Executive Summary
The U.S. Environmental Protection Agency and the Department of the Army have taken another step in their effort to redefine waters of the United States based on comments received on the November 2025 Proposed Rule. On September 9, 2026, they published a Supplemental Notice of Proposed Rulemaking that considers limiting “relatively permanent” waters to perennial water bodies and requiring perennial surface water to connect a wetland with another covered water. Most intermittent streams and wetlands currently treated as jurisdictional would fail these proposed tests, according to the agencies’ analysis. The proposal does not establish a final rule, but it introduces one of the most restrictive interpretations under consideration as agencies implement the Supreme Court’s decision in Sackett v. EPA.
What Happened
The WOTUS definition determines which waters fall under several federal Clean Water Act programs, including Section 404 permitting. Before a permit application is submitted, regulators must first determine whether a stream, wetland or other aquatic feature falls within federal jurisdiction. Following the Supreme Court’s 2023 Sackett decision, which narrowed the scope of federally regulated waters, the EPA and Army began revisiting the entire definition.
Their November 2025 proposal, published at 90 Federal Register 52498, attempted to implement the…