All-American Canal, 80 mi (129 km) long, SE Calif.; part of the federal irrigation system of the Hoover Dam. Built between 1934 and 1940 across the Colorado Desert, the canal is entirely within the United States and replaces the Inter-California Canal, which passes through Mexico. The Imperial Dam, NE of Yuma, Ariz., diverts water from the Colorado River into the All-American Canal, which runs W to Calexico, Calif. Smaller canals move water into the Imperial Valley; the Coachella Canal branches NW to the Coachella Valley. This canal system irrigates more than 630,000 acres (254,961 hectares) and has greatly increased crop yield in the area; however, problems of drainage and salinity exist.