EPA and the Army Corps Seek Comment on Another WOTUS Alternative for Implementing Sackett v. EPA

On September 4, 2026, the U.S. Environmental Protection Agency (EPA) and the Department of the Army, U.S. Army Corps of Engineers (together, the agencies), announced a supplemental notice of proposed rulemaking (SNPRM) that requests additional public input on rules the agencies are considering to reflect the appropriate extent of federal Clean Water Act (CWA) jurisdiction over streams and wetlands. The SNPRM follows on the heels of roughly 220,000 comments the agencies received on their November 20, 2025 proposal to revise the definition of “waters of the United States” (WOTUS) in light of Sackett v. EPA, 598 U.S. 651 (2023), and it meaningfully expands the range of alternatives the agencies are considering for the final rule.

Background

The agencies previously issued a WOTUS notice of proposed rulemaking (NPRM) in November 2025, requesting feedback on changes aimed primarily at revising the WOTUS regulations to maintain consistency with the U.S. Supreme Court’s decision in Sackett. The agencies proposed to tie both “relatively permanent” waters and the “continuous surface connection” test for wetlands to the presence of surface water, “at least during the wet season.”

Commenters pushed back on the “wet season” concept from multiple directions—some arguing it swept in too much, others too little, and many questioning how it could be administered consistently across regions. The SNPRM adds a supplemental option that would replace the “wet season” trigger with a perennial-water standard and would insert a new regulatory definition of “perennial.” However, the SNPRM does not withdraw the November 2025 options; the agencies will consider the supplemental alternatives alongside the original proposal when developing the final rule. The agencies are now seeking comment on the proposed supplemental options.

The Supplemental Option for “Relatively Permanent” Waters (Tributaries)

Under the supplemental option described in the SNPRM, “relatively permanent” would be defined to mean “perennial bodies of water,” and “perennial” would mean “having standing or continuously flowing water every day of the year during ordinary conditions.” If adopted, jurisdiction over relatively permanent waters would be determined by using a perennial-water standard—rather than seasonal or intermittent waters—subject to tightly drawn exceptions:

• Anomalous events (e.g., drought or a non-regular dry spell) would not defeat federal jurisdiction over a water’s status as “relatively permanent.” The agencies are considering implementing this approach by treating only extreme (D3) and exceptional (D4) drought on the U.S. Drought Monitor as qualifying, extending no more than a continuous five-year period—after which the dry condition becomes the “new normal,” and the water is no longer jurisdictional.
• Non-anomalous events (e.g., low tide or a regularly occurring dry spell) that interrupt permanent flow would preserve federal jurisdiction only if the interruption lasts no more than a single period of up to 30 consecutive days in any given year. More than one such interruption in a year—even if each is shorter than 30 days—would render the feature intermittent or ephemeral rather than “relatively permanent,” and therefore it is non-jurisdictional.

The agencies frame this as a bright line that landowners can apply “by observation, without the need for any further analysis or professional consultation,” and one that responds to Sackett’s concern about property owners having to retain expensive consultants to assess jurisdiction. The agencies seek input on whether this perennial-water standard “most closely reflects the text of the Clean Water Act as interpreted in Sackett.”

The Supplemental Option for “Continuous Surface Connection” (Wetlands)

For wetlands, the SNPRM would define “continuous surface connection” to mean “perennial surface water in a wetland that is continuously connected with the surface water in the jurisdictional water such that it is difficult to determine where the jurisdictional water ends and the wetland begins.” This test would be subject to the same anomalous- and non-anomalous-event exceptions described above. Critically, only the portion of the wetland that is indistinguishably part of the jurisdictional water—by virtue of that perennial surface-water connection—would itself be jurisdictional. Federal jurisdiction would end where the indistinguishable surface-water condition ends.

The supplemental option rests on the agencies’ reading of Sackett as requiring an actual continuous surface water connection, reasoning that, if mere abutment sufficed, it would not be “difficult to determine where the ‘water’ ends and the ‘wetland’ begins.” The SNPRM also solicits comment on a further alternative that would treat Sackett’s “indistinguishability” concept as controlling and would remove the terms “adjacent” and “abutting” from the regulatory text altogether.

Impacts to Federal Jurisdiction

Putting aside the Sackett decision itself, the agencies’ supplemental option would likely narrow federal jurisdiction substantially in comparison to recent standards for determining WOTUS jurisdiction. The agencies’ discussion in the SNPRM reflects as much: they anticipate that most intermittent streams would not satisfy the supplemental “relatively permanent” definition, and the majority of wetlands that are currently considered jurisdictional as adjacent wetlands would not satisfy the supplemental “continuous surface connection” definition—because most wetlands do not contain perennial surface water. The agencies expect the largest reductions in the arid West, where intermittent streams drive much of the hydrology, and they anticipate that the CWA Section 404 dredge-and-fill permitting program would see the most significant programmatic changes, with projected reductions in the number of permits and the amount of required mitigation. Data limitations prevented the agencies from quantifying these effects, but they concluded that both the cost savings and the forgone benefits are larger under the SNPRM package than under the original November 2025 proposal.

Takeaways

The approach discussed in the SNPRM would effectuate a re-focusing of federal jurisdiction toward navigable and perennial waters that provide a more visible basis for jurisdiction than the sometimes complex tests for determining jurisdiction contained in past formulations. In relative terms, individual states and Tribes may assume a greater role as they choose to regulate (or not) waters that fall outside WOTUS jurisdiction. This could create greater certainty for parties assessing whether federal jurisdiction applies, while leaving more matters to state and Tribal regulation, resulting in greater variance among jurisdictions.

Overall:

• Streams and other tributary waters generally would have to be perennial—standing or continuously flowing every day of the year under ordinary conditions—to qualify as “relatively permanent.”
• Wetlands generally would have to contain perennial surface water that is continuously connected to surface water in an otherwise jurisdictional water to satisfy the Sackett continuous-surface-connection test.
• The agencies expressly acknowledge that most intermittent streams would not satisfy the requirements in the supplemental option for the proposed definition of “relatively permanent,” and the majority of wetlands currently jurisdictional as adjacent wetlands would not satisfy the supplemental definition of “continuous surface connection.”

What to Do Now

Comments on the SNPRM are due 30 days after the rule is published in the Federal Register. The agencies state that they are seeking comment only on the limited supplemental alternatives. Given the breadth of the proposed narrowing and reformulation of the jurisdictional standard, however, regulated entities, landowners, and project developers should assess how the perennial-water standard would affect features relevant to their operations and consider submitting comments during the 30-day window.

For background on the underlying proposal, see our earlier post, EPA and Army Corps Propose to Narrow Federal Jurisdiction Under the Clean Water Act.

This post is as of the posting date stated above. Sidley Austin LLP assumes no duty to update this post or post about any subsequent developments having a bearing on this post.