One of the Seven Engineering Wonders of American Engineering
Early detailed map and brochure showing Southern California and highlighting the route of the Colorado River Aqueduct during its construction.
The aqueduct begins near Parker Dam on the Colorado southeast of Lake Havasu City, Arizona. It crosses the southern Mojave Desert, then enters the Coachella Valley north of the Salton Sea and flows northwest along the Little San Bernardino Mountains. It crosses the San Jacinto Mountains west of Palm Springs and terminates at Lake Mathews in western Riverside County, from where the water is distributed to multiple communities in the Metropolitan Water District.
The aqueduct was constructed between 1933-1941 by the MWD to ensure a steady supply of drinking water to Los Angeles and now serves Southern California communities from Ventura County to San Diego County. Water first flowed in the aqueduct on January 7, 1939 when the intake pumps at Lake Havasu began operation to fill the first of the reservoirs in the system in Gene Basin. Originally conceived by William Mulholland and designed by Chief Engineer Frank E. Weymouth of the MWD, it was the largest public works project in Southern California during the Great Depression. The project employed 30,000 people over an eight-year period and as many as 10,000 at one time.
The construction of the aqueduct is widely credited as being a principal reason for the industrial growth of the region during World War II and the following decades. In 1992, the aqueduct was recognized by the American Society of Civil Engineers (ASCE) as one of the "Seven Engineering Wonders of American Engineering".