History of California 1900–present conduit and siphons. Average annual throughput is . Davis Dam is located on the Colorado River about downstream from Hoover Dam. Davis Dam stretches across the border between Arizona and Nevada and impounds the Colorado River to form Lake Mohave. The United States Bureau of Reclamation owns and operates the dam, which was completed in 1951. Davis Dam is a zoned earth fill dam with a concrete spillway, in length at the crest, and high. The earth fill dam begins on the Nevada side, but it does not extend to the Arizona side. Instead, there is an inlet formed by
Colorado River beyond Yuma, Arizona, and the confluence with the intermittent Gila River – which carries runoff from western New Mexico and most of Arizona – before defining about of the Mexico–United States border. At Morelos Dam, the entire remaining flow of the Colorado is diverted to irrigate the Mexicali Valley, among Mexico's most fertile agricultural lands. Below San Luis Río Colorado, the Colorado passes entirely into Mexico, defining the Baja California–Sonora border; in most years, the stretch of the Colorado between here and the Gulf of California is dry or a trickle formed by irrigation return flows. The Hardy River provides