Federal Clean Water Act jurisdiction may be about to get considerably narrower. On September 4, 2026, the U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (Corps) announced a supplemental notice of proposed rulemaking that would limit federal authority over streams and wetlands to those containing water year-round—a “perennial” standard that would go beyond even what the Supreme Court required in Sackett v. EPA, 598 U.S. 651 (2023). The supplemental notice offers two options for revising the definition of “waters of the United States” (WOTUS) under the Clean Water Act (CWA): One would define “relatively permanent” waters as perennial, and the other would require perennial surface water to establish a wetland’s continuous surface connection to a jurisdictional water. If adopted, either option would substantially reduce the number of streams, wetlands and other water features subject to federal permitting, with the sharpest effects in arid and semi-arid regions where rainfall patterns leave many waterways dry for portions of the year.

Reprinted courtesy of Ashleigh K. Myers, Pillsbury and Jillian Marullo, Pillsbury

Ms. Myers may be contacted at ashleigh.myers@pillsburylaw.com
Ms. Marullo may be contacted at jillian.marullo@pillsburylaw.com