concluded that the use of the term ``waters'' refers to such
``open waters'' and not wetlands. Id. As a result, under Sackett, the
provision authorizing the assertion of Clean Water Act jurisdiction
over wetlands simply because they are interstate is invalid. 88 FR
61966.
5. Current Applicable Regulatory Regimes
As noted above, the agencies refer to the regulations defining
``waters of the United States'' under the 2023 Rule, as amended by the
Conforming Rule, as the ``Amended 2023 Rule.'' The Amended 2023 Rule is
the regulatory regime that is currently codified in the Code of Federal
Regulations and that serves as the baseline for the regulatory impact
analysis for this proposal. In this action, the agencies are proposing
to revise the Amended 2023 Rule.
Due to preliminary injunctions of the Amended 2023 Rule in several
States, the agencies are implementing two regulatory regimes across the
country as of the signature date of this proposed rule.\39\ The EPA and
the Army are implementing the Amended 2023 Rule in 24 States, the
District of Columbia, and the U.S. Territories. In the other 26 States,
the agencies are interpreting ``waters of the United States''
consistent with the pre-2015 regulatory regime and the Supreme Court's
Sackett decision.\40\
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\39\ States and business groups challenged the 2023 Rule in
three courts. Two district courts preliminarily enjoined the 2023
Rule as to the plaintiff-States. Texas v. EPA, 662 F. Supp. 3d 739
(S.D. Tex. 2023); West Virginia v. EPA, 669 F. Supp. 3d 781 (D.N.D.
2023). The Eastern District of Kentucky dismissed on standing and
ripeness grounds. Kentucky v. EPA, No. 3:23-cv-7 (E.D. Ky. Mar. 31,
2023). Subsequently, the Sixth Circuit granted an injunction pending
appeal of the Eastern District of Kentucky's order to Kentucky and
business plaintiffs, which dissolved when the Sixth Circuit's
mandate issued on September 23, 2024, following the Sixth Circuit's
ruling vacating and remanding the district court's dismissal. Order,
Kentucky v. EPA, No. 23-5345, ECF No. 28 (6th Cir. May 10, 2023);
Opinion, Kentucky v. EPA, No. 23-5345, ECF No. 56-2 (6th Cir. July
29, 2024); Mandate Issued, Kentucky v. EPA, No. 23-5345, ECF No. 57
(6th Cir. Sept. 23, 2024). Kentucky then amended its complaint, and
the business plaintiffs filed a notice of voluntary dismissal.
Amended Complaint, Kentucky v. EPA, No. 3:23-cv-7, ECF No. 78 (E.D.
Ky. Nov. 8, 2024); Notice of Voluntary Dismissal, Kentucky v. EPA,
No. 3:23-cv-7, ECF No. 73 (E.D. Ky. Oct. 4, 2024). While these cases
were pending, the Supreme Court decided Sackett and the agencies
issued the Conforming Rule. After the agencies issued the Conforming
Rule, plaintiffs challenging the 2023 Rule amended their complaints
to challenge the Amended 2023 Rule and certain aspects of the
Conforming Rule and 2023 Rule. See also White v. EPA, No. 24-00013
(E.D.N.C.); White v. EPA, No. 24-1635 (4th Cir.). As of the
signature date of this proposed rule, this ongoing litigation is in
abeyance.
\40\ The latest information on the status of this litigation can
be found on the EPA's Rule Status and Litigation Update web page at
<a href="https://www.epa.gov/wotus/definition-waters-united-states-rule-status-and-litigation-update">https://www.epa.gov/wotus/definition-waters-united-states-rule-status-and-litigation-update</a>.
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6. March 12, 2025, ``Continuous Surface Connection'' Guidance
On March 12, 2025, the EPA and the Army signed a joint memorandum
to provide guidance to the agencies' field staff regarding
implementation of ``continuous surface connection'' for adjacent
wetlands. ``Memorandum to the Field between the U.S. Department of the
Army, U.S. Army Corps of Engineers and the U.S. Environmental
Protection Agency Concerning the Proper Implementation of `Continuous
Surface Connection' under the Definition of `Waters of the United
States' under the Clean Water Act'' (March 12, 2025) (``continuous
surface connection guidance''), available at <a href="https://www.epa.gov/system/files/documents/2025-03/2025cscguidance.pdf">https://www.epa.gov/system/files/documents/2025-03/2025cscguidance.pdf</a>. Consistent with
this guidance, and consistent with Sackett, the agencies are
interpreting ``continuous surface connection'' to mean abutting (or
touching) a requisite jurisdictional water. The agencies issued the
guidance in response to requests for clarification on the scope of
adjacent wetlands in light of the Supreme Court's decision in Sackett.
Specifically, the agencies had heard from a variety of co-
regulators and stakeholders that the preamble to both the 2023 Rule and
the Conforming Rule did not include adequate direction or guidance on
the meaning of the ``continuous surface connection'' requirement, and
the agencies' case-specific policy memoranda \41\ issued post-Sackett
neither provided national guidance on the topic nor clear and
transparent direction for the public or the agencies. The agencies
determined that the case-specific policy memoranda also contained
conclusions which are inconsistent with the discussion of ``continuous
surface connection'' as described in the pre-2015 regulatory regime
guidance documents and the Sackett decision.
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\41\ The agencies issued several case-specific policy memoranda
in 2024 and 2025 as part of the process in place at the time for
coordination of Corps draft AJDs. Such case-specific policy
memoranda were issued by the agencies to provide guidance to the
respective EPA regional and Corps district offices. Additional
information regarding the agencies' coordination processes is
available on EPA's website at <a href="https://www.epa.gov/wotus/coordination-process-approved-jurisdictional-determinations-and-field-memoranda">https://www.epa.gov/wotus/coordination-process-approved-jurisdictional-determinations-and-field-memoranda</a>.
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C. WOTUS Notice and Summary of Stakeholder Outreach

On March 21, 2025, the agencies signed a Federal Register document
publicizing a series of listening sessions and a 30-day recommendations
docket to solicit feedback on key aspects of the definition of ``waters
of the United States.'' ``WOTUS Notice: The Final Response to SCOTUS''
(90 FR 13428, March 24, 2025). The agencies accepted written pre-
proposal recommendations from members of the public from March 24,
2025, to April 23, 2025, which can be found in the docket (Docket ID
EPA-HQ-OW-2025-0093). The agencies held a series of stakeholder and co-
regulator listening sessions to hear pre-proposal input and
recommendations including specific meetings in March, April, May and
June of 2025 with Tribes, States and State associations, local
governments, industry, environmental organizations, agricultural
organizations, small businesses and congressional staff, and

