EPA and Army Propose Update to the Definition of WOTUS
On November 17, 2025, the U.S. Environmental Protection Agency (“EPA”) and the U.S. Department of the Army (“the agencies”) released a proposed rule that updates the definition of “Waters of the United States” (“WOTUS”) under the Clean Water Act (“CWA”). The proposal aims to bring the regulations into compliance with the U.S. Supreme Court’s decision in Sackett v. EPA, 598 U.S. 651, 143 S. Ct. 1322 (2023).
This article summarizes the proposed changes and why they matter for landowners, developers, and regulated entities. For additional background, readers may want to explore earlier WOTUS analysis on this website, including discussions of the Sackett decision and the history of the “significant nexus” test.
Why the Agencies Are Updating the Definition of WOTUS
Before Sackett, agencies used the “significant nexus” test to determine federal jurisdiction. Under that test, waters could fall under the CWA if—alone or combined with similar waters—they significantly affected the integrity of traditionally navigable waters. This standard came from Rapanos v. United States, 547 U.S. 715, 719, 126 S. Ct. 2208, 2214 (2006) (Kennedy, J., concurring).
The Supreme Court rejected the significant nexus test in Sackett. The Court held that the CWA covers only those wetlands with a continuous surface connection to waters that are themselves WOTUS. The connection must make the wetlands “indistinguishable” from those waters. Sackett, 598 U.S. at 684.
To follow Sackett, the agencies now propose several key regulatory revisions.
Key Proposed Changes
1. New Definition of “Relatively Permanent”
The prior regulations used the phrase “relatively permanent” but did not define it. The proposed rule defines it as:
- Standing or continuously flowing bodies of surface water
- That exist year-round or at least during the wet season
This means seasonal waters can still qualify as WOTUS if they persist during the wet season.
2. Clarified Definition of “Continuous Surface Connection”
The agencies propose that a continuous surface connection exists when waters:
- Have surface water at least during the wet season, and
- Abut (touch) a jurisdictional water
The proposal emphasizes that the water body must directly touch the jurisdictional water. Any land feature between them breaks the surface connection.
3. Other Important Term Updates
The proposed rule also revises several additional terms:
Removal of “Intrastate”
- The term “intrastate” would be removed.
- This makes clear that a water body is not WOTUS solely because it crosses state lines if it does not otherwise meet the criteria.
Revised Exclusion for “Ditches”
- Only ditches constructed or excavated entirely on dry land qualify for exclusion from WOTUS.
Updated Exclusion for “Prior Converted Cropland”
- The agencies clarify when abandonment of prior converted cropland may allow reclassification as a wetland.
Expanded Definition of “Waste Treatment Systems”
- The proposal further explains which waste treatment systems fall outside the definition of WOTUS.
Purpose of the Proposed Changes
These revisions aim to help States, Tribes, and private parties understand which water bodies fall under the CWA after Sackett. Clearer definitions allow landowners and regulators to make informed land?use and water?use decisions with greater confidence.
What Happens Next?
The proposed rule has been submitted for publication in the Federal Register. A 45-day public comment period will begin once publication occurs. A final rule will be released after the agencies review and consider submitted comments.
Litigation over WOTUS is expected to continue, and this rulemaking will likely be part of that ongoing legal landscape.
For further context, readers can review other WOTUS?related analyses on water-law.com, which discuss both the long regulatory history leading to Sackett and the challenges that continue to shape federal jurisdiction over water resources.
