History of Arizona programs. Federal money started arriving with the Federal Emergency Relief Committee in 1930. Different agencies promoted aid to the unemployed, tuberculosis patients, transients, and illegal immigrants. The money ran out by 1931 or 1932, and conditions were bad until New Deal relief operations began on a large scale in 1933. Construction programs were important, especially Hoover Dam (originally called Boulder Dam), begun by President Herbert Hoover. It is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border with Nevada. It was constructed by the Federal Bureau of Reclamation between 1931 and 1936. It operationalized
Colorado River basin. Phoenix in Arizona and Las Vegas in Nevada are the largest metropolitan areas in the watershed. Population densities are also high along the lower Colorado River below Davis Dam, which includes Bullhead City, Lake Havasu City, and Yuma. Other significant population centers in the basin include Tucson, Arizona; St. George, Utah; and Grand Junction, Colorado. Colorado River basin states are among the fastest-growing in the U.S.; the population of Nevada alone increased by about 66 percent between 1990 and 2000 as Arizona grew by some 40 percent. The Colorado River basin shares drainage boundaries with many other major watersheds