Drowning in Aridity: Lake Mead's Grim Reality Lake Mead, the largest reservoir in the United States, has fallen to its lowest level since its construction in the 1930s. The record low water mark of 1,040.
5 feet above sea level at Hoover Dam on the Arizona Nevada border is a dire warning sign for the region's water woes.
The Colorado River Basin system supplies drinking water to over 40 million people across seven states and parts of Mexico.