Sharing the Colorado River and the Rio Grande: Cooperation and Conflict with Mexico [December 12, 2018] [open pdf - 2MB]
"The United States and Mexico share the waters of the Colorado River and the Rio Grande. A bilateral water treaty from 1944 (the 1944 Water Treaty) and other binational agreements guide how the two governments share the flows of these rivers. The binational International Boundary and Water Commission (IBWC) administers these agreements. Since 1944, the IBWC has been the principal venue for addressing river-related disputes between the United States and Mexico. The 1944 Water Treaty authorizes the IBWC to develop rules and to issue proposed decisions, called minutes, regarding matters related to the treaty's execution and interpretation."
CRS Report for Congress, R45430
Congressional Research Service: https://crsreports.congress.gov/