The question of which waters are federally regulated under the Clean Water Act (CWA) has confused permittees, property owners, states, federal agencies, and courts for decades. The CWA gives the U.S. Environmental Protection Agency (EPA) and Army Corps of Engineers (Corps) authority to regulate “navigable” waters. “Navigable” waters are further defined in the statute as “the waters of the United States,” or WOTUS. But the statute does not specifically define WOTUS, instead giving EPA and the Corps the responsibility to develop this definition through notice and comment rulemaking.
A central tenet of the CWA is cooperative federalism – the federal government and states must work together. Any waters not regulated by the federal government are regulated by the states and local municipalities. On multiple occasions, the Supreme Court has said that both the CWA and U.S. Constitution limits the federal government’s role over the use of public and private land near bodies of water.
In 2015, EPA and the Corps finalized a new rule that defined WOTUS broadly to include nearly all waters on the landscape, and even areas that ordinarily are dry land. This rule was immediately halted and never went into effect in much of the country. Numerous courts also deemed the 2015 rule unlawful.
In response, the agencies worked to revise the definition of WOTUS in a way that was both easily understood by permittees on the ground and legally defensible. After extensive public comment periods and stakeholder input, the agencies published and finalized the Navigable Waters Protection Rule (NWPR) in 2020. The NWPR is a more streamlined rule that provides landowners, farmers, and small businesses the clarity they need to operate with confidence and comply with the CWA. It includes four clear categories of jurisdictional waters, . The NWPR regulates the nation’s navigable waters and the core tributary systems that provide perennial or intermittent flow into them. The rule is currently in effect nationwide and thus, stakeholders have been relying on and implementing the definitions and terms therein since mid-2020.