Interstate Compact
A contract between two or more states, or between states and a foreign government, to address a common problem or manage shared resources. Under the Compact Clause, compacts that increase state political power require congressional consent.
A contract between two or more states, or between states and a foreign government, to address a common problem or manage shared resources. Under the Compact Clause, compacts that increase state political power require congressional consent.
Example: The Colorado River Compact of 1922 is a historic agreement among seven western states that allocates the rights to the waters of the Colorado River.
Common misconception: States can make any agreement they want without federal oversight. While minor administrative agreements are allowed, any compact that alters the political balance of power or affects federal authority requires the explicit consent of Congress.
Sources: https://constitution.congress.gov/browse/article-1/section-10/ — Constitution Annotated, Art. I, §10, cl. 3 (Compact Clause: "No State shall, without the Consent of Congress… enter into any Agreement or Compact with another State"); https://www.usbr.gov/lcr/relationship.html — Bureau of Reclamation, official Colorado River Compact (1922) resource page