[[Page 52513]]

two in-person public listening sessions held in communities outside of
Washington, DC. A summary of the agencies' pre-proposal listening
sessions is available in the docket (Docket ID No. EPA-HQ-OW-2025-0322)
for this proposed rule.
The Federal Register announcement outlined three key topics the
agencies were particularly interested in receiving recommendations on,
including the scope of ``relatively permanent'' waters and to what
features this phrase applies, the scope of ``continuous surface
connection'' and to which features this phrase applies, and the scope
of jurisdictional ditches. The agencies also sought input on
implementation challenges related to these key topic areas.
Additionally, the agencies engaged State and local governments in a
60-day federalism consultation period during development of this
proposed rule, beginning with an initial federalism consultation
meeting on April 3, 2025, and concluding on June 2, 2025. The agencies
also initiated a 60-day consultation period with federally recognized
Indian Tribes, beginning March 21, 2025, and concluding May 20, 2025.
Information about the federalism and Tribal consultation can be found
in sections VII.F and VII.G of this preamble, respectively, and in the
federalism and Tribal consultation reports, available in the docket
(Docket ID No. EPA-HQ-OW-2025-0322) for this proposed rule.
The agencies received input from a wide variety of Tribes, States,
local governments, environmental organizations, industry, agriculture
organizations, small businesses, and the public through virtual
meetings, consultation letters, and recommendation letters submitted to
the docket. Of the more than 45,000 recommendations received, the
docket included 48 letters from States and State associations, 25
letters from Tribes and Tribal associations, 97 letters from industry,
31 letters from agriculture organizations, 65 letters from
environmental organizations, 37 letters from local governments and
local government associations, two letters from Federal agencies, four
from other non-governmental organizations, approximately 3,900 letters
from the general public, and over a dozen mass mail campaigns. Through
the conclusion of all listening sessions, the agencies documented 228
individual verbal remarks.
The agencies received broad support for robust stakeholder outreach
and the development of a rule that is consistent with Supreme Court
precedent. Many stakeholders also emphasized the importance of regional
geographic variability across the United States, and some stakeholders
suggested the agencies consider regionally specific criteria for
jurisdictional waters. Most recommendations focused on the three key
topics for which the agencies solicited input (``relatively permanent''
waters, ``continuous surface connection,'' and ditches), as well as
consideration for implementation and further exclusions.
1. Relatively Permanent Waters
A broad range of recommendations were submitted on the scope of
``relatively permanent'' from a diverse array of stakeholder and co-
regulator groups. One common theme across most stakeholder and co-
regulator recommendations included the need for the definition to
account for regional differences in hydrologic variability across the
country. Of those who submitted recommendations, most of the States,
State associations, agriculture organizations and many industry groups
recommended that relatively permanent waters be defined as perennial
waters only, or continuously flowing year-round. Conversely, of those
who submitted recommendations, many Tribes, environmental advocacy
groups, and some industry groups recommended against further revisions
to the definition of ``waters of the United States,'' stating that the
Amended 2023 Rule accurately implements the Sackett decision. In
addition, Tribal and environmental advocacy groups broadly recommended
interpreting relatively permanent to include intermittent (including
seasonal) and perennial waters. The majority of local governments
providing feedback recommended that they and local flood control
districts be responsible for making jurisdictional determinations and
for oversight. Nearly all individual citizens providing recommendations
called for broad protection of water resources, including protecting
intermittent (including seasonal) and perennial waters. Some States and
industry supported the use of the streamflow duration assessment
methods (SDAMs) to identify relatively permanent waters and requested
the methods be available for all States.\42\ Some agriculture
organizations and industry stakeholders suggested SDAMs and ordinary
high water mark (OHWM) not be used on their own to assess jurisdiction
due in part to the implementation challenges they pose.
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\42\ Information on the SDAMs is available on EPA's website at
<a href="https://www.epa.gov/streamflow-duration-assessment">https://www.epa.gov/streamflow-duration-assessment</a>. The SDAMs are
discussed in more detail in section V.5 of this preamble.
---------------------------------------------------------------------------

2. Continuous Surface Connection
The recommendations received on the scope of ``continuous surface
connection'' focused mainly on whether discrete features such as
natural or man-made features sever continuous surface connection for
wetlands and whether wetlands separated by such features are
``abutting,'' as that term has been understood by the Supreme Court. Of
those providing feedback, most agriculture organizations, many industry
groups, some local governments, and some States recommended that
discrete features such as culverts and berms sever jurisdiction for
wetlands. Of those providing recommendations, the majority of States,
Tribes, environmental advocacy groups, some industry groups, some local
governments, and nearly all individual citizens expressed that discrete
features do not inherently sever jurisdiction. Many of those
recommendations included a call for case-by-case consideration of
seasonal dry period variations as well as precipitation-driven
connectivity, whether the continuous surface connection has
characteristics of a relatively permanent water, and evidence of a
continuous surface connection. Individual citizens providing
recommendations generally called for an inclusive interpretation of
continuous surface connection, asserting that all water has
connectivity, even in dry periods. Many recommendations from
environmental advocacy stakeholders cited or broadly discussed
connectivity, including the EPA's 2015 Connectivity Report.\43\
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\43\ U.S. EPA. Connectivity of Streams and Wetlands to
Downstream Waters: A Review and Synthesis of the Scientific Evidence
(Final Report). U.S. Environmental Protection Agency, Washington,
DC, EPA/600/R-14/475F, 2015. Available at <a href="https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=296414">https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=296414</a>.
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3. Ditches
The recommendations received on ditches focused on whether ditches
should be excluded from the definition of ``waters of the United
States'' and whether the function of the ditch should be considered in
identifying excluded ditches. Of those providing feedback, agriculture
organizations, some industry stakeholders, some local governments, and
a few States recommended excluding all ditches from the definition of
``waters of the United States.'' On the other hand, of those providing
feedback, most States, State associations, Tribes, some environmental
advocacy groups,

[[Page 52514]]

several local governments, and some industry stakeholders recommended
that ditches that function as natural, relatively permanent features
should be jurisdictional. Many of these recommendations also stated
that ditches excavated only in uplands or non-jurisdictional waters and
ditches that have no more than ephemeral flow should be excluded. Many
local governments and agriculture organizations providing
recommendations showed support for the 2020 Ditch Exemption Memo,\44\
though they recommended limited revisions to clarify the Clean Water
Act section 404(f) exemptions for construction or maintenance of
irrigation ditches and maintenance of drainage ditches.
---------------------------------------------------------------------------

\44\ <a href="https://www.epa.gov/sites/default/files/2020-07/documents/final_ditch_exemption_memo_july_2020_with_epa.pdf">https://www.epa.gov/sites/default/files/2020-07/documents/final_ditch_exemption_memo_july_2020_with_epa.pdf</a>.
---------------------------------------------------------------------------

