The definition of “waters of the United States” (WOTUS) is once again shifting as the Trump Administration’s EPA and Army Corps of Engineers propose a new rule. The WOTUS designation determines when federal permits are required for work on privately owned land containing water. With each new rewrite the impact to landowners, developers, builders, and anyone working with property has major practical and financial implications.
Background
Under the Clean Water Act (CWA), the EPA and the Army Corps are tasked with regulating WOTUS. If by definition a body of water is determined to be WOTUS, then the landowner must obtain federal permits and/or purchase mitigation credits to alter or fill that land. Conflicting interpretations over what constituted WOTUS created years of uncertainty until the Supreme Court’s 2023 Sackett v. Environmental Protection Agency, decision. It struck down the EPA’s test and narrowed federal authority. The Biden Administration responded soon after with a new WOTUS rule that expanded federal oversight again.
The 2025 Proposed Rule
Released on November 20, 2025, the proposed rule clarifies that WOTUS includes only “relatively permanent” waters—those with standing or continuously flowing surface water year-round or during the wet season. This is consistent with Sackett, which limited jurisdiction to streams, rivers, lakes, and similar features. Wetlands are jurisdictional only if they are adjacent to a WOTUS and share a continuous surface connection, meaning the wetland directly abuts the WOTUS and holds surface water during the wet season. Under the narrowed standard, a wetland qualifies as WOTUS only if it meets all three requirements: 1) it is a true wetland capable of supporting wetland vegetation; 2) it directly touches a WOTUS; and 3) it contains surface water during the wet season. The proposal also excludes all ditches constructed entirely in dry land, while retaining jurisdiction over ditches built in wetlands or tributaries, with rare exceptions for navigable canals or pollutant point sources. Finally, ephemeral waters, areas that flow only after rainfall or snowmelt, are explicitly excluded from WOTUS, eliminating a longstanding source of confusion for landowners and developers. Interestingly, the proposed rule does not clarify the definition of “relatively permanent” waters, a term also left open to interpretation in Sackett.
Bottom Line
The 2025 proposal tightens WOTUS so that fewer wetlands, ditches, and ephemeral features will qualify for federal jurisdiction. Public comment on the proposed rule closes on January 5, 2026. After that, the agencies will evaluate the comments and decide whether to proceed with the rulemaking process or issue a new or modified proposal.