The commission and the treaty behind Mexico's Rio Bravo water accounting

Background

Mexico's announcement that it had completed the first year of cycle 37 of Rio Bravo water deliveries rests on a long-standing bilateral arrangement. The treaty is the Tratado sobre Distribución de Aguas Internacionales entre México y los Estados Unidos, signed on 3 February 1944 and known as the 1944 Water Treaty. It is administered by the Comisión Internacional de Límites y Aguas entre México y Estados Unidos (CILA), whose United States section is the International Boundary and Water Commission. Under Articles 4, 8 and 9 of the treaty, the commission accounts for the waters of the Rio Bravo between Fort Quitman and the Gulf of Mexico, and Article 9-J requires it to keep the water records. CILA operates hydrometric and climatological stations, gathers water use data from both countries and estimates reservoir storage each week. Deliveries are counted in cycles: cycle 35 ran from 25 October 2015 to 24 October 2020, and cycle 36 began on 25 October 2020. The two main international storage works on the river are La Amistad dam, 923.63 km upstream of the Gulf of Mexico, and Falcón dam, 442.95 km upstream.