Lake Mead, in Arizona and Nevada, is the largest reservoir in the United States and part of the Colorado River system, which supplies water to seven U.S. states and part of Mexico, including one third of the water used in Southern California. It also supplies 30 Tribal Nations.

At the end of last year, experts predicted that, due to drought and heavy demand for water, Lake Mead was just two years shy of dead pool, when water levels drop below the point at which it can flow downstream of the reservoir.