The Supreme Court unanimously ruled that challenges to the Waters of the United States (“WOTUS”) Rule, which defines the jurisdictional reach of the Clean Water Act, must be resolved in federal district courts and not the courts of appeals as the United States had argued. See National Association of Manufacturers v. Department of Defense, Slip Op. (Jan. 22, 2018).

The Court’s decision creates significant uncertainty regarding the jurisdictional reach and application of the Clean Water Act, which regulates the discharge of pollutants into “waters of the United States” through programs regulating activities in wetlands, NPDES discharge permits, and the regulation of stormwater. The WOTUS Rule adopts a broad and controversial interpretation of which waters, and thus which discharges, are regulated under the act.