Since May 2023, when the U.S. Supreme Court ruled that wetlands must be connected to navigable bodies of water to be protected under the Clean Water Act, the last two administrations have attempted to align the federal definition of “waters of the United States” with the court’s finding.
Most recently, the Trump administration’s Environmental Protection Agency and Army Corps of Engineers announced alternatives to definitions in the draft “Updated definition of ‘Waters of the United States” published Nov. 20, 2025, in the Federal Register.
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The agencies are asking for comments on “revised definitions of ‘relatively permanent’ and ‘continuous surface connection,’ and adding a definition of the term ‘perennial,'” in the supplemental notice of proposed rulemaking published Sept. 9 in the Federal Register. The 30-day public comment period ends Oct. 9. The supplemental proposal and information on how to comment can be found on the Federal Register.
“The EPA’s goal is a durable WOTUS definition that follows the law and ends burdensome regulatory uncertainty,” EPA Administrator Lee Zeldin said in a statement. The supplemental proposed “reflects our continued commitment to transparency and public input, ensuring we have fully considered a wide range of potential policy options.”
Officials clarified that this additional language does not replace anything in the 2025 document but is to be treated as alternative definitions to consider.
Environmental groups argue that these supplemental draft definitions limit the scope of WOTUS, particularly for isolated wetlands, even more than the initial language in the 2025 proposed rule from last November.
“The proposal would limit federal protections for tributary rivers, streams, and lakes to those with standing or continuously flowing water throughout the year, during ordinary conditions. It would also sharply narrow protections for wetlands, requiring them to have continuous, perennial surface water connections to another protected water or, alternatively, be indistinguishably part of a traditional navigable water, the territorial seas, a jurisdictional impoundment, or a jurisdictional tributary,” the Waterkeeper Alliance said last week.
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Waterkeeper Alliance Senior Attorney Kelly Hunter Foster said in the organization’s call to action that if the proposal is finalized, “it would be the most consequential attack on clean water since the Clean Water Act was passed in 1972.”
WOTUS timeline
There are decades of history, amendments, revisions and lawsuits leading up to this latest move to update the definition of WOTUS.
Congress established in 1948 the Federal Water Pollution Control Act, the country’s first major law to address water pollution. That act underwent extensive amendments in 1972, becoming known as the Clean Water Act, and gives the EPA and Army Corps federal jurisdiction over “navigable waters” defined in the act as the “waters of the United States,” or WOTUS.
While the Clean Water Act defines “navigable waters” as “the waters of the United States, including the territorial seas,” there is no further explanation on they types of waterbodies are considered navigable. Rather, the definition of WOTUS can be found in the code of federal regulations as applied to the jurisdictional limits of the authority of the Corps of Engineers and EPA under the Clean Water Act
The agencies established core regulations to define WOTUS in the 1980s, but because of Supreme Court rulings in the 2000s, the scope of protected waters was narrowed. In 2015, the agencies issued a Clean Water Rule to overhaul WOTUS with the intent to clarify regulatory jurisdiction – the first time since the 1980s — but was met with lawsuits around the country, congress.gov states.
The 2015 Clean Water Rule put in place during the Obama administration was rescinded on Oct. 22, 2019, during Trump’s first term, returning WOTUS to the 1980s regulations until the Navigable Waters Protection Rule went into effect June 22, 2020, which also narrowed “the scope of waters that fell under federal jurisdiction,” and was challenged in court, per the EPA.
The Biden administration once in office went through a series of actions to amend WOTUS, landing on the final “Revised Definition of ‘Waters of the United States’” that took effect on March 20, 2023. Then the U.S. Supreme Court in the Sackett v. Environmental Protection Agency lawsuit ruled in favor of the Idaho couple who had been fined for backfilling what the EPA considered protected wetlands on their property. The justices found that “wetlands are covered by the Act only when the wetlands have a ’continuous surface connection’ to waters of the United States—that is, when the wetlands are ‘adjoining’ covered waters.”
The Clean Water Act’s use of the word “waters” only refers to geographical features described in everyday language such “as ‘streams, oceans, rivers, and lakes’ and to adjacent wetlands that are ‘indistinguishable’ from those bodies of water due to a continuous surface connection,” the majority continued.
The ruling did two things: It narrowed the types of wetlands protected by the Clean Water Act, and it made the January 2023 final rule inconsistent. A “final rule to amend” the final “‘Revised Definition of ‘Waters of the United States’” went into effect Sept. 8, 2023, to comply with the Supreme Court ruling.
Shortly after Trump began his second term as president, EPA Administrator Lee Zeldin committed on March 12, 2025, to “deliver on President’s Trump’s promise to review the definition of ‘waters of the United States’” and to revise the 2023 definition. EPA and Army Corps jointly issued a memorandum the same day with guidance on the agencies’ views on the proper implementation of the definition of WOTUS, with “respect to adjacent wetlands,” in consideration of the Sackett case.