4. Implementation
A wide variety of recommendations on the definition of ``waters of
the United States'' and on Clean Water Act program process and
implementation fell outside of the three key definition topics,
including: (1) encouraging more voluntary incentives for landowners to
protect wetlands, (2) offering compensatory mitigation solutions such
as streamlining the mitigation bank review and approval process, (3)
improving the process for obtaining a U.S. Department of Agriculture
(USDA) determination for prior converted cropland, (4) updating
training for field staff and developing regional guidance, (5) creating
maps and tools to determine ``waters of the United States,'' and (6)
including Tribes and States in further Federal rulemaking development.
5. Additional Feedback Including Further Exclusions
Some States recommended that the intrastate waters category (e.g.,
paragraph (a)(5) of the Amended 2023 Rule) not be included as a
separate basis of jurisdiction. Stakeholders and co-regulators
expressed different views about which exclusions should be included in
a revised definition of ``waters of the United States.'' Many States
recommended excluding certain water features such as permafrost
wetlands, ephemeral waters that only periodically provide drainage for
rainfall or conveyances for irrigation water, isolated and artificial
ponds, and excluding wetlands generally unless they qualify as waters
on their own. Many stakeholders expressed support for the waste
treatment system exclusion and prior converted cropland exclusions.
Some stakeholders expressed support for adding other exclusions, such
as an exclusion for groundwater and an exclusion for stormwater control
features that do not exhibit continuous surface water flow to navigable
waters. Some industry stakeholders recommended excluding features
specific to mining operations until such time as they are reclaimed as
part of a created or enhanced wetlands complex.
The agencies have thoroughly reviewed and considered the
recommendations received for purposes of developing the proposed
rulemaking. The agencies welcome feedback on this proposed rule through
one of the upcoming public meetings and the 45-day public comment
period initiated through publication of this action, as discussed in
section II of this preamble. The agencies will consider all comments
received during the comment period on this proposal during the
development of the final rule and supporting documents.

V. Proposed Revised Definition

A. Basis of the Proposed Rule

The agencies are proposing to amend certain portions of the Amended
2023 Rule, as discussed below, with amendments to reflect the agencies'
determination of the statutory limits on the scope of the ``waters of
the United States'' consistent with, and informed by, Supreme Court
precedent. Section I.B of this preamble contains a summary of the
agencies' proposed revisions. All other aspects of the agencies'
regulations defining ``waters of the United States'' would remain
unchanged. Under the agencies' proposed rule, the term ``waters of the
United States'' would include (1) traditional navigable waters and the
territorial seas; (2) most impoundments of ``waters of the United
States;'' (3) relatively permanent tributaries of traditional navigable
waters, the territorial seas, and impoundments; (4) wetlands adjacent
(i.e., having a continuous surface connection) to traditional navigable
waters, impoundments, and tributaries; and (5) lakes and ponds that are
relatively permanent and have a continuous surface connection to a
traditional navigable water, the territorial seas, or a tributary. The
agencies are also proposing to amend the exclusions for waste treatment
systems, prior converted cropland, and certain ditches, and to add an
exclusion for groundwater. Finally, the agencies are proposing to add
definitions for ``continuous surface connection,'' ``ditch,'' ``prior
converted cropland,'' ``relatively permanent,'' ``tributary,'' and
``waste treatment system.''
The proposed rule reflects the balance Congress struck between the
Clean Water Act section 101(a) statutory objective to ``restore and
maintain the chemical, physical, and biological integrity of the
Nation's waters,'' and the policy in Clean Water Act 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(a) and (b). In developing an appropriate regulatory
framework for the proposed rule, the agencies recognize and respect the
primary responsibilities and rights of States to regulate their land
and water resources. Id. 1251(b), see also id. 1370. The oft-quoted
objective of the Clean Water Act at 101(a) must be implemented in a
manner consistent with Congress' 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.'' Daniel Ball, 77 U.S. (10 Wall.) at 557.
Over a century later, the Supreme Court in SWANCC reaffirmed ``the
States' 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 opinion). And in Sackett, the Supreme Court confirmed that
the balance between State and Federal authority embodied in the Act
cannot be redrawn in response to ecological concerns. 598 U.S. at 683.
While Clean Water Act 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 proposed 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 Clean Water Act and ensures that
the agencies are giving full effect and consideration to the entire
structure and function of the Act. See, e.g., Sackett, 598 U.S. at 674
(``It is hard to see how the States' role in regulating water resources
would remain `primary' if the EPA had jurisdiction over anything
defined by the presence of water.''); Rapanos, 547

[[Page 52515]]

U.S. at 755-56 (Scalia, J., plurality opinion) (``[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 Clean Water Act 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., Rapanos, 547 U.S. 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.''). Including all of the Nation's waters
within 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 Clean Water Act and the
specific policy directives from Congress, the agencies would 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 519, 544 (2012).
The proposed rule is also consistent with and informed by the
Supreme Court's seminal decision in Sackett. In developing the proposed
rule, the agencies considered the text and structure of the statute,
other relevant precedents, and the agencies' experience and expertise
implementing the definition of ``waters of the United States.'' The
limitations in the proposed rule both reflect consideration of the
comprehensive nature and objective of the Clean Water Act and avoid
assertions of jurisdiction that exceed the agencies' statutory
authority or raise federalism concerns. The Sackett decision clarifies
where the agencies draw the boundaries of Federal jurisdiction in
keeping with Congress's objective while preserving and protecting the
responsibilities and rights of the States, as Congress recognized in
the Clean Water Act. The proposed rule's limitations conform with the
Sackett decision and thereby ensure that Clean Water Act regulatory
programs will apply where waters meet the definition of ``waters of the
United States.'' States and Tribes have authority to regulate waters
that do not meet the proposed rule's definition of ``waters of the
United States'' as they deem appropriate. Finally, the proposed rule
would also achieve the agencies' goals of ensuring clarity, simplicity,
and improvements that will stand the test of time, while providing for
durable, stable, and more effective and efficient jurisdictional
determinations and permitting actions.
The Regulatory Impact Analysis for the Proposed Rule provides
information about the potential differences between current
implementation and the proposed rule. The assessment can be found in
the docket for this proposed action.
When preparing an approved jurisdictional determination,\45\ which
is typically made at the request of a landowner or applicant, the
agencies bear the burden of proof in demonstrating that an aquatic
resource meets the requirements under the proposed rule to be
jurisdictional or excluded. The agencies' jurisdictional determinations
must adequately document the basis of jurisdiction--that is, summarize
the indicators that support the determination such as the information
that demonstrates that the waters, including any wetlands, at issue
meet the requirements of paragraphs (a) or (b) of the proposed rule, as
applicable. Under any definition of ``waters of the United States,''
the agencies will rely on a weight of evidence approach when
determining whether a water meets the regulatory requirements for
asserting Federal jurisdiction. This means that if the agencies do not
have adequate information to demonstrate that a water meets the
jurisdictional standards to be a ``water of the United States,'' the
agencies would find such a water to be non-jurisdictional. The agencies
invite comment on approaches for increasing predictability in
jurisdictional determinations, including options for leveraging data
and tools discussed infra in section V of this preamble and in section
3 of the Regulatory Impact Analysis for the Proposed Rule.
---------------------------------------------------------------------------

