WOTUS Update: New Supplemental Proposed Rule

The U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers have released a pre-publication Supplemental Notice of Proposed Rulemaking (SNPRM) addressing the definition of “Waters of the United States” (WOTUS) under the Clean Water Act.

The supplemental proposal builds on the agencies’ November 2025 proposed rule implementing the Supreme Court’s 2023 Sackett v. EPA decision and responds to approximately 220,000 comments submitted on that proposal.

Importantly for ICSC members, the new proposal seeks comment on alternatives that could further narrow the scope of waters and wetlands subject to federal Clean Water Act jurisdiction.

The supplemental proposal focuses on two key concepts:

• “Relatively permanent” waters: The agencies are considering a new bright-line approach under which a water generally would qualify as relatively permanent only if it is perennial, meaning it has standing or continuously flowing water every day of the year under ordinary conditions. The proposal would allow limited exceptions for droughts and certain temporary interruptions, including a regularly occurring dry spell of up to 30 consecutive days. Waters that do not satisfy this standard, including most intermittent and ephemeral features, generally would fall outside federal jurisdiction under this approach.
• “Continuous surface connection” for wetlands: The agencies are also considering a more restrictive test for determining when wetlands are jurisdictional. Under the supplemental option, a wetland generally would need to have perennial surface water continuously connected to a jurisdictional water such that it is difficult to determine where the water ends and the wetland begins, subject to limited temporary interruptions such as drought, low tide or certain dry spells. This would replace the November proposal’s approach, which generally looked for surface water during the wet season and physical abutment with a jurisdictional water.

A narrower and clearer definition of WOTUS could reduce uncertainty surrounding whether wetlands, streams and other water features on commercial properties require federal Clean Water Act permitting. EPA and the Army themselves acknowledge that the supplemental approaches could result in a significant reduction in federally jurisdictional streams and wetlands, particularly in the arid West. For developers and property owners, that could affect site planning, environmental due diligence, Section 404 permitting, mitigation requirements and the time and cost associated with development and redevelopment projects.

The supplemental proposal does not reopen every element of the November 2025 proposal. Among other things, the agencies are not proposing new alternatives concerning the previously proposed exclusions for certain ditches, prior converted cropland, waste treatment systems and groundwater.

It also does not establish a new requirement that Corps districts accept or process stand-alone Approved Jurisdictional Determination (AJD) requests, nor does it direct regional/district offices to issue an AJD when no Section 404 permit application is pending. The proposal does discuss AJDs, but mainly as part of implementing the substantive definition of WOTUS.

The SNPRM was signed by the Army on September 2 and EPA on September 3 and is awaiting publication in the Federal Register. Once published, stakeholders will have 30 days to submit comments.

ICSC is reviewing the proposal and will evaluate opportunities to provide input on behalf of the commercial real estate industry through our partners at the Waters Advocacy Coalition.

For more information contact Abby Jagoda at ajagoda@icsc.com.