The Last Wave: EPA And Army Corps Seek To Conform WOTUS Definition To Sackett

Highlights

• The U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers on Nov. 17, 2025, provided a pre-publication version of their proposed rule intended to provide greater regulatory certainty by clarifying the definition of "waters of the United States" (WOTUS).
• The proposed rule aims to align with the U.S. Supreme Court's decision in Sackett EPA, which narrowed the scope of federal jurisdiction.
• This Holland & Knight alert provides a summary of how the rule would define WOTUS moving forward.

The U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers on Nov. 17, 2025, announced the release of a proposed rule revising the definition of "waters of the United States" (Proposed WOTUS Rule). The rule is intended to resolve the regulatory uncertainty that has persisted for decades regarding the scope of federal jurisdiction. (See Holland & Knight's previous alerts, "Waters of the U.S. Rule Will Significantly Expand Federal Authority," Jan. 19, 2023, "Sackett Decision Provides Clarity, Substantially Restricts Clean Water Act Jurisdiction Scope," May 26, 2023, and "Waters of the United States Rule Revised in Response to Sackett Decision," Sept. 7, 2023.)

Among other things, the Proposed WOTUS Rule:

• establishes that jurisdictional tributaries must connect to traditional navigable waters either directly or through other features (e.g., a culvert) that provide predictable and consistent flow
• defines critical terms consistent with the Sackett decision, including definitions of "relatively permanent" and "continuous surface connection" with respect to adjacent wetlands
• clarifies that ephemeral waters (i.e., those with surface water flowing or standing only in direct response to precipitation) are not jurisdictional because they are not relatively permanent
• removes automatic jurisdiction for "interstate waters"
• adds and expands certain exclusions for prior converted cropland, ditches, wastewater treatment systems and groundwater

The Proposed WOTUS Rule aligns with the goals of the 2025 WOTUS Guidance and rulemaking announcement, aiming to provide consistency that is squarely in line with the U.S. Supreme Court's reasoning in Sackett v. EPA and borrows some exclusion concepts from the 2020 Navigable Waters Protection Rule (NWPR) promulgated during the first Trump Administration. Below summarizes the proposed amendments to the WOTUS definitions in 33 C.F.R. § 328.3 and 40 C.F.R. § 120.2.

New Proposed Definitions

The Proposed WOTUS Rule adds definitions for certain terms that are intended to guide application of the Sackett standard, including:

1. "Relatively permanent" is proposed to be defined as "standing or continuously flowing bodies of surface water that are standing or continuously flowing year-round or at least during the wet season." The Proposed WOTUS Rule makes clear that ephemeral waters (i.e., those with surface water flowing or standing only in direct response to precipitation) are not jurisdictional because they are not relatively permanent. The agencies stated that the phrase "at least during the wet season" requires extended periods of predictable, continuous surface hydrology occurring in the same geographic feature year after year in response to the wet season, such as when average monthly precipitation exceeds average monthly evapotranspiration. The agencies are seeking comment on the most appropriate method to identify the wet season under the proposed definition of "relatively permanent." The proposed rule stresses the notion that such information should be readily available to ordinary citizens and trained professionals, such as through personal observations of field conditions. They indicate that they intend to use the metrics from the web-based Water-Budget Interactive Modeling Program (WebWIMP) as a primary source for identifying the wet season as opposed to brightline flow volumes or duration. There is an open question as to whether the flow would have to be during the entirety of the wet season or based on some proportion of that season, and they seek comment on that issue.
2. "Tributary" is proposed to be defined as "a body of water with relatively permanent flow, and a bed and bank, that connects to a downstream traditional navigable water or the territorial seas, either directly or through one or more waters or features that convey relatively permanent flow." The Proposed WOTUS Rule clarifies that features without relatively permanent flow would sever jurisdiction. This definition is fairly consistent with existing practice, essentially treating natural, man-altered and manmade waterbodies as tributaries as long as the waters meet the "relatively permanent" standard set forth in Sackett. Tributaries under the proposed rule may also connect through certain features, both natural (e.g., debris piles, boulder fields or beaver dams) and artificial (e.g., culverts, ditches, pipes, tunnels, pumps, tide gates or dams), even if such features themselves are non-jurisdictional under the proposed rule, as long as those features convey relatively permanent flow. The proposed rule solicits comment on all aspects of the proposed definition of "tributary" and implementation of the definition, including whether to require "bed and banks or additional physical characteristics" in the definition. The agencies also request comment whether manmade features can connect tributaries downstream when they convey relatively permanent flow or if they should sever downstream jurisdiction in all cases other than as part of a water transfer. Under past attempts to address this issue a tributary does not lose its jurisdictional status if it contributes surface water flow to a downstream jurisdictional water through a channelized non-jurisdictional surface water feature such as a culvert, dam, tunnel or other similar artificial feature.
3. "Continuous surface connection," which is a prerequisite for adjacent wetlands to be considered WOTUS, is proposed to be defined as "having surface water at least during the wet season and abutting (i.e., touching) a jurisdictional water," thereby creating a two-part test requiring both abutment of jurisdictional water and having surface water at least in the wet season. As described by the agencies, this proposed definition is intended to include wetlands that have "at least semipermanent surface hydrology," which they believe satisfies the indistinguishability aspect of the Sackett decision, and excludes wetlands with only saturated soil fed by groundwater. Additionally, only the portion of the wetland that meets these two factors would be considered jurisdictional adjacent wetlands, regardless of the full scope of the wetland itself. The agencies also propose that culverts do not inherently sever the continuous surface connection when the culvert serves to extend the relatively permanent water. This would be demonstrated by relatively permanent water flow being present through the culvert, as well as an ordinary high watermark within the culvert, which provides the lateral limits of a tributary extending through the culvert. They are seeking comments on this approach, which would be likely very common such as when a stream passes under a roadway. The agencies seek comment on an alternative approach whereby wetlands, lakes and ponds would have a "continuous surface connection" only if they abut (i.e., touch) a jurisdictional water and have a perennial presence of surface water (i.e., it is year-round). Only wetlands that have permanent surface water, in addition to abutting a jurisdictional water, would be WOTUS under this alternative approach.

