The building of the dam created Lake Mead, which is still the largest reservoir in the United States, containing enough water to flood the entire state of New York with one foot of water. The Hoover Dam also signifies the first time the Colorado River was controlled for human use, providing a dependable supply of water for farmers in Nevada, California and Arizona, and also providing an inexpensive form of electricity to Los Angeles, San Diego, Phoenix, Las Vegas and many other towns and cities. Water from the Colorado River has always been necessary to sustain life in the desert areas of southwestern United States, and Lake Mead contains enough water to supply nearly 29 million households with water each year. Without controls, such as man-made dams, the Colorado River would flood in some years as to wipe out entire towns or cities. In one such flood, just after the turn of the last century, the Salton Sea in southern California was created.
Dams also allow water to be contained and saved for use in dry years.
Every state in the United States helped in the building of the Hoover Dam. During the building between 1931 and 1934, supplies, materials and 16,000 depression-era workers came from every part of the country. Many of these workers brought their entire families to live nearby. Today, the Hoover Dam and the Lake Mead Reservoir are open to the public. The Hoover Dam Visitors' Center provides an exhibit gallery where you can learn more about the building of the Hoover Dam, and guided tours are also available.