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
Glen Canyon Dam Sea. After this catastrophe, California and Arizona began to call for a dam to control the tempestuous river. In 1922, six U.S. states signed the Colorado River Compact to officially allocate the flow of the Colorado River and its tributaries. Each half of the Colorado River Basin – the Upper Basin, comprising Colorado, New Mexico, Utah and Wyoming – and the Lower Basin, with California and Nevada – was allotted of water annually, and a treaty between the U.S. and Mexico was signed in 1944 allocating to Mexico. The third lower basin state, Arizona, did not ratify the Compact until