\45\ For convenience, EPA decisions on jurisdiction are referred
to as jurisdictional determinations throughout this document, but
such decisions are not ``approved jurisdictional determinations'' as
defined and governed by the Corps' regulations at 33 CFR 331.2.
Approved jurisdictional determinations are typically made at the
request of a landowner or applicant. See, e.g., Regulatory Guidance
Letter (RGL) 16-01, available at <a href="https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll9/id/1256">https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll9/id/1256</a>.
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This proposal does not propose to change the scope of paragraph
(a)(1)(i), addressing traditional navigable waters. However, the
agencies are considering whether clarifications to the scope of that
provision may be warranted in the final rule preamble or in a separate
administrative action. Specifically, the agencies are considering
whether it may be necessary to elucidate what it means for a water to
be ``susceptible to use in interstate or foreign commerce.'' The
agencies welcome comments from members of the public about any
experiences they may have had with findings that waters are
``susceptible to use in interstate or foreign commerce,'' any concerns
they may have with current or potential future implementation of that
provision, or other aspects of this provision that may warrant
additional clarification or interpretation by the agencies. In
addition, the agencies solicit input on whether the agencies should
reinstate the joint agency coordination memorandum issued on June 30,
2020, requiring elevation of certain traditional navigable waters
determinations (See U.S. Environmental Protection Agency (EPA) and U.S.
Army Corps of Engineers (Corps) Process for Elevating and Coordinating
Specific Draft Determinations under the Clean Water Act (CWA),
available in the docket for this proposed rule).
The agencies also solicit comment on an alternative approach to the
proposed rule, whereby ``waters of the United States'' would encompass
traditional navigable waters, tributaries that directly flow into these
waters, and wetlands with a continuous surface water connection to such
waters. All other waters would be excluded. This alternative is
informed by Justice Thomas's concurring opinion in Sackett, which
emphasized that ``the term `navigable waters' refers solely to the
aquatic channels of interstate commerce over which Congress
traditionally exercised authority.'' 598 U.S. at 697 (Thomas, J.,
concurring). The agencies seek comment on whether the statute and the
relevant history of Federal authority over navigable waters support
this approach, or whether they support the agencies' proposal to
include a broader category of tributaries and adjacent wetlands within
the scope of ``navigable waters,'' based on the plain meaning of the
term ``waters'' (informed by the qualifier ``navigable'') and the
continuous surface connection between such waters and wetlands.

[[Page 52516]]

B. Interstate Waters

The proposed rule would remove the category of interstate waters
from the definition of ``waters of the United States.'' Because this
category can encompass bodies of water that are not relatively
permanent, standing, or continuously flowing or that are not themselves
connected to a downstream traditional navigable water or the
territorial seas, either directly or through one or more waters or
features that convey relatively permanent flow, its removal would
ensure consistency with the Sackett decision as well as the Clean Water
Act. This approach would also address persistent litigation over this
category. Under the proposal, interstate waters would only be ``waters
of the United States'' if they fall within another jurisdictional
category in the definition. The change would likely have few practical
impacts and would not undermine significant reliance interests, as the
agencies rarely identify waters as jurisdictional solely because they
are interstate as they often fall under one of the other categories of
``waters of the United States'' (e.g., the waters are also traditional
navigable waters or jurisdictional tributaries). Based on an analysis
of data associated with approved jurisdictional determinations
finalized by the Corps between August 28, 2015, and September 18, 2025,
a total of 15 waters were found to be jurisdictional as interstate
waters during that time frame. Under the proposed rule, rivers like the
Amargosa River, which flows from Nevada into a dry playa in Death
Valley, California, would not be jurisdictional simply because they
cross a state boundary. Rather, these rivers would only be covered by
Federal jurisdiction if they are themselves jurisdictional by some
other means, such as being traditional navigable waters or
jurisdictional tributaries.
The agencies previously eliminated the category of interstate
wetlands from the interstate waters category in the Conforming Rule,
see 88 FR 69166-69169 (September 8, 2023), meaning that the proposed
rule's elimination of the interstate waters category water by itself
would not impact the jurisdictional status of interstate wetlands like
the Great Dismal Swamp, which crosses the border between Virginia and
North Carolina--under both current implementation and the proposed
rule, such wetlands are only jurisdictional if they meet another
category of ``waters of the United States'' (e.g., wetlands subject to
the ebb and flow of the tide or adjacent wetlands).
Given the proposed deletion of the (a)(1)(iii) interstate waters
category, the agencies are also proposing a ministerial change to
paragraph (a) to add an ``or'' after the (a)(1)(i) category and delete
the ``or'' after the (a)(1)(ii) category. This revision would be
necessary as there would be only two remaining water types under
category (a)(1) with the proposed deletion of interstate waters. The
agencies are not proposing any other changes to the (a)(1)(i) or (ii)
categories.
1. Basis for Eliminating as an Independent Basis for Jurisdiction
Removing the category of ``interstate waters'' as an independent
basis for jurisdiction reflects the language of the Clean Water Act, as
interpreted by the Supreme Court, as well as the history of the Act and
Congress' authority under the Constitution to regulate ``waters of the
United States.'' The Supreme Court has interpreted ``waters'' in the
context of the Clean Water Act to encompass ``only those relatively
permanent, standing or continuously flowing bodies of water `forming
geographic[al] features' that are described in ordinary parlance as
`streams, oceans, rivers, and lakes.' '' Sackett, 598 U.S. at 671
(citing Rapanos, 547 U.S. at 739 (plurality opinion)). Specifically
with respect to ``waters of the United States,'' the Sackett Court held
that a ``water of the United States'' must be ``a relatively permanent
body of water connected to traditional interstate navigable waters'' or
``wetland[s] [with] a continuous surface connection with that water.''
Id. at 678 (citing Rapanos, 547 U.S. at 742, 755); see section IV.A of
this preamble. Nothing in Sackett or the Rapanos plurality opinion
suggests that Congress intended to separately regulate interstate
waters that do not meet this test.
As discussed in section IV.A of this preamble, the Court has made
clear that Congress' authority for enacting the Clean Water Act is
derived from ``[i]ts 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. The Court explained in SWANCC that nothing in
the legislative history of the Clean Water Act Amendments ``signifies
that Congress intended to exert anything more than its commerce power
over navigation.'' Id. at 168 n.3. The scope of the agencies'
regulation must therefore reflect the limits imposed by the term,
``navigable waters.'' The agencies propose that regulating all
interstate waters--from isolated ponds to ephemeral washes--regardless
of their connection to navigability would impermissibly ``read[ ] the
term `navigable waters' out of the statute.'' See id. at 172.
The history of the Clean Water Act supports the agencies' proposed
removal of the category of interstate waters. The original Water
Pollution Control Act (WPCA) of 1948 regulated the ``pollution of
interstate waters,'' defined as ``all rivers, lakes, and other waters
that flow across, or form a part of, State boundaries.'' WPCA of 1948,
2(d)(1), (4), 10(e), 62 Stat. 1155, 1156-57, 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 the 1972 Amendments,
however, establishing the current statutory structure, Congress
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). Congress
specifically did not carry the term ``interstate waters'' forward as
the operative phrase for Federal jurisdiction. Following basic canons
of statutory construction, the agencies now interpret Congress' removal
of the term ``interstate waters'' as intentional. 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.'').
Congress' removal of the prior term, ``interstate waters,'' and its
replacement of that term with ``navigable waters,'' supports the
agencies' view that interstate waters can only be jurisdictional if
they have the requisite connection to traditional navigable waters and
fall within the Supreme Court's interpretation of ``waters of the
United States.'' After considering Congress' constitutional authority
over navigable waters that forms the basis for Clean Water Act
jurisdiction (see section IV.A of this preamble), the Supreme Court's
interpretation of the term ``waters of the United States,'' and the
history of the statute, the agencies

