Amistad International Reservoir (Rio Grande River Basin)
The Amistad International Reservoir is located in Val Verde County, Texas and the State of Coahuila, Mexico, with the dam approximately 12.8 river miles above Del Rio and Ciudad Acuña. The reservoir provides important flood control, water conservation, recreation, and electrical power production benefits. Penstocks were constructed at the time of dam construction in 1964-1969 and power generating plants were completed by the United States in 1983 and by Mexico in 1987.
The Dam of Amistad Reservoir is the second of the international multipurpose storage dams constructed during 1964-1969 on the Rio Grande by the United States and Mexico in accordance with the 1944 Water Treaty between the two countries. The dam is a concrete, gravity structure, with gated spillway, and flanked by an earth embankment section on each side. The total length of the dam is approximately 6.07 miles – 4.25 miles in Mexico and 1.82 miles in the United States. The concrete portion of Amistad Dam is 254 feet above the riverbed and is 2,182 feet long. Discharge over the crest of the spillway is controlled by 16 Tainter gates 50 feet wide and 54 feet high.
Maximum capacity of the reservoir is 5.29 million acre-feet; normal conservation and silt storage accounts for 3.275 million acre-feet. The conservation capacity is allocated 56.2% to the United States and 43.8% to Mexico. The dam (reservoir) is owned and operated by the International Boundary and Water Commission, United States and Mexico.