Amistat International Reservoir is a 26,300 hectare (65,000 acre) multi-purpose reservoir that impounds the Rio Grand River. The Amistad Reservior was created under the provisions of the Water Treaty of 1944 between the United States of American and Mexico and 22 USC 227d 13-16, Storage Dam- US and Mexico, approved July 7, 1960. The river serves its purpose to the United States as water storage for municipal industrial and agricultural uses in south Texas.