New WOTUS Proposal Could Ease CWA Permitting for Development Projects: Comments Due Oct. 9

The U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (USACE) published a supplemental notice of proposed rulemaking on Sept. 9 that would significantly narrow their definition of the waters of the United States (WOTUS) under the Clean Water Act (CWA). The notice amends the agencies’ Nov. 20, 2025, proposed rule, which limited which waters the CWA regulated in line with the Supreme Court’s ruling in Sackett v. EPA.

If finalized, the proposal would shrink the scope of waters and wetlands subject to CWA permitting, potentially reducing permitting obligations and costs for development and infrastructure projects. Landowners and developers should consider the rule’s impacts and submit comments before the Oct. 9 deadline.

Recent Changes to the WOTUS Definition

Whether water features are or are not considered WOTUS under the CWA determines whether discharges of pollutants or dredge and fill material to those waters are prohibited without a permit. The WOTUS definition has been the subject of regulatory uncertainty in recent years. The current rulemaking responds to the Supreme Court’s landmark decision in Sackett, which narrowed federal CWA jurisdiction by limiting which waters it regulated.

In Sackett, the Court rejected the “significant nexus” test that guided agency jurisdictional determinations since Rapanos v. United States, holding that the CWA extends only to “relatively permanent” waters connected to traditional navigable waters and wetlands with a “continuous surface connection” to such waters.

In September 2023, the EPA and USACE, under the Biden Administration, issued a revised definition of WOTUS to reconcile the agencies’ definition with the Supreme Court’s decision in Sackett. In response to concerns that this definition did not fully conform to the Supreme Court’s decision, the agencies, then under the Trump administration, proposed the updated definition of WOTUS in November 2025.

The updated definition took a narrower view as to what waters were covered under the CWA.  Under that initial proposal, the agencies proposed defining “relatively permanent” waters 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.”  The agencies defined “continuous surface connection” to mean “having surface water at least during the wet season and abutting (i.e., touching) a jurisdictional water.” 

The agencies received public comments on that proposal. The supplemental notice now refines the agencies’ definition of those two terms to reflect the results of this public participation process. If finalized, the proposed change will further reduce CWA jurisdiction.

“Relatively Permanent” Waters

The supplemental notice eliminates waters that flow “during the wet season” from the definition of “relatively permanent” waters, and instead defines “relatively permanent” to mean “perennial” bodies of water. Perennial bodies are defined as standing or continuously flowing water present every day of the year under ordinary hydrological conditions. This definition removes most intermittent streams from CWA jurisdiction.

The proposed rule includes two narrow exceptions:

1. 1. For anomalous events, such as a drought, a water body would retain jurisdiction for up to five years.
   2. For non-anomalous events, such as low tide or regularly occurring dry spells, a single dry period of up to 30 consecutive days in any given year would not eliminate jurisdiction.

The agencies anticipate the greatest impact in western regions, particularly the arid West, where intermittent streams are prevalent.

“Continuous Surface Connection” for Wetlands

For wetlands, the supplemental notice revises the definition of “Continuous Surface Connection” to eliminate from the CWA’s jurisdiction wetlands that have surface water “at least during the wet season.” It instead requires that a wetland have “perennial surface water.”

The supplemental notice also replaces the requirement that the water in a wetland be “abutting (i.e., touching) a jurisdictional water,” such as a lake or river, with a requirement that the surface water 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.”

The agencies also clarified that under this revised definition, only the portion of a wetland indistinguishably part of the jurisdictional water would be subject to CWA jurisdiction. The anomalous and non-anomalous exceptions described above would apply. Because most wetlands do not contain perennial surface water, the agencies anticipate that most currently jurisdictional adjacent wetlands would not satisfy the definition.

Potential Impact on Permitting and Development

EPA and USACE characterize the proposal as deregulatory and expect it to reduce the number of federally regulated waters and wetlands. The most significant impact will affect permits issued under Section 404 of the CWA, which authorizes the deposit of dredge and fill material in a WOTUS, usually done as part of a larger construction project.

If finalized, landowners, developers, infrastructure and energy projects, and agricultural operations would have to seek fewer Section 404 permits, reducing federal compliance costs. The impact would be greatest in areas where intermittent streams and non-perennial wetlands constitute a substantial portion of currently regulated features.

Landowners and developers should continue to evaluate potentially regulated waters on a property-specific basis. Even if a final WOTUS rule is ultimately promulgated, determining whether a particular aquatic feature is jurisdictional will remain a fact-specific inquiry.

The absence of federal CWA jurisdiction does not mean a water or wetland is unregulated. Many states maintain their own “waters of the state” designations that may extend to features no longer covered under the federal WOTUS definition. Project proponents should evaluate applicable state and local regulatory requirements before concluding that a feature is outside permitting jurisdiction. States, tribes and local governments may independently regulate wetlands, streams, water quality impacts, floodplains and development activities.

Comments on the supplemental notice must be received on or before Oct. 9, 2026. Interested parties should assess how the proposed definitions could affect existing operations, planned development and pending permit applications.

Please contact Britt Brandon, David Topping, Phillip Dupré, Sophie Gray or any member of Phelps’ Environmental team with questions.