[[Page 52517]]

are proposing that only those interstate waters that would fall within
another category in this proposed rule are jurisdictional. Other
interstate waters fall beyond the agencies' authority under the Clean
Water Act and are more appropriately regulated by the States and Tribes
under their sovereign authorities.
The agencies evaluated their longstanding interpretation prior to
2020, and reinstated in 2023, which included interstate waters as a
standalone jurisdictional category (though the agencies clarified that
``waters of the United States'' does not include ``interstate
wetlands'' in the Conforming Rule following Sackett). 88 FR 61966. As
discussed in section IV.B of this preamble above, the EPA promulgated
its first regulatory definition for the term ``navigable waters'' in
1973. 38 FR 13528 (May 22, 1973). In that regulation, the EPA
established ``interstate waters'' as a separate category of ``waters of
the United States,'' distinct from the traditional navigable waters
category, retained it as such until 2020, and restored it in 2023. The
agencies are now proposing that the best interpretation of ``waters of
the United States'' is that it only encompasses those interstate waters
that meet the jurisdictional test laid out by the Supreme Court in
Sackett and the Rapanos plurality opinion. As noted above, the agencies
are not proposing any other changes to the (a)(1)(i) or (ii)
categories.
In support of their prior interpretation, the agencies have argued
that the term ``waters of the United States'' unambiguously covers
``interstate waters.'' The agencies have asserted that ``interstate
waters'' are waters of the several States and, thus, the United States.
However, the agencies now recognize that nothing in the Rapanos
plurality or Sackett opinions provides a basis for interpreting
interstate waters as jurisdictional if they are not themselves
traditional navigable waters or the territorial seas, relatively
permanent tributaries of traditional navigable waters or the
territorial seas, wetlands with a continuous surface connection to
these waters, or impoundments of otherwise jurisdictional waters.
The agencies have referred to section 303(a) of the Clean Water Act
as further textual evidence that Congress intended ``interstate
waters'' to be retained as an independent category of jurisdictional
waters. That provision authorizes water quality standards for
``interstate waters'' developed following the 1965 amendments to remain
in effect, subject to revision under the new statutory program. 33
U.S.C. 1313(a). Yet the legislative history of the 1972 amendments
indicates that Congress did not consider interstate waters and
navigable waters to be two distinct categories; rather, they 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 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). In light of this history,
the section 303(a) provision relating to existing water quality
standards for ``interstate waters'' may be best understood as referring
to ``interstate navigable waters,'' rather than any interstate waters
regardless of their connection to traditional navigable waters.
The agencies 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 support their prior interpretation. Yet neither case addressed the
specific question of whether ``interstate waters'' and ``navigable
waters'' are separate categories of jurisdictional waters under the
Clean Water Act. They instead addressed interstate water pollution
generally, and the water at issue in those cases was Lake Michigan, a
water that is both interstate and navigable. The 1972 case, which was
decided prior to the 1972 Federal Water Pollution Control Act
amendments, refers 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). However, the 1981
decision refers to the 1972 Amendments 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 Federal Water Pollution Control Act
amendments). While Milwaukee refers to the 1972 Amendments of the
Federal Water Pollution Control Act as affecting ``interstate waters,''
its language generally supports the agencies' interpretation that prior
iterations of the statute referring to both interstate waters and
navigable waters were replaced with a completely new program in 1972.
The agencies therefore no longer find these cases a persuasive basis
for regulating ``interstate waters'' as a distinct category of ``waters
of the United States.''
The proposed rule's approach to interstate waters is consistent
with a district court decision that ruled on a motion for summary
judgment on this issue following SWANCC and Rapanos. In Georgia v.
Wheeler, the court directly addressed the 2015 Clean Water Rule's
assertion of authority over all interstate waters, including
nonnavigable interstate waters. 418 F. Supp. 3d 1336, 1358-59 (S.D. Ga.
2019). The court noted that under that rule, ``a mere trickle, an
isolated pond, or some other small, non-navigable body of water would
be under federal jurisdiction simply because it crosses a state line or
lies along a state border.'' Id. at 1359. The court concluded that
``the inclusion of all interstate waters,'' including those with
``little or no connection to navigable-in-fact waters,'' exceeds the
agencies' authority under the Clean Water Act, as discussed in SWANCC.
Id. The agencies find persuasive the court's analysis and conclusion in
Georgia v. Wheeler.

C. Relatively Permanent Waters

1. Definition and Scope of ``Relatively Permanent'' Waters
In this proposal, the agencies define ``relatively permanent'' to
mean ``standing or continuously flowing bodies of surface water that
are standing or continuously flowing year-round or at least during the
wet season.'' Consistent with the Sackett decision, ephemeral waters
(i.e., those with surface water flowing or standing only in direct
response to precipitation (e.g.,

[[Page 52518]]

