AMERICAN DAM. American Dam is located on the Rio Grande at El Paso, 140 feet north of where the Mexican border leaves the river and goes overland toward the Pacific Ocean. On May 21, 1906, the United States and Mexico signed a treaty for "an equitable distribution of the waters of the Rio Grande." To carry out the treaty, the United States Bureau of Reclamation built Elephant Butte Dam on the Rio Grande at Truth or Consequences, New Mexico, 125 miles north of El Paso. Impounding the water at the dam guaranteed Mexico a maximum of 60,000 acre-feet of Rio Grande irrigation water a year, available on demand, to be delivered at the main irrigation canal in Ciudad Juárez, Chihuahua, known as the Acequia Madre. The canal's mouth is two miles downstream from the international border. The remainder of the water would be used by American farmers in the ninety-mile-long El Paso valley. In times of drought both Mexican and American shares would be reduced on a percentage basis.
The system did not provide a way for the United States to allot Mexico its rightful portion and keep the rest. As a result, Mexico took its share first and channeled the remainder into the Franklin Canal for the farms in the El Paso valley. According to some American estimates this permitted Mexico to siphon off up to three times its portion of irrigation water. Responding in 1935, Congress authorized two diversionary projects, the American Dam and the American Canal. The dam caught the water in New Mexico short of the international border, measured Mexico's share and allowed it to continue to the Acequia Madre, and diverted everything else into the American Canal, a two-mile feeder leading to the Franklin Canal. The project has proved a successful solution to the problem of dividing the waters.
J. C. Day, "Urban Water Management of an International River: The Case of El Paso-Juarez," Natural Resources Journal 15 (July 1975).