The US Environmental Protection Agency and the US Army Corps of Engineers are proposing new guidelines to clarify when wetlands are protected under the Clean Water Act based on the 2023 milestone. Sackett v. EPA Decision of the Supreme Court.
Confusion over which bodies of water are federally protected from construction impacts under the law as “waters of the United States” has persisted for more than four decades, with definitions challenged in at least three Supreme Court cases, including the most recent one. Sackett 2023 decision. In that ruling, the court’s definition more closely aligned with one outlined by Associate Justice Antonin Scalia in 2006. rapanos opinion: Discarding the “significant nexus” test developed by Justice Anthony Kennedy in the same case.
The agencies published a proposed rule in November 2025 to comply with the Supreme Court’s ruling, which said that to be federally protected as “waters of the United States,” wetlands or other bodies of water must have a continuous connection to navigable surface waters, at least during wet seasons. But the EPA proposal created additional confusion about what constitutes the “wet season” and where and when those seasons occur, says Larry Liebesman, a former Justice Department attorney who is now a senior adviser at environmental permitting consultancy Dawson & Associates.
To provide needed clarity, EPA and the Corps released a supplemental proposal on Sept. 4 that they say will help the two agencies evaluate more options as they work toward a final rule that fully implements the 2023 Sackett ruling.
“I think what they’ve tried to achieve is a more simplified approach that makes it easier for landowners to identify which are relatively permanent waters, which wetlands are contiguous and connected to those waters, and therefore federally regulated, and which are not,” Liebesman told ENR.
Trade groups generally support the most recent actions of agencies.
Prianka Sharma, vice president and regulatory affairs counsel for the American Association of Highway and Transportation Builders, said in an email that based on an initial review, the latest proposal will provide “greater clarity on which transportation construction water features, including certain ditches and drainage features, are subject to federal jurisdiction.”
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The supplemental proposal appears to “draw a clearer line around many seasonal and intermittent features while maintaining federal protections for jurisdictional waters. This is a potentially significant improvement for transportation construction projects that have long faced uncertainty about when federal permitting requirements apply,” he said.
Kristen Swearingen, vice president of government affairs for Associated Builders and Contractors, added that she supports “EPA’s efforts to provide greater regulatory certainty, reduce unnecessary permitting delays, and ensure that federal authority is consistent” with the Sackett sentence
But environmental groups say the latest action will only further erode protections for waters that have traditionally fallen under the jurisdiction of the Clean Water Act, protecting “perennial” waters that flow virtually every day of the year under normal conditions, but allowing a single outage of no more than 30 consecutive days annually. Wetlands would only be protected where perennial surface water continuously connects them to a protected body of water Only the portion of the wetland that is “indistinguishable” from the water would remain protected, according to the Natural Resources Defense Council. .
Jon Devine, director of the freshwater ecosystem group, said in a statement that according to the agencies’ own analyses, most streams would lose protections, with the western United States the hardest hit. “This proposal declares open season on the nation’s waterways,” denying federal protections to virtually all wetlands and more than three-quarters of streams, he said.
The public will have 30 days to comment on the new proposal after its publication in the Federal Register.
Liebesman speculates that the EPA may issue a final rule before the end of the year.
