By: John B. King
The Supreme Court’s ruling in Sackett v. EPA continues to dominate discussions regarding the scope of jurisdiction over adjacent wetlands. Now, the Corps and EPA seek to codify that ruling into the regulatory definition of ‘waters of the United States.’
In Sackett, the Supreme Court adopted Justice Scalia’s opinion in its prior Rapanos decision. It held that the Clean Water Act extends only to those wetlands that are as a practical matter indistinguishable from waters of the United States. The Corps must establish first, that the adjacent body of water constitutes ‘waters of the United States’ (i.e., a relatively permanent body of water connected to traditional interstate navigable waters) and second, that the wetland has a continuous surface connection with that water, making it difficult to determine where the water ends and the wetland begins. Sackett v. EPA, 143 S.Ct. 1322, 1341 (20243).
The Corps and EPA seemed reluctant to strictly adhere to the Sackett ruling. They did, however, amend the definition in September 2023 (the so-called Conforming Rule) in an attempt to align the regulatory definition of ‘waters of the United States’ with Sackett. The Conforming Rule removed the ‘significant nexus’ language from the rule and defined ‘adjacent’ to mean ‘having a continuous surface connection.’
The Trump Administration has taken several additional actions to adhere to Sackett. In March 2025, a joint Memorandum to the Field was issued. Among other things, it makes clear that “adjacent” means “physically abutting.” Thus, adjacent wetlands are “those that directly ‘abut’ covered waters.’” It goes on to state that “unless a wetland has a continuous surface connection – directly abutting a requisite jurisdictional water – it cannot be determined to be jurisdictional as an adjacent wetland.” Further, in April 2025, additional guidance was issued regarding the proper interpretation of continuous surface connection.
The latest action by the Trump Administration is the issuance of a proposed rule which revisits the
regulations defining the scope of jurisdiction under the Clean Water Act in light of Sackett. 90 Fed. Reg. 52498 (Nov. 20, 2025). The actual revisions are minor but go a long way to incorporating the limitations on jurisdiction imposed by Sackett. The proposed rule does so by adding definitions in line with Sackett.
‘Continuous surface connection’ was defined to mean “having surface water at least during the wet season and abutting (i.e., touching) a jurisdictional water.” ‘Relatively permanent’ was defined to mean “standing or continuously flowing bodies of surface water that are standing or continuously flowing year-round or at least during the wet season.” ‘Tributary’ was defined to mean “a body of water with relatively permanent flow, and a bed and banks, 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.”
These proposed definitions provide context to the current regulation in which the agencies have jurisdiction only over wetlands adjacent to traditional navigable waters and those wetlands adjacent to relatively permanent, standing or continuously flowing bodies of water (i.e., impoundments and tributaries) with a continuous surface connection to those waters. In general, then, jurisdiction attaches only to wetlands that actually touch or abut a relatively permanent body of water and wetlands that have a continuous surface connection, as defined, with a relatively permanent body of water.
Of course, there are those who oppose the proposed rule even though it purports to adopt the Sackett ruling. For example, one group argued that the proposed rule is inconsistent with the objectives of the Clean Water Act to maintain the chemical, physical, and biological integrity of the nation’s water. However, in Sackett, the Supreme Court interpreted the wording of the Clean Water Act and the agencies cannot simply ignore the ruling and regulate beyond the scope of the statutory duty, as interpreted by the Supreme Court.
When the final rule is issued, there will be challenges and litigation. It will be several years before the courts issue a final ruling. However, in terms of simply following the Supreme Court’s interpretation and direction, opponents may have a difficult time convincing a federal court that the agencies did not adhere to the law as stated in Sackett.
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