History of Lake Mead & Hoover Dam

The unrelenting drought that has plagued the Colorado River Basin for more than a decade is redefining the water resources millions of people depend on, perhaps even ushering in a new reality for water in the west. The water inflow into the Colorado River has been below average for 13 out of the past 16 years, with average water inflow since 2000 just 79 percent of the previous 30-year average. The period 2000-2015 had the lowest water availability of any 16-year period in the last 60 years.

As a result, since 2000 Lake Mead water surface elevation has dropped over 143 feet, going from full to only 38 percent of the total storage capacity. The lower lake level impacts everything from launching boats to lake ecosystems. The net water loss is nearly six trillion gallons of water. The combined reservoirs of the Colorado River overall have gone from being nearly full to containing only approximately 50 percent of overall storage capacity.

While the Colorado River has been affected by previous droughts, a warming climate is predicted to alter the water cycle in new ways. Long range climate predictions are for warmer winter temperatures in the Southwest, less snowpack in the Rocky Mountains, and less melted snow able to find its way into the Colorado River.

Projections for the future indicate that an imbalance in the system will persist: there will not be enough water naturally coming into the system to replenish what we are removing. This has prompted water managers from the seven Colorado River Basin states as well as Department of the Interior to develop a comprehensive study looking in detail at water supply and demand over the next 50 years. That study found that by 2060 the use demand on the Colorado River will be greater than the projected supply by 3.2 million acre feet (that’s enough water for approximately 16 million people for one year).