By STAFF REPORTS
The Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers have published a new proposed definition of “waters of the United States” (WOTUS) in the Federal Register. The notice, titled Definition of “Waters of the United States,” 90 FR 52,498 (Nov. 20, 2025), represents the agencies’ most detailed effort to date to align federal Clean Water Act jurisdiction with the Supreme Court’s 2023 Sackett v. EPA decision.
The proposal revises major components of the federal jurisdictional framework—including “relatively permanent” waters, adjacency, continuous surface connection, and several key exclusions—while laying out multiple alternative regulatory approaches for public consideration. The rulemaking reflects months of listening sessions, federalism consultation, and tribal engagement conducted earlier in 2025.
Key Highlights of the Proposed Rule
- Revised “Relatively Permanent Waters” Standard
The proposal would shift to a wet-season–based approach for determining whether tributaries and certain waterbodies qualify as “relatively permanent.” It also describes how field staff should identify flow duration and hydrologic persistence. - Updated “Continuous Surface Connection” Test
The agencies propose amendments clarifying when wetlands are considered adjacent, emphasizing physical abutment and seasonal surface water presence. The new approach also addresses wetland mosaics and permafrost wetlands. - New Definition of “Tributary”
The proposal adopts a narrower, flow-based definition of “tributary,” which must:- Convey relatively permanent flow (standing or continuously flowing water during the wet season), and
- maintain a connection to a downstream traditional navigable water.
A tributary may still pass through natural or artificial (e.g. culverts, pipes, or ditches) features, even if those features are not jurisdictional on their own, as long as they convey relatively permanent flow. Importantly, a non-relatively permanent segment downstream will sever federal jurisdiction for all upstream segments.
- Revised Treatment of Lakes and Ponds
The rule proposes removing “intrastate” as a jurisdictional qualifier and clarifying how lakes and ponds relate to the continuous surface connection standard. - Changes to Longstanding Exclusions
The proposal updates definitions and administration of the waste treatment system exclusion, the prior converted cropland exclusion, and the ditch exclusion—each with multiple options on the table for public input.
Sections Where Comments on Alternative Approaches are Specifically Requested
The publication highlights several areas where the agencies are actively inviting comment on alternative regulatory paths:
- Relatively Permanent Waters
Includes alternative methods for determining seasonal flow duration and identifying wet seasons (e.g., fixed timeframes such as 90 days vs. regionally specific hydrologic periods). - Continuous Surface Connection
Presents options ranging from a strict physical abutment standard to a more stringent requirement that wetlands, lakes, or ponds must have permanent (year-round) surface water to qualify as adjacent. - Waste Treatment System Exclusion
Provides alternative definitions and implementation frameworks for the exclusion. - Prior Converted Cropland
Includes an alternate approach under which USDA would serve as the sole authority for determinations. - Ditch Exclusion
Seeks input on different ways to define “ditch,” distinguish upland-excavated features, and determine when ditches with intermittent or ephemeral flow should be excluded.
Public Comment Period Open Until January 5, 2026
The rule is open for public comment for 45 days, with a deadline of January 5, 2026. Written comments must reference Docket ID No. EPA-HQ-OW-2025-0322 and may be submitted through the website at Regulations.gov or orally during one of two hybrid public meetings (dates to be announced). EPA and the Army Corps will consider all written and oral feedback before publishing a final rule in 2026.
