The Colorado River Aqueduct is a 242-mi (392 km) water conveyance in southern California in the United States. The aqueduct diverts water from the Colorado River at Lake Havasu on the California-Arizona border west across the Mojave and Colorado deserts to the east side of the Santa Ana Mountains. The aqueduct is operated by the Metropolitan Water District of Southern California (MWD) as one of the primary sources of drinking water in southern California.
The aqueduct begins at the Parker Dam on the Colorado southeast of Lake Havasu City, Arizona. It crosses the southern Mojave Desert, skirting around several small mountain ranges and the southern edge of Joshua Tree National Park. It 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 whence it is distributed to multiple communities in the MWD region.
The aqueduct consists of two reservoirs, five pumping plants, 63 miles (101 km) of canals, 92 miles (148 km) of tunnels, and 84 miles (135 km) of buried conduit and siphons. Its capacity is 1.3 million acre-feet (1.6 km³) per year.
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. 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 "wonders" of the American engineering world.
Adapted from the Wikipedia article, "Colorado River Aqueduct" http://en.wikipedia.org/wiki/Colorado_River_Aqueduct, used under the GNU Free Documentation License.