EPA proposes to define the words Sackett left undefined

The Environmental Protection Agency and the Department of the Army published a proposed rule on 20 November 2025 revising the definition of “waters of the United States,” the term that fixes the reach of the Clean Water Act.¹ The agencies state they are acting “in light of the U.S. Supreme Court’s 2023 decision in Sackett v. Environmental Protection Agency,” and the proposal’s central work is to put into regulation two phrases the Court used but never defined (see Sackett narrows the Clean Water Act to adjoining wetlands).¹² Comments are due 5 January 2026, under docket EPA-HQ-OW-2025-0322 and RIN 2040-AG44.¹

1. The proposed definition resolves the question the Court split on, and resolves it against the four. Sackett held that the Act reaches wetlands with a “continuous surface connection” to a covered water; Justices Kavanaugh, Sotomayor, Kagan and Jackson said that test wrongly collapsed the statute’s word “adjacent” into “adjoining,” and that a marsh separated from a river by a levee is still adjacent to it.² The agencies propose: “Continuous surface connection means having surface water at least during the wet season and abutting (i.e., touching) a jurisdictional water.”¹ The parenthetical is the whole dispute. They also propose that “[r]elatively permanent means standing or continuously flowing bodies of surface water that are standing or continuously flowing year-round or at least during the wet season,” and note that both terms are being added “for the first time to the agencies’ regulations.”¹

2. The consultation record ran the other way from the proposal. The agencies report that on whether features such as culverts and berms sever a continuous surface connection, “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,” while “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.”¹ The proposed definition of “tributary” excludes a water body that connects downstream only through “a channelized non-jurisdictional surface water feature, subterranean river, culvert, dam, tunnel, or similar feature.”¹

3. One proposed change does not come from Sackett at all. The rule “would remove the category of interstate waters from the definition of ‘waters of the United States’” — a category concerning waters crossing state lines, which the 2023 wetlands decision did not address.¹ The agencies rest it on navigability and on SWANCC, and argue the change “would likely have few practical impacts,” citing their own count: of the approved jurisdictional determinations the Corps finalised “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.”¹³

4. The agencies say the rule narrows coverage but do not say by how much. They state that “compared to the baseline, the proposed rule would define fewer waters and wetlands as within the scope of the Clean Water Act,” and that section 404 “would likely be the Clean Water Act program most impacted by the proposed rule, with projected reductions in the number of permits and required mitigation.”¹ The supporting economics are qualitative: this is “a significant regulatory action that was submitted to the Office of Management and Budget,” yet the agencies record that they “are also evaluating options for development of a quantitative analysis of the effects of the proposed rule and solicit input on data and methods that could assist in that development.”¹ The comment window runs 46 days across Thanksgiving and Christmas, against the 60 days Executive Order 12866 says agencies “should” allow in most cases.¹⁴