An Interstate Water Compact allocates water rights to particular bodies of water to the party states. "An interstate compact is an agreement between two or more states of the United States that is approved by those states’ respective legislatures, and, if required based on the subject matter of compact, consented to by the US Congress." Library of Congress June 2018 Interstate Compacts in the United States at 1.
Interstate compacts are negotiated contracts between two or more states. After the compact is negotiated, it must be approved by the legislatures of the states who are a party to the compact. Once approved by the state legislature it becomes a state statute. The US Constitution Article 1 Section 10 requires congressional approval of compacts between states. However, the US Supreme Court in 1893 held in Virginia v. Tennessee, 148 U.S. 503, consent is required only if it is “directed to the formation of any combination tending to increase of political power in the States, which may encroach upon or interfere with the just supremacy of the United States”. Interstate Compacts in the United States, Library of Congress June 2018 Id.at 2
This research guide looks at interstate water compacts within the United States, specifically Arizona, California, Colorado which fall within the western states of the United States where water is scarce.
S.J.D Candidate, Elisabeth Haub School of Law at Pace University