rain or snow fall)) are not jurisdictional because they are not
relatively permanent. The phrase ``at least during the wet season'' is
intended to include extended periods of predictable, continuous surface
hydrology occurring in the same geographic feature year after year in
response to the wet season, such as when average monthly precipitation
exceeds average monthly evapotranspiration. As proposed, surface
hydrology would be required to be continuous throughout the entirety of
the wet season. The temporal component for wet season is intended to be
an extended period where there is continuous surface hydrology
resulting from predictable seasonal precipitation patterns year after
year. The agencies acknowledge that surface hydrology may not always
exactly overlap with the wet season, for example in regions exhibiting
a time lag or delay in demonstration of surface hydrology due to
various factors. The latter may occur, for example, as a result of
snowpack melt occurring several months after repeated snowfall creates
a snowpack. In another example, some streams experience delayed (i.e.,
lagged) surface hydrology during the transition from the dry season to
the wet season, as it may take some time for the water table to rise
due to seasonal precipitation patterns.
Under the proposed rule, ``relatively permanent'' applies to both
tributaries under paragraph (a)(3) and lakes and ponds under paragraph
(a)(5). The proposed definition of ``relatively permanent'' would also
apply to determining when wetlands are adjacent to impoundments that
are relatively permanent, standing or continuous flowing bodies of
water. See section V.C.5.a of this preamble for additional information
about implementation of ``relatively permanent.'' In light of the
Sackett decision, the agencies solicit comment on the definition of
``relatively permanent'' in this proposed rule, including
implementation of the definition and regional implications of the
proposed approach.
2. Basis for the Proposed Definition
This proposed definition is based on the text of the Clean Water
Act and recent Supreme Court decisions interpreting the term ``waters
of the United States,'' as well as the agencies' expertise and desire
to establish a clear and easily implementable definition. As discussed
in section IV.A of this preamble, the plurality opinion in Rapanos
interpreted the term ``waters of the United States'' as covering
``relatively permanent, standing or continuously flowing bodies of
water'' that are connected to traditional navigable waters, as well as
wetlands with a ``continuous surface connection'' to such waterbodies.
547 U.S. at 739, 742 (Scalia, J., plurality opinion). The Rapanos
plurality 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 Sackett, the Supreme Court concluded that the Rapanos plurality
was ``correct'' in interpreting ``waters of the United States'' (for
purposes of surface waters, as opposed to wetlands) as ``encompassing
`only those relatively permanent, standing or continuously flowing
bodies of water forming geographic[al] features that are described in
ordinary parlance as streams, oceans, rivers, and lakes.' '' 598 U.S.
at 671 (quoting Rapanos, 547 U.S. at 739).
The agencies' proposed definition of ``relatively permanent''
implements the Court's interpretation of ``waters of the United
States'' in the Rapanos plurality decision, adopted by the majority in
Sackett, in an understandable and implementable way for both ordinary
citizens and expertly trained scientists. It is faithful to the Rapanos
plurality opinion and the Sackett decision because bodies of water that
have standing or flowing surface water year-round are, by definition,
permanent. And while the Rapanos plurality noted that waters of the
United States do not include ``ordinarily dry channels through which
water occasionally or intermittently flows,'' 547 U.S. at 733, it 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. The proposed definition of ``relatively permanent''
includes water features that are standing or flowing continuously ``at
least during the wet season,'' which is consistent with the plain
meaning of ``waters,'' ``lakes'' and ``streams'' and with the Rapanos
plurality's intent to avoid excluding seasonal waters. The Sackett
decision adopted the Rapanos plurality's interpretation of ``relatively
permanent,'' 598 U.S. at 671, although the agencies acknowledge that
the Sackett decision did not specifically address the reference to
seasonal waters in the Rapanos plurality. Having standing or continuous
flow at least during the wet season most typically occurs in surface
waters at the same time each year; for example, during times when
groundwater tables are elevated or when snowpack runoff produces
relatively permanent flow, returning on an annual basis during the wet
season in known, fixed geographic locations. The proposed definition is
thus consistent with the Rapanos plurality's concepts of ``relatively
permanent,'' as explicitly endorsed by the Sackett decision, and
``seasonal,'' while not capturing features that are ephemeral.
Moreover, while excluding features that lack flow during the wet
season, the agencies are implementing Clean Water Act section 101(b),
which ``protect[s] 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); see also Sackett, 598 U.S. at 674 (``It is hard to see how the
States' role in regulating water resources would remain ``primary'' if
the EPA had jurisdiction over anything defined by the presence of
water.'') 33 U.S.C. 1251(b); see also Sackett, 598 U.S. at 674 (``It is
hard to see how the States' role in regulating water resources would
remain ``primary'' if the EPA had jurisdiction over anything defined by
the presence of water.'')
Finally, the proposed definition incorporates terms that are easily
understood in ordinary parlance and should be implementable by both
ordinary citizens and trained professionals. In a similar way,
scientists, environmental consultants, and other water resource
professionals, including the agencies' staff, have used the concept of
the ``wet season'' for decades to assess water features--including to
assess if observations made during a site visit or through
interpretation of aerial photography are made under normal, wetter than
normal, or drier than normal climatic conditions, and to assist with
delineating wetlands--and the concept of a body of surface water that
is standing or continuously flowing year-round has been a part of the
relatively permanent standard since the Rapanos guidance. Indeed, the
agencies apply the concept of ``wet season'' in the use of the Corps'
Antecedent Precipitation Tool (APT),\46\ which is routinely used to
inform wetland delineations and jurisdictional determinations.\47\ See

[[Page 52519]]

section V.C.5.b of this preamble for further discussion of
implementation of ``relatively permanent.'' The agencies intend to use
the metrics from the Web-based Water-Budget Interactive Modeling
Program (WebWIMP), which are reported in the APT, as a primary source
for identifying the wet season.\48\ The agencies also believe that the
incorporation of wet season into the proposed definition of
``relatively permanent'' can be viewed as a bright line test, as it
would provide a required duration threshold for which a water must have
standing or flowing water in order to be considered jurisdictional.
Unlike typical bright line approaches, however, the agencies' proposed
approach would also allow for regional variation given the range of
hydrology and precipitation throughout the country. The line the
agencies propose to draw between relatively permanent and non-
relatively permanent waters enhances administrative efficiency and
reflects a balancing of the law, common sense, science, and stakeholder
input received pre-proposal.
---------------------------------------------------------------------------

\46\ Available at <a href="https://github.com/erdc/Antecedent-Precipitation-Tool/releases">https://github.com/erdc/Antecedent-Precipitation-Tool/releases</a>.
\47\ Sparrow, K.H., Brown, SW, French, C.E., Gutenson, J.L.,
Hamilton, C.O., and Deters, J.C. 2025. Antecedent Precipitation Tool
(APT) Version 3.0: Technical and User Guide. U.S. Army Corps of
Engineers. ERDC/TN WRAP-25-1. Available at <a href="https://erdc-library.erdc.dren.mil/items/af14290c-ed08-411b-ae5d-effa5b5b947d">https://erdc-library.erdc.dren.mil/items/af14290c-ed08-411b-ae5d-effa5b5b947d</a>.
\48\ The APT reports an interpretation of the average monthly
water-balance metrics from WebWIMP (available at <a href="http://cyclops.deos.udel.edu/wimp/public_html/index.html">http://cyclops.deos.udel.edu/wimp/public_html/index.html</a>), as an estimation
of the approximate dates of the wet and dry seasons for the
observation location, including whether the date of observation
falls within the wet season or the dry season. The interpretation of
wet season using the results from WebWIMP is that the wet season
corresponds to all periods of the year where precipitation is
estimated to, on average, exceed evapotranspiration. See
``Additional Information on the Antecedent Precipitation Tool
(APT),'' available at <a href="https://www.epa.gov/system/files/documents/2022-12/Additional%20Information%20on%20the%20APT.pdf">https://www.epa.gov/system/files/documents/2022-12/Additional%20Information%20on%20the%20APT.pdf</a>.
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3. Alternative Approaches
The agencies considered proposing to limit the definition of
``relatively permanent waters'' to only ``perennial'' waters and
solicit public comment as to whether the agencies should adopt this
alternative definition. The agencies evaluated this interpretation
because ``perennial'' streams are most obviously ``permanent,''
consistent with the Sackett decision and the Rapanos plurality opinion.
The agencies are not proposing this approach, however, because the term
``relatively'' in Sackett and the Rapanos plurality suggests that Clean
Water Act jurisdiction may not be limited to waters that are standing
or continuously flowing every day or that always have standing water.
Moreover, limiting the scope of relatively permanent waters to
perennial streams would exclude waters that the Rapanos plurality
stated are ``not necessarily exclude[d]'' (emphasis added): ``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.'' 547
U.S. at 732 n.5 (emphasis in original); see also Sackett, 598 U.S. at
651, 671 (``we conclude that the Rapanos plurality was correct.'').
While this approach would exclude the ``seasonal'' streams that the
Rapanos plurality may have not necessarily intended to exclude, the
absence of an explicit reference to such ``seasonal'' streams in
Sackett could be interpreted to mean that Sackett defined the scope of
``relatively permanent'' to exclude such water features.
Perennial streams are common in wetter parts of the country but are
rare in the arid West, so this approach may result in Federal
regulatory jurisdiction over a greater proportion of water bodies in
certain parts of the country compared to other regions. However, as an
implementation matter, limiting ``relatively permanent'' waters to
``perennial'' features may simplify implementation of the rule. If
members of the public see that waters dry up on a regular basis other
than in times of drought, they would know those waters are not
jurisdictional simply by observation, without the need for any further
analysis or professional consultation. However, it may be more
challenging to identify whether a stream flows year-round or a few days
less than year-round. Such methods or the use of remote tools may
require repeated or continuous monitoring over the course of a year or
longer to ensure water is standing or flowing year-round. In addition,
stream assessment methods are sometimes more accurate in identifying
streams with at least seasonal flow (~82-95% accuracy) than identifying
streams with perennial flow (~75-91% accuracy), as indicators are more
readily identifiable between seasonal streams and those that only flow
in direct response to precipitation.\49\ The agencies solicit comment
as to whether ``relatively permanent'' should be limited to perennial
waters or should otherwise be defined differently than what the
agencies propose here. The agencies also solicit comment on whether the
extent of the agencies' interpretation of ``wet season'' appropriately
aligns with the Rapanos plurality's discussion of ``seasonal rivers'',
or whether the agencies should interpret ``wet season'' to reflect a
flow duration that is more than during the wet season but less than
perennial flow.
---------------------------------------------------------------------------

