Following years of administrative rulemaking and litigation, the U.S. Supreme Court published a much-anticipated decision interpreting what is a water of the United States (WOTUS) under the Clean Water Act (CWA). On May 25, 2023, the U.S. Supreme Court issued its decision in Sackett v. Environmental Protection Agency, 598 U.S. __ (2023). The Court determined that only wetlands with a “continuous surface connection” to a WOTUS are subject to CWA ‎jurisdiction. The decision restricts U.S. agencies’ ability to regulate certain types of wetlands and ‎water bodies‎. This is contrary to the Environmental Protection Agency (EPA) and Army Corps of Engineers (Corps) rule interpreting WOTUS to include wetlands that are “adjacent” (but not necessarily touching) wetlands.


In 1972, Congress enacted the CWA and President Nixon signed it into law. The CWA regulates the discharge of pollutants to “navigable waters,” which are defined to mean “waters of the United States, including the territorial seas.”[1] The term “waters of the United States” is not further defined in the CWA. This has created various regulatory and judicial interpretations of the term and resulted in different agencies’ determinations as to the scope of their authority over wetlands. The scope of jurisdiction is relevant for farmers, ranchers, timberland owners, homebuilders, developers, and others because if a proposed project or development includes jurisdictional waters or wetlands, the proposed project or development will likely be required to obtain approval from the Corps before proceeding.

Given the importance of the definition of WOTUS, as it relates to wetlands, there has been extensive litigation about what the EPA considers a WOTUS. We previously discussed the background and significance of the WOTUS definition here. In fact, effective March 20, 2023, the EPA and Corps had adopted a new rule defining WOTUS, as further explained here, but the decision in Sackett v. EPA effectively nullifies the EPA’s and Corps’ rule.

Sackett v. EPA

The Sackett case has a lengthy history. In 2004, the Sacketts acquired a lot near Priest Lake in Idaho. They began backfilling their property in anticipation of building a home, but the EPA sent them a compliance order informing them that the backfilling violated the CWA because the existing wetlands on their property were near a ditch that fed into an unnamed tributary on the other side of a 30-foot road, which fed into a creek, which in turn fed into Priest Lake, which is a WOTUS. The Sacketts sued the EPA alleging that the wetlands on their property were not part of a ­­WOTUS. After years of litigation in federal district court in Idaho and the Ninth Circuit Court of Appeals, the U.S. Supreme Court decided in favor of the Sacketts.

The Court held that consistent with its 2006 decision in Rapanos v. U.S., [2] “waters” could only be read to include wetlands that are “as a practical matter indistinguishable from waters of the United States.”[3] The Court specified that for a wetland adjacent to a WOTUS to fall within the jurisdiction of the CWA, first, the body of water adjacent to the wetland must constitute a WOTUS (a relatively permanent body of water connected to traditional interstate navigable waters). Second, the wetland must have a “continuous surface connection with the water that is a WOTUS such that it is difficult to determine where the “water” ends and the “wetland” begins. However, the Court did acknowledge that a water may be a WOTUS even if some “temporary interruptions in surface connection…occur because of phenomena like low tides or dry spells.”[4]

Looking Ahead

In the wake of Sackett, certain wetlands will no longer be regulated as a WOTUS under the CWA. It will be important to determine how the decision may affect a proposed project or development, particularly whether, in light of the decision, there is a wetland that is a WOTUS on a property that requires approval from the Corps prior to development.

Both Washington and Oregon have broader authority to regulate waters of the state than federal counterparts have to regulate waters under the CWA. Both states will continue to depend heavily on their own water quality statutes and regulations to regulate waters of the state that might not be subject to CWA jurisdiction.

In response to the Sackett decision, the Washington State Department of Ecology issued a statement indicating that wetlands that are no longer considered part of a WOTUS under the decision will retain protection as waters of the state.

In Oregon, the Department of State Lands and the Department of Environmental Quality will continue to regulate the addition of pollutants and dredged and fill material to waters of the state, which include wetlands.

However, for any person or company filling a wetland in Washington or Oregon, if the wetland does not have a continuous surface connection to a WOTUS, it may only require a state permit.

This article summarizes aspects of the law and does not constitute legal advice. For legal advice for ‎your situation, you should contact an attorney.

[1] 33 U.S.C. § 1362(7).
[2] Rapanos v. U.S., 547 U.S. 715 (2006).
[3] Sackett v. Environmental Protection Agency, 598 U.S. at *21.
[4] Id.

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