Parker Dam spans the Colorado River between Arizona and California, 155 miles downstream from Hoover Dam. Built between 1934 and 1938 by the Bureau of Reclamation, Parker Dam is operated with Hoover and Davis Dams to bring water and power benefits to residents of the lower Colorado River Basin.
Parker Dam is the deepest dam in the world; 73 percent of its structural height of 320 feet is below the original riverbed. Two-hundred and thirty-five feet of the Colorado riverbed was excavated before concrete was placed for the dam's foundation. Only about 85 feet of the dam is visible; the dam's superstructure rises another 62 feet above the roadway across the top of the dam.
Parker Dam's primary purpose is to provide reservoir storage for water to be pumped into the Colorado River and Central Arizona Project Aqueducts. Lake Havasu, the reservoir behind Parker Dam, is about 45 miles long and can store nearly 211 billion gallons of water.
Lake Havasu provides clear, desilted water for the Colorado River Aqueduct and serves the Central Arizona Project. Parker Dam was constructed with funds advanced by the Metropolitan Water District of Southern California. Since 1941, the Colorado River Aqueduct has delivered water from Lake Havasu behind Parker Dam to the Los Angeles metropolitan area. The Colorado River Aqueduct is also tapped by the San Diego Aqueduct, which takes water to that city's water system as well.