Argument analysis: Justices press advocates on Rio Grande Compact and United States’ treaty obligations to Mexico

Yesterday, the Supreme Court heard oral argument in two original jurisdiction disputes among states in which key federal water agencies are involved. In the first case, the United States Department of the Interior’s Bureau of Reclamation operates the Rio Grande Project, which regulates the flows of the Rio Grande River, affecting the water rights of users in Texas, Colorado and New Mexico and delivering water from Elephant Butte Reservoir in New Mexico to the Republic of Mexico. The congressionally approved Rio Grande Compact of 1938 apportioned water rights among these states.