While WOTUS serves as the jurisdictional foundation of the Clean Water Act (CWA), the statute does not define the term. Since the CWA's enactment in 1972, determining the scope of WOTUS—and, in turn, the reach of federal regulatory authority—has remained a persistent and challenging issue in environmental law. By defining "navigable waters" only as "waters of the United States," Congress left it to the U.S. EPA, the U.S. Army Corps, and the courts to interpret a term with significant implications for federal-state authority, environmental protection, and private property rights.
The definition of WOTUS has evolved through a combination of agency action and Supreme Court decisions, including Rapanos v. United States, and Sackett v. EPA (2012) (Sackett I ). These decisions have shaped how the agencies interpret jurisdiction, particularly with respect to wetlands. The split Rapanos decision introduced competing analytical frameworks, further contributing to longstanding uncertainty.
In this episode, Professor Royal Gardner will provide a high-level overview of these developments, placing recent changes in context and offering insight into the current and future scope of federal jurisdiction under the CWA.