Imperial Dam and Desilting Works span the Colorado River 18 miles northeast of Yuma, Arizona. The purpose of the dam is to raise the water surface 25 feet and provide controlled gravity flow of water into the All-American and Gila Gravity Main Canals. The desilting works remove most the sediment carried by the Colorado River to prevent clogging of the canals and subsequent extensive maintenance.
Imperial Dam is a reinforced concrete structure of the monolithic slab-and-buttress type consisting of an overflow weir, canal headworks at each end of the dam, and a sluiceway between the All-American Canal Headworks and overflow weir. The dam is 3,475 feet long, including a 510-foot rockfill dike at the Arizona end. The 1,198-foot-long overflow weir, in conjunction with the California Sluiceway, is designed to pass a maximum flood of 185,000 cubic feet per second, not including any diversions to the canal systems.