How is Las Vegas getting enough water for its expanding population? Most of it comes from Lake Mead on the Colorado River. The Colorado River provides water for Las Vegas, as well as Phoenix, Los Angeles, and San Diego. As the populations of all of these cities continue to grow, water demand also increases. However, less snowpack in the mountains in recent years has reduced the river’s flow and thus the amount of water stored in the reservoir.

Landsat images starting in 1972 show the changing water level of the lake. In June 2016, Lake Mead’s water level fell to 1,071 feet above sea level. The level hasn’t been this low since the lake began filling in the 1930s. The January 2016 level of just under 1,084 feet above sea level was the lowest January level on record since the lake began filling. In September 2020, the lake was reported to be 40% full.

The drop in lake level isn’t even as apparent as it might otherwise be because of the steep topography in the region. Lake Mead is inside a canyon environment, so the drastic reduction in lake level does not equate to as drastic of a reduction in surface area, even though the surface area reduction is quite noticeable.