Los Angeles County Flood Control District v. Natural Resources Defense Council, Inc., 568 U.S. ___ (2013), is a United States Supreme Court case in which the Natural Resources Defense Council and Santa Monica Baykeeper challenged the Los Angeles County Flood Control District (District) for violating the terms of its National Pollutant Discharge Elimination System (NPDES) permit as shown in water quality measurements from monitoring stations within the Los Angeles and San Gabriel Rivers. The Supreme Court, by a unanimous 9-0 vote, reversed and remanded the Ninth Circuit's ruling on the grounds 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 Clean Water Act.