The agencies followed through and put out for public comment on Nov. 20, 2025, “a proposed rule that would clarify the definition of “waters of the United States” and fully implement the U.S. Supreme Court’s decision in Sackett v. Environmental Protection Agency.”
Proposed revisions to the 2025 rule
Revisions to WOTUS in the initial 2025 proposed rule “would fully implement” the Sackett decision by “ensuring federal jurisdiction is focused on relatively permanent, standing or continuously flowing bodies of water—such as streams, oceans, rivers, and lakes—and wetlands that are connected and indistinguishable from such waterbodies.”
The agencies asked for public comment during the 45-day window that closed Jan. 5 on adding draft definitions for “continuous surface connection,” “ditch,” “prior converted cropland,” “relatively permanent,” “tributary,” and “waste treatment system”; removing interstate waters; revising exclusions for waste treatment systems, prior converted cropland and ditches; and adding exclusions clarifying that groundwater is not considered WOTUS.
After the draft rule was published, officials said they have received around 220,000 public comments asking for clarification and recommending alternatives to what was initially proposed.
In response, the EPA and Army Corps on Sept. 4 announced the “additional regulatory options” for the 2025 proposed rule to “provide greater regulatory certainty and increase Clean Water Act program predictability and consistency by clarifying the definition” of WOTUS, which was published Sept. 9 in the Federal Register.
The agencies are specifically asking for comments on revised definitions in this latest document for “‘relatively permanent’ and ‘continuous surface connection,’ and adding a definition of the term ‘perennial.'”
The alternative definition for “relatively permanent” is “‘perennial bodies of water.’” And would state that “‘A body of water does not lose its relatively permanent status if it dries up as a result of anomalous events such as drought or dry spell. A body of water also does not lose its relatively permanent status if it dries up for no more than a single period of up to 30 consecutive days in any given year as a result of non-anomalous events resulting in a temporary interruption such as low tide or a regularly occurring dry spell.’”
The agencies proposed in the first update to “define ‘continuous surface connection’ to mean having surface water at least during the wet season and abutting (i.e., touching) a jurisdictional water” and the “’wet season’ for continuous surface connection was intended to be implemented as it was for the proposed definition of ‘relatively permanent.’”
In this supplemental proposal from last week, the agencies are requesting comment on an alternative definition of “continuous surface connection” to mean “’perennial surface water in a wetland that is continuously connected with the surface water in the jurisdictional water such that it is difficult to determine where the jurisdictional water ends and the wetland begins. A temporary interruption in the surface water connection may occur as the result of anomalous events such as drought or a dry spell. A temporary interruption in the surface water connection lasting for no more than a single period of up to 30 consecutive days in any given year may also occur as a result of non-anomalous events such as low tide or a regularly occurring dry spell.’”
The agencies propose defining “perennial” as having “in the regulatory text to mean ‘“’having standing or continuously flowing water every day of the year during ordinary conditions’”’ or, alternatively, to mean ‘“’surface water flowing continuously year-round,’ consistent with the 2020 Navigable Waters Protection Rule.”
Officials said they plan to continue reviewing comments on the 2025 proposed rule along with those received during this new comment period that began Sept. 9. The agencies said they will continue to consider the regulatory options proposed in the 2025 proposed rule in tandem with the supplemental regulatory options and any comments received.
Responses to supplemental proposal
Associated Builders and Contractors Vice President of Government Affairs Kristen Swearingen said that the national construction industry trade association “appreciates the Trump administration’s continued work to establish a clear, durable and reasonable definition of WOTUS that brings clarity to ABC contractor members and maintains important water quality protections.”
The Southern Environmental Law Senior Attorney Mark Sabath said that this latest version is “yet another affront to communities that rely on clean water and healthy wetlands. The words have changed, but the result would be the same if this rule is finalized: more severe flooding and greater threats to water quality.”
American Farm Bureau Federation President Zippy Duvall commented that “the new proposed rule “provides a clear understanding of federal jurisdiction, which is critical for farmers who may face severe penalties or even jail time for unknowingly violating the law.”
The National Wildlife Federation argues that the revised proposal “greatly” limits the streams and wetlands that can be protected by the Clean Water Act. “One thing is clear: If we don’t protect our streams and wetlands the cost of dirtier drinking water and increased flooding will flow downstream to households at a time when most Americans are living paycheck to paycheck,” Jim Murphy, the associate vice president for legal advocacy, said.
Natural Resources Defense Council’s Director of Freshwater Ecosystems Jon Devine said that this proposal “denies federal protection to virtually all wetlands and more than three quarters of our streams, endangering drinking water supplies and flood-prone communities – and the agencies admit it themselves. The proposal would virtually eliminate protection for freshwater wetlands.”
