The U.S. Supreme Court’s recent decision in Sackett v. Environmental Protection Agency interprets the term “waters of the United States” (WOTUS) and federal jurisdiction under the Clean Water Act (CWA) in a way that runs counter to a half-century of administrative guidance and regulatory enforcement. 

The test the court sets forth to determine whether wetlands are WOTUS harkens back to historical notions of federal jurisdiction of navigable waters as channels of commerce. The decision will have the present practical effect of deregulating millions of acres of previously protected wetlands throughout the country, though the scope of jurisdiction remains unclear and untested.