On September 4, 2026, the U.S. Environmental Protection Agency and the U.S. Department of the Army announced a Supplemental Notice of Proposed Rulemaking to gather public input on additional regulatory language defining Waters of the United States (WOTUS) to be considered in conjunction with the November 2025 proposed rule. This revision to the earlier proposed rule aims to implement the 2023 Supreme Court decision in Sackett et ux v. USEPA and seeks to establish clearer standards for determining which water bodies fall under federal jurisdiction.
The supplemental proposal “offers an additional opportunity for public engagement on a limited number of new regulatory alternatives, to be considered alongside those in the 2025 proposed rule.” Once the proposed rule is published in the Federal Register, the agencies will accept public comments for 30 days.
The additional regulatory options for consideration include a proposed definition of “perennial” and alternatives for defining “relatively permanent” and “continuous surface connection.”
The conceptual framework desired to be consistent with the Sackett case is to allow federal jurisdiction over only “relatively permanent waterbodies” tied to interstate and navigable waters and the territorial seas, and those specific adjacent wetlands that possess a “continuous surface connection” to them. The Supreme Court’s decision in Sackett stated that the Clean Water Act’s jurisdiction “extends only to those wetlands with a continuous surface connection to bodies that are waters of the United States in their own right, so that they are indistinguishable from those waters.” The agencies are currently seeking comment on only the following three formal terms and one alternative concept:
“Defining ‘perennial’ in the regulatory text to mean ‘having standing or continuously flowing water every day of the year during ordinary conditions’ or, alternatively, to mean ‘surface water flowing continuously year-round,’ consistent with the 2020 Navigable Waters Protection Rule.”
“Defining ‘relatively permanent’ to focus on those waters that are perennial bodies of water, except during anomalous events such as drought or dry spell or due to a non-anomalous event resulting in temporary interruption for no more than 30 consecutive days in any given year such as low tide or a regularly occurring dry spell.”
“Defining ‘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, with an exception for temporary interruptions in the surface water connection as the result of anomalous events such as drought or dry spell or a temporary interruption in the surface water connection lasting no more than 30 consecutive days in any given year as a result of non-anomalous events such as low tide or a regularly occurring dry spell.”
“As an alternative, revising the current category of jurisdictional waters for adjacent wetlands to include only wetlands that are indistinguishably part of a traditional navigable water, the territorial seas, a jurisdictional impoundment, or a jurisdictional tributary (for example, when surface water in a wetland 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 alternative would also result in deleting the definition of ‘adjacent.’”
These proposed alternative definitions eliminate reference to “wet season,” which the earlier draft definitions of “continuous surface connection” and “relatively permanent” referenced in the November 20, 2025 draft rule.
What’s Next?
These changes would apply only at the federal level and would not affect state jurisdiction. These definitions would effectively eliminate all ephemeral and intermittent streams from federal jurisdiction, along with all wetlands that do not exhibit surface water year-round (such as groundwater-driven wetlands with no visible surface water and runoff-driven wetlands that are dry for extended periods of the year).
The proposed rule is expected to be published in the Federal Register in the next few business days, at which time the formal 30-day public comment period will begin. Typically, EPA publishes Final Rules about 90 days later. Details about commenting can be found on EPA’s Waters of the United States website. For more information or to understand how this rulemaking could affect your projects, please contact your local Davey office.
This article has been adapted from Wetland Studies and Solutions, Inc.
FAQs for WOTUS Regulatory Updates
The proposed 2026 WOTUS update could further narrow which wetlands, streams, and other waters qualify as Waters of the United States under the federal Clean Water Act. The EPA and U.S. Department of the Army are considering new definitions for “perennial,” “relatively permanent,” and “continuous surface connection” following the Supreme Court’s Sackett decision. These definitions would help determine which water resources fall under federal jurisdiction. For land development, infrastructure, and municipal projects, the changes could affect wetland delineation, environmental permitting, and regulatory planning, although separate state and local requirements may still apply.
Ephemeral and intermittent streams and certain wetlands without a continuous, year-round surface water connection could fall outside federal Clean Water Act jurisdiction under the proposed WOTUS alternatives. The proposal would focus federal jurisdiction on relatively permanent waters and certain wetlands with a continuous surface connection to jurisdictional waters. This could exclude groundwater-driven wetlands without visible surface water and runoff-driven wetlands that remain dry for extended periods. However, exclusion from WOTUS does not necessarily mean a wetland or stream is unregulated. State and local wetland regulations may still apply and should be evaluated during wetland delineation, environmental due diligence, and permitting.
A “continuous surface connection” generally means a wetland has a surface water connection to a jurisdictional water, making it difficult to determine where the water ends and the wetland begins. Under one proposed 2026 definition, that connection would generally need to consist of perennial surface water, with limited allowances for temporary interruptions. Whether a wetland meets this standard could determine if it is subject to federal Clean Water Act jurisdiction. Evaluating hydrology and surface water connections during a wetland delineation can therefore be an important step in determining potential WOTUS jurisdiction and environmental permitting requirements.
WOTUS changes could affect whether wetlands, streams, and other aquatic resources on a development site require federal Clean Water Act permitting. If the proposed definitions are finalized, some resources that do not meet the new federal jurisdictional standards may no longer require federal authorization under WOTUS. However, developers should not assume that a resource is unregulated simply because it falls outside federal jurisdiction. State and local wetland regulations may impose separate requirements. Early wetland delineation, environmental due diligence, and regulatory review can help project managers identify applicable permitting requirements and incorporate environmental constraints into site planning.
The proposed 2026 WOTUS changes will not take effect unless the EPA and U.S. Department of the Army complete the federal rulemaking process and issue a final rule with an effective date. The September 2026 supplemental proposal adds regulatory alternatives to those introduced in November 2025 and will be subject to a 30-day public comment period after publication in the Federal Register. Until a final WOTUS rule becomes effective, municipalities, developers, and project managers should continue following current federal requirements and applicable state and local regulations when conducting wetland delineations, environmental assessments, and permitting reviews.
