Colorado River Aqueduct

The Colorado River Aqueduct carries water 242 miles (389 km) across the Mojave Desert, from Lake Havasu on the Arizona border to Lake Mathews in Riverside County, supplying a large share of Southern California's drinking water. Built by the Metropolitan Water District of Southern California, it was one of the great public works of the Depression: about 30,000 workers spent eight years blasting tunnels through mountains and laying canals and siphons across the desert, and water first flowed in 1939.

Because the desert lies higher than the river, the aqueduct depends on five pumping plants that lift the water more than 1,600 feet in total over the mountains in its path, an enormous engineering and energy undertaking. It can carry about 1,600 cubic feet (45 m³) of water per second. The American Society of Civil Engineers ranked it among the seven modern civil engineering wonders in 1955, and with the Colorado River now in long-term drought, its future flows depend on how the basin states share a shrinking river.

• The Mojave Desert
  The driest desert in North America crosses
• The Colorado River
  The river that carved the Grand Canyon fed by
• California
  The most populous U.S. state, admitted 1850 located in
• Hoover Dam
  The concrete colossus on the Colorado related
• Los Angeles
  The second-largest U.S. city, on the Southern California coast supplies