Course of the Colorado River Lake Mead, formed by the -high Hoover Dam about southeast of Las Vegas, Nevada, is the largest reservoir in the United States with a full capacity of and a water surface of nearly . However, the lake has not been full for many years due to a combination of drought and increased water usage by Colorado River Basin states. Situated in the Lake Mead National Recreation Area, Lake Mead is a popular recreation site – visited by almost 8 million people a year – and a critical source of water for the Las Vegas metropolitan area, Central Arizona and Southern
Course of the Colorado River through the desert Lower Colorado River Valley (LCRV), where its character changes significantly from fast-flowing whitewater to a low gradient braided stream with a wide floodplain. Here, the Colorado River ranges in width from and from in depth. It becomes a losing stream, with a gradual reduction in volume both due to evaporation in the hot desert climate and massive diversions for irrigation, urban areas, industry and thermo-electric power generation. The average flow rate of at Davis Dam diminishes to just at the Mexican border. At Needles, California the Colorado is crossed by Interstate 40; shortly downstream it passes the