The Environmental Protection Agency and the U.S. Army Corps of Engineers published a supplemental proposed rule seeking additional public comment on the definition of “waters of the United States” on Sept. 4.
One of the most consequential and contested regulations in American environmental law, the supplemental notice accompanies a 2025 proposed rule and asks stakeholders to weigh in on additional regulatory language, according to the EPA.
The WOTUS definition determines which water bodies fall under federal Clean Water Act jurisdiction, directly affecting permitting requirements for farmers, developers, municipalities, energy companies and industrial operations nationwide.
The regulatory process follows years of litigation over prior WOTUS definitions under multiple administrations, including the Supreme Court’s landmark 2023 ruling in Sackett v. EPA, which significantly narrowed the scope of federal jurisdiction over wetlands.
For American farmers, the WOTUS definition determines whether a drainage ditch or seasonal stream on their property triggers federal permitting requirements. For developers, it affects the cost and timeline of construction projects near any water feature. For communities, it shapes the level of federal protection for the waterways that supply drinking water.
The supplemental notice is expected to draw significant comment from agricultural organizations, environmental groups, homebuilders, energy companies and local governments, all of which have major stakes in the final rule.
The final WOTUS definition will determine federal permitting authority over tens of millions of acres of wetlands and streams, making it one of the most far-reaching regulatory actions in the EPA’s portfolio.