Evolution in the Binational Management of the Rio Grande/Rio Bravo River

The United States and Mexico share about 2,000 km (approximately 1,250 miles) of a river called Rio Grande in the USA and Rio Bravo in Mexico (RG/RB), a transboundary river in an arid and semi-arid region. Under the terms of the binational 1944 Treaty for the “Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande,” Mexico is required to deliver 431.7 mcm (350,000 acre-ft) of water annually to the United States on the RG/RBH, in cycles of 5 years. Treaty obligations between the two countries on water deliveries have been difficult to fulfill in the past 25 years, in part due to drought and different interpretations of the Treaty. Surface water quality, including bacterial contamination and elevated salinity levels, has been a major concern. This paper discusses trends in RG/RB water quantity deliveries and water quality as well as Mexican and USA efforts to address disagreements together.