The U.S. Environmental Protection Agency and the U.S. Department of the Army issued a Supplemental Notice of Proposed Rulemaking to seek additional public input on regulatory text for defining “waters of the United States” (WOTUS) under the Clean Water Act. The supplemental options will be evaluated alongside the agencies’ 2025 proposed rule and are intended to implement the Supreme Court’s 2023 Sackett decision. Upon publication in the Federal Register, the supplemental proposal will be open for a 30-day public comment period.
WOTUS defines which waters are covered by federal permitting requirements. In general, discharges of pollutants to protected waters require federal, state, or Tribal permits, and discharges of dredged or fill material typically require a permit from the U.S. Army Corps of Engineers under Section 404 of the Clean Water Act. Clarifying the scope of federal jurisdiction affects compliance obligations and project schedules for utilities, engineers, construction firms, landowners, and other regulated entities.
According to the agencies, the supplemental notice aims to promote transparency, reduce regulatory complexity, and produce a durable final definition that aligns with Sackett while recognizing the roles of states and Tribes in managing water resources. The stated objective is to provide greater predictability for landowners, farmers, ranchers, energy producers, technology firms, developers, and small businesses. Waters determined to be outside federal jurisdiction would continue to be governed by applicable state, Tribal, and local requirements, which vary across jurisdictions.
The agencies noted that public engagement has been a central element of the process, citing a public recommendations docket, listening sessions, and pre-proposal consultations with Tribes, states, and local governments ahead of the 2025 proposal. The 2025 proposed rule received more than 220,000 public comments during a 45-day period that closed on January 5, 2026.
Media reporting described the supplemental options as potentially more sweeping than the November 2025 proposal, which itself would have narrowed federal protections for wetlands nationwide. Some agricultural and rural landowner interests have indicated support for narrower federal jurisdiction, citing property-rights considerations and a desire for clearer permitting boundaries.
The Natural Resources Defense Council (NRDC) strongly criticized the supplemental proposal. The organization said principal options under consideration would generally protect waters that flow every day of the year and wetlands that are permanently flooded, leaving many intermittent and ephemeral streams and seasonally flooded wetlands outside federal coverage. NRDC cited analysis indicating that at least 94% of wetlands and approximately 79% of streams in the continental United States could be at risk of losing federal protection under the scenarios outlined. The group contends the options go beyond what is required by Sackett.
The agencies said the supplemental proposal is intended to broaden the range of options under consideration without excluding those already proposed or predetermining the final rule. As with earlier steps, the public will have 30 days to submit comments after the supplemental notice appears in the Federal Register.