The firm authored an amicus brief for the hydroelectric industry in Los Angeles County Flood Control District v. Natural Resources Defense Council, Inc., No. 11-460, before the U.S. Supreme Court. The case involved a U.S. Court of Appeals for the Ninth Circuit decision holding that pre-polluted water originating from a navigable river and passing through a “man-made construction” into the natural river below is a “discharge of a pollutant” under the Clean Water Act (CWA). The Ninth Circuit’s decision raised concerns for the hydropower industry because dams are man-made constructions in navigable waters that discharge water downstream, and the decision suggested, contrary to well-established precedent, that dams could become subject to National Pollutant Discharge Elimination System (NPDES) permitting under section 402 of the CWA. The Supreme Court unanimously reversed the Ninth Circuit decision, holding that the flow of water from an improved portion of a navigable waterway into an unimproved portion of the same waterway does not qualify as a “discharge of a pollutant” under the CWA. The Court’s decision preserves long-standing precedent that hydropower dams are generally not subject to NPDES permits. The firm’s amicus brief urged the result reached by the Court.