\49\ See, e.g., James, A., McCune, K., Mazor, R. 2021. Review of
Flow Duration Methods and Indicators of Flow Duration in the
Scientific Literature, Northeast and Southeast of the United States.
Document No. EPA-840-B-22007. Available at <a href="https://www.epa.gov/system/files/documents/2023-05/Literature-Review-Beta-SDAM-NE-and-SE.pdf">https://www.epa.gov/system/files/documents/2023-05/Literature-Review-Beta-SDAM-NE-and-SE.pdf</a>.
---------------------------------------------------------------------------

The agencies also considered an approach that would set certain
minimum flow volume thresholds in the proposed definition of
``relatively permanent.'' The proposed definition of ``relatively
permanent'' does not establish bright line requirements, such as for a
particular flow volume. In 1977, the Corps proposed to use flow volumes
(i.e., normally less than 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 a 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 the proposed
approach to ``relatively permanent'' may also be supported by field
measurements, remote tools may also be used to observe presence or
absence of flow and identify flow during the wet season. Those remote
tools can assess flow frequency, and some can provide flow volume
estimates.\50\ In addition, the agencies have not identified a
rationale for a threshold of specific flow volumes that would establish
jurisdiction given the broad nationwide applicability of the proposed
rule and the regional variability in flow volumes.
---------------------------------------------------------------------------

\50\ See USGS Enhanced Runoff Method, or EROM, used to compute
estimates of the mean annual flow for the National Hydrography
Dataset (NHD) Plus flowline features in the NHDPlus High Resolution
network. See also USGS Dynamic Surface Water Extent (DSWE).
Available at: <a href="https://www.usgs.gov/landsat-missions/landsat-dynamic-surface-water-extent-science-products">https://www.usgs.gov/landsat-missions/landsat-dynamic-surface-water-extent-science-products</a>.
---------------------------------------------------------------------------

Additionally, the agencies considered, but are not proposing, a
minimum flow duration metric (e.g., 30, 90, or 270 days \51\) or bright
lines set by region, e.g., by requiring flow a minimum of 270 days east
of the Mississippi River and a minimum of 30 or 60 days west of the
Mississippi, for relatively permanent waters. One such bright line
approach would not rely on the proposed wet season approach but could
require a minimum 90-day flow duration requirement to be consistent
with what

[[Page 52520]]

is generally considered a ``season'' (i.e., with each of the four
``seasons'' lasting three months of the year) or a 270-day flow
duration requirement to exclude the driest of seasons. This bright line
approach would provide transparency and regulatory certainty for
landowners and is easy to understand. This alternative approach would
also provide a strict threshold cutoff for establishing jurisdiction.
The proposed definition considers streamflow duration in the flow
classification definitions generally (e.g., ``flowing continuously
year-round,'' ``flowing continuously during the wet season'') but
without specifying an exact number of days of flow. The time period
that encompasses flow during the wet season can vary across the country
based upon climate, hydrology, topography, soils, and other conditions.
While establishing a minimum duration of flow could ultimately enhance
national consistency per the regulatory text, it would likely be
inconsistent with the regionalized implementation of relatively
permanent tributaries in the proposed rule. For example, streams with
continuous flow during the wet season in the arid West are
fundamentally different from such streams in the Southeast. Similar to
identifying flow duration year-round, a bright line for minimum flow
durations can pose implementation challenges to identify that flow has
occurred for that exact duration threshold--even landowners familiar
with their properties may not know the exact number of days a stream
flows per year. However, the agencies acknowledge there are benefits to
setting bright lines as they can provide clarity to stakeholders and
may provide additional transparency on the requirements for flow
duration of relatively permanent waters without the use of additional
tools; therefore, the agencies solicit comment and would welcome any
supporting rationales for particular thresholds that take into account
the broad nationwide applicability of the proposed rule, as well as
address any implementation challenges, in particular related to the
minimum 90-day or 270-day flow duration requirement under this
alternative approach and whether and how continuous flow could be
identified under such a regime. This same alternative approach could
also be applied to the ``continuous surface connection'' definition,
where surface water inundation would be required for at least 90 days
or 270 days as opposed to ``surface water at least during the wet
season,'' as proposed. See section V.D.3 of this preamble for a similar
discussion on this alternative approach for continuous surface
connection.
---------------------------------------------------------------------------

\51\ Rapanos, 547 U.S. at 739, n.5 (``By describing `waters' as
`relatively permanent,' we do not necessarily exclude streams,
rivers, or lakes that might dry up in extraordinary circumstances,
such as drought. We also do not necessarily exclude seasonal rivers,
which contain continuous flow during some months of the year but no
flow during dry months.'').
---------------------------------------------------------------------------

