Proposed Update to Definition of WOTUS: Will Federally Regulated Wetlands Continue to Shrink?

Change in Adjacent Wetlands

• Adjacent wetlands must be indistinguishable from jurisdictional waters through a continuous surface connection, which means that they must abut a jurisdictional WOTUS and contain surface water throughout the entire wet season (except in times of extreme drought).
• Wetlands (or parts of a wetland) without semipermanent surface hydrology, including wetlands with only saturated soil conditions supported by groundwater, would no longer be considered adjacent wetlands.
• Mosaic wetlands under the proposed rule, would not be considered ‘‘one wetland,’’ and would be delineated individually.

Relatively Permanent Water (RPW) Under the Proposed Rule

• Currently, informal practice by some USACE districts is to use previous Rapanos guidance stating a water feature with surface water at least three months out of the year (or less in some cases) has relatively permanent flow.
• Under the Proposed Rule, an RPW would have to contain surface water for the entire wet season.
• However, even the Proposed Rule itself states: “It may be more challenging to identify whether a stream flows year-round or a few days less than year-round. Such methods or the use of remote tools may require repeated or continuous monitoring over the course of a year or longer to ensure water is standing or flowing year-round.” Such monitoring is unlikely to be time-efficient or cost-effective. Even with repeated monitoring, observing let alone delineating thin layers of surface water amid dense vegetation can be daunting whether in the field or viewing remote imagery.

Definition of Tributary Under the New Rule

• Tributaries would be defined as water features that are RPWs, flow downstream to a traditional navigable water (TNW) such as the ocean or certain large lakes and rivers, and would now also have to have a bed and banks. This is unlikely to have a substantial effect on WOTUS determinations as most streams, rivers, ditches and channels exhibit bed and banks.

The agencies propose defining the term “ditch” to mean “a constructed or excavated channel used to convey water.” Under the Proposed Rule, the updated ditch exclusion would be revised such that RPW ditches would also be excluded. However, consistent with current practice, ditches that are constructed in tributaries or that relocate a tributary would not be excluded.

In the case of a tributary that contributes flow to the ocean or a downstream water^[1] through an excluded ditch, as long as the ditch has relatively permanent flow, it does not sever jurisdiction upstream under the Proposed Rule. Similar logic applies to wetlands interrupting a tributary.

[1] Paragraph (a)(1) Waters of the United States [currently] means: Waters which are: (i) Currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide; (ii) The territorial seas; or (iii) Interstate waters, including interstate wetlands;

According to the new, Proposed Rule: “Tributaries under the proposed rule may also connect through certain [non-jurisdictional] features, both natural (e.g., debris piles, boulder fields, beaver dams) and artificial (e.g., culverts, ditches, pipes, tunnels, pumps, tide gates, dams), even if such features themselves are non-jurisdictional under the proposed rule, so long as those features convey relatively permanent flow.”

Culverts would not sever jurisdiction when the culvert serves to extend an RPW such that the water directly abuts a wetland, consistent with the March 2025 Continuous Surface Connection Guidance. This would be demonstrated by relatively permanent water flow being present through the culvert as well as an ordinary high-water mark within the culvert.

The new, proposed rule states: “When preparing an approved jurisdictional determination, which is typically made at the request of a landowner or applicant, the agencies bear the burden of proof in demonstrating that an aquatic resource meets the requirements under the proposed rule to be jurisdictional or excluded. However, if the agencies do not have adequate information to demonstrate that a water meets the jurisdictional standards to be a WOTUS, the agencies would find such a water to be non-jurisdictional.“

This represents a substantial change in practice. Currently, if USACE and EPA lack information to complete an approved jurisdictional determination, it is the applicant’s responsibility to provide the required information.

As the extent of WOTUS continues to shrink, it will likely become more difficult to obtain a “federal nexus.” Projects with impacts to threatened or endangered species covered under the Federal Endangered Species Act (FESA) often find it more expeditious to meet their FESA requirements if a federal agency such as USACE consults with USFWS under Section 7 of FESA. However, this only occurs if a USACE permit is needed, creating a federal nexus and triggering a Section 7 consultation. Lacking such a federal nexus, a project proponent is left to consult directly with USFWS under Section 10 of FESA and is required to establish a habitat conservation plan, which can take years to complete before project approval is granted.

Waters of the state and wetlands that are non-jurisdictional WOTUS remain protected under state and local laws and regulations. At the state level, impacts to non-federally regulated waters and wetlands must comply with the Washington State Water Pollution Control Act (Chapter 90.48 RCW). Additionally, all shorelines and associated wetlands must comply with the Shoreline Management Act. However, the scope of the SMA is limited and only applies to waters meeting certain criteria. Local county and city codes include critical areas ordinances that provide protection and regulate activities that may impact critical areas including wetlands and other aquatic areas.

To enhance wetland protections, Washington’s Department of Ecology is proposing a new formal permitting program for state waters that are not WOTUS but are regulated under state law (State Waters Alteration Permit). The program aims to create a clear, formal process for permitting impacts to these state waters, which currently lack a formal program and are handled through administrative orders. Final rulemaking may take place sometime in 2026.

With one of the stronger wetland protection programs in the nation, the California legislature is attempting to preserve aquatic resource protections in light of the Sackett case, and the Proposed Rule. The Right of Clean Water Act, Senate Bill 609 (SB 601) would amend the state Porter Cologne Water Quality Control Act (Porter Cologne Act) to continue to regulate streams and wetlands that lost federal protection under the CWA due to Sackett. The stated goal of SB 601 is “to restore and retain protections afforded to certain waters of the state prior to May 25, 2023.”  If this legislation passes in 2026, it could further complicate environmental regulation in this state and offset deregulatory “gains” made at the federal level.

While the Proposed Rule means fewer Oregon landowners will need to obtain CWA permits, the state has its own Removal-Fill law (Chapter 196 — State Waters and Ocean Resources; Wetlands; Removal and Fill), that requires a permit for projects that add, remove, or move more than 50 cubic yards of material in wetlands and waters. Western Oregon has a relatively wet climate compared to many other states and is therefore unlikely to be as affected by RPW-related reductions in WOTUS coverage.

In the Sunshine State, many ephemeral streams and certain wetlands will likely no longer be under federal jurisdiction. However, the state has a very wet climate, so fewer aquatic resources will be affected by the Proposed Rule. Florida will have a greater role in regulating water bodies that fall outside the new federal definition, which aligns with the goal of strengthening state decision-making. Florida’s goal of pursuing renewed assumption of the 404 Permitting Program may lose its appeal if the Proposed Rule is finalized as federally regulated waters will have been further reduced.