Proposed Changes to Exclusions

The Proposed WOTUS Rule proposes a new groundwater exclusion and revisions to certain existing exclusions, and adds corresponding definitions as follows:

1. Groundwater. The Proposed WOTUS Rule would add a new exclusion for groundwater, previously proposed in the 2020 NWPR, codifying the existing practice and historic understanding that groundwater is not WOTUS. The exclusion would expressly include groundwater drained through subsurface drainage systems.
2. Prior Converted Cropland. Under the existing 2023 WOTUS Rule, this existing exclusion expires upon a change in use of the land. The Proposed WOTUS Rule would clarify that the prior converted cropland exclusion would no longer apply when the cropland is abandoned for agricultural purposes for at least five years and the land has reverted to wetlands. The Proposed WOTUS Rule clarifies that the wetland is not automatically jurisdictional at that time; it would be jurisdictional only if it meets the requirements for an adjacent wetland. The Proposed WOTUS Rule also explains that "agricultural purposes" is broadly considered to include a variety of agricultural uses, including idling land for conservation uses and soil recovery.
3. Ditches. In an attempt to address confusion with respect to this existing exclusion, the Proposed WOTUS Rule proposes simply that all ditches, including roadside ditches, that are constructed or excavated entirely in dry land are not WOTUS, even if those ditches have relatively permanent flow and connect to jurisdictional waters. The only "ditches" that are intended to fall outside of this exclusion are tidal or navigable-in-fact ditches (i.e., canals).
4. Wastewater Treatment Systems. The agencies proposed to broaden this exclusion to include all components of a waste treatment system, which the agencies believe largely clarifies existing practice.

Proposed Removal of Interstate Waters and Intrastate Lakes and Ponds

The Proposed WOTUS Rule removes "interstate waters" from the WOTUS definition due to its overbreadth following Sackett. As explained by the agencies, "interstate waters" can be relatively permanent but do not have to be. Removal of "interstate waters" from the WOTUS definition removes an automatic jurisdictional determination with respect to such waters and instead requires them to be evaluated under the other jurisdictional categories and two-part test set forth in Sackett. The 2023 post-Sackett revisions to the 2023 WOTUS Rule already removed "interstate wetlands" from the WOTUS definition, meaning this proposed removal should not substantially affect the jurisdictional status of existing interstate wetlands.

For similar reasons, the agencies proposed to remove "intrastate" from the lakes and ponds category of the WOTUS definition to make clear that the "relatively permanent" standard applies regardless of whether the water is interstate or intrastate.

Impacts to Wetlands

Overall, with respect to wetlands, the Proposed WOTUS Rule reaffirms the existing law of the land set forth in Sackett that wetlands must be indistinguishable from jurisdictional waters through a continuous surface connection. The Regulatory Impact Analysis prepared by the agencies for the Proposed WOTUS Rule estimates that approximately 19 percent of wetlands listed on the National Wetlands Inventory would be considered WOTUS under the Proposed WOTUS Rule. In particular, the limitation of jurisdictional wetlands to those portions that have surface water at least during the wet season and abut a jurisdictional water are intended to further limit the scope of permafrost wetlands that are considered to have a continuous surface connection and aid the agencies in making jurisdictional determinations with respect to wetland mosaics.

The Proposed WOTUS Rule also provides implementation guidance for each of the above changes to clarify how these proposed changes would work in practice for field personnel.

Conclusion

This proposed rulemaking aims to solidify Sackett and provide clarity and durability to a longstanding debate. Only time will tell if the Proposed WOTUS Rule affords the finality that would benefit regulators and industry members alike.

The agencies are soliciting comments on the Proposed WOTUS Rule. Regulated entities may submit public comments, identified by Docket ID No. EPA-HQ-OW-2025-0322, within 45 days of publication in the Federal Register.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.