Furthermore, the agencies are not proposing to define ``relatively
permanent'' using only physical indicators of flow, such as with a
requirement for an ordinary high water mark and bed and banks. For
purposes of implementation of the proposed rule, ``bed and banks''
means the substrate and sides of a channel, lake, or pond between which
standing water or continuous flow is ordinarily confined, as discussed
further in section V.5 of this preamble. Though the agencies consider
indicators of flow to be appropriate for defining ``tributary,'' as
discussed further below in section V.C.4 of this preamble, the agencies
propose that physical indicators of flow would be inadequate to define
relatively permanent because streams that flow only in direct response
to precipitation, such as ephemeral streams, sometimes have an ordinary
high water mark as well as bed and banks. The agencies and members of
the public thus could struggle to consistently and effectively use
physical indicators to distinguish between a non-relatively permanent
stream flowing for a short duration only in response to precipitation
and a jurisdictional relatively permanent tributary.
Similarly, the agencies solicit comment on whether relatively
permanent should be defined consistent with the pre-2015 regulatory
regime such that relatively permanent waters are those that typically
have standing or flowing water year-round or that have standing or
continuously flowing water at least seasonally (e.g., typically three
months).\52\ This approach explicitly incorporates the ``seasonal''
term used in the Rapanos plurality opinion, although some stakeholders
believe the seasonal approach may not be consistent with Sackett. In
addition, it reflects the approach taken by the agencies since the 2008
Rapanos Guidance, so practitioners would have experience implementing
it. This approach allows for regionalization given the three-month
example provided which could vary to account for seasonal differences
across the country. This approach differs from the proposed rule's
approach because regions which have bodies of surface water that are
standing or continuously flowing with seasonal flow for less than 90
days (e.g., the arid West) would still be considered relatively
permanent, while the rest of the country would simply need to
demonstrate having at least seasonal flow, typically three months in
duration, regardless of their specific wet season length. For example,
under this alternative approach, even if the wet season is five months,
continuous flow could occur for 90 days and be considered relatively
permanent. Whereas under the proposed approach, the entire country
would need to demonstrate flow at least during their regionally-
specific wet season. Alternatively, the agencies could implement
seasonal flow to mean continuous surface flow except during dry
months.\53\ This approach is similar to the proposed approach,
incorporating concepts from the Rapanos plurality and Sackett while
allowing for regional variation, and uses ``dry months'' language from
the Rapanos plurality footnote, but could be read to require more
extended periods of flow than the proposed approach. The agencies also
solicit comment on these alternative approaches, including whether they
are consistent with the Rapanos plurality and Sackett, as well as any
accompanying implementation methods. The agencies welcome comments
generally on the concept of a ``seasonal'' flow duration and what that
term may include, as well as implementation tools that could be used to
identify such flow duration.
---------------------------------------------------------------------------

\52\ Three months was provided as an example of seasonal flow in
the Rapanos Guidance, but under the pre-2015 regulatory regime the
agencies have flexibility to determine what seasonally means in a
specific case. See Rapanos Guidance at 6-7; U.S. Environmental
Protection Agency and U.S. Army Corps of Engineers. ``Memorandum to
Assert Jurisdiction for NWP-2007-945.'' Available at <a href="https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll5/id/1437">https://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll5/id/1437</a> (finding that two months of continuous flow was considered
seasonal flow for site-specific tributaries in a semi-arid region).
\53\ The Rapanos plurality noted that by describing ``relatively
permanent'' waters, the plurality did ``not necessarily exclude
seasonal rivers, which contain continuous flow during some months of
the year but no flow during dry months.'' 547 U.S. at 732 n.5
(emphasis in original).
---------------------------------------------------------------------------

The agencies also solicit comment on the most appropriate method to
identify the wet season under the proposed definition of ``relatively
permanent.'' The agencies propose to focus on precipitation as the one
key driver for wet season identification and intend to use the WebWIMP
outputs reported in APT as a primary tool to help identify the wet
season when precipitation exceeds evapotranspiration rates. Streams
that flow continuously during the wet season are distinct from streams
that flow discontinuously or only in direct response to discrete
precipitation events, such as ephemeral streams. The agencies recognize
that the WebWIMP outputs reported in APT may not have complete
functionality in certain territories, and the agencies are

[[Page 52521]]

exploring ways to improve functionality in those limited circumstances.
Another method could be to identify when the majority of precipitation
occurs in a given location or region based on percentages and utilize
that to identify the wet season, which may better account for
continuous streamflow that can occur in the arid West during monsoon
season. This approach could identify in which months greater than 50%
(or another percentage such as 70%) of the rainfall occurs at the
identified location or region and identify that as the wet season. In
another approach, the agencies could adopt the Wet Season Totals, which
identify the climatologically wettest three months (91 days) of the
year.\54\ The agencies could ensure that this would include multiple
years of data analysis. The agencies solicit comment on whether a
definition of ``wet season'' should be added to the regulatory text to
provide clarity and transparency. The agencies could adopt a definition
that includes the months when precipitation exceeds evapotranspiration
or the agencies could adopt any of the options described above for a
definition.
---------------------------------------------------------------------------

\54\ Funk, C., Harrison, S., Alexander, L., Peterson, P.,
Behrangi, A., and Husak, G. 2019. ``Exploring trends in wet-season
precipitation and drought indices in wet, humid and dry regions.''
Environmental Research Letters 14(11): 115002. Available at <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab4a6c">https://iopscience.iop.org/article/10.1088/1748-9326/ab4a6c</a>.
---------------------------------------------------------------------------

The agencies propose to have the flow ``at least during the wet
season'' be specifically bound by the wet season such that the number
of months with continuous flow would need to be at least throughout the
entirety of the wet season. For example, if a wet season extended for
six months, the stream would need to flow for at least six months
coincident with the identified wet season to be considered relatively
permanent. The agencies solicit comment on whether this is an
appropriate approach for identifying ``at least during the wet
season,'' and whether implementation of this approach is feasible. The
agencies also specifically solicit comment on how this might be
implemented when there may be a lag in the surface hydrology response
to seasonal precipitation as described at section V.C.1 of this
preamble above. Such an approach could result in many streams in the
arid West not meeting the proposed definition of ``relatively
permanent,'' and the agencies solicit comment on the implications of
such an approach in those arid West States. In an alternative approach,
the agencies could interpret ``at least during the wet season'' where
surface hydrology must occur for at least a proportionate amount of
time as the identified wet season duration which would be in response
to the wet season but need not be coincident with the specific wet
season timeframe. For example, if a wet season extended from December
through March (a wet season of four months), the stream would need to
flow for at least four months to be considered relatively permanent,
even if the surface hydrology occurred for four months from February
through May. In another alternative approach, the agencies could
interpret ``at least during the wet season'' where surface hydrology
must occur for at least some months in response to the wet season.
Under this approach, the agencies would not require the flow to occur
throughout the wet season but would still require flow to occur for at
least some months of continuous flow. This duration would extend beyond
merely weeks, or even one month, and would require flow for at least an
extended period of time of some months during or in response to the wet
season. This alternative approach differs from the one described
immediately above in that the flow duration would not be required to be
of equal duration as the duration of the wet season (e.g., a wet season
extending from December through April, a five-month duration, but the
stream has flow duration from March through May, a three-month
duration; such surface hydrology is in response to the wet season but
is not of equal duration). This approach may better account for
climatological differences in certain regions, such as the arid West.
The agencies request comment on whether this alternative approach is
consistent with the plurality opinion in Rapanos and Sackett. To be
clear, the agencies do not intend for the proposed approach or any of
the alternative approaches to encompass ephemeral streams or any
streams that flow only in direct response to discrete precipitation
events.
Another aspect of the proposed definition of ``relatively
permanent'' is to identify when surface hydrology occurs in a given
waterbody at least during the wet season, and a number of
implementation methods and tools could be used. The agencies
acknowledge that landowners often know when surface hydrology is
occurring in waterbodies on their land, and such visual observations
and other local knowledge and records would be helpful when identifying
the occurrence and duration of surface hydrology. One specific tool
that could also be used would be the agencies' regional streamflow
duration assessment methods (SDAMs),\55\ which are rapid field-based
methods that can be used to identify both streams that contain flowing
water continuously during a year of normal rainfall, as well as streams
that contain sustained flowing water for part of the year, typically
during the wet season, where the streambed may be below the water

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