In addition to water loss due to an intense multi-year drought, the USGS and Bureau of Reclamation report found
Between 1963 and 2018, Lake Powell experienced an average annual storage capacity loss of about 33,270 acre feet or 11 billion gallons per year.
This water is enough to fill the Reflecting Pool on the National Mall about 1,600 times.
According to the report, the storage capacity of the reservoir is shrinking due to sediment coming from the Colorado and San Juan rivers. These sediments settle to the bottom of the reservoir and reduce the total amount of water that the reservoir can hold.
As of Monday, Lake Powell was about 25% full, according to the Bureau of Reclamation.
This is bad news for the region, which is already facing water shortages and severe wildfires due to the drought. Drought experts at the National Oceanic and Atmospheric Administration said last week that these conditions are expected to at least persist, if not worsen, in the coming months.
Lake Powell is an important reservoir in the Colorado River basin. Both Lake Powell and nearby Lake Mead, the country’s largest reservoir, have dried up at an alarming rate. In August, the federal government announced a water shortage for the first time in the Colorado River after water levels in Lake Mead fell to an all-time low, leading to mandatory water cuts in states in the southwest that began in January.
And last week, Lake Powell dipped below the critical threshold of 3,525 feet above sea level, raising more concerns about the water supply and hydroelectric power generation that millions of people in the West depend on for electricity.
The significance of declining water supplies along the Colorado River cannot be overestimated.
The system provides water to more than 40 million people living in seven western states and Mexico. Lakes Powell and Mead provide much-needed drinking water and irrigation for many people in the region, including rural farms, ranches, and local communities.
“It is vital that we have the most accessible scientific information, such as this report, to give a clear picture of Lake Powell water availability as we plan for the future,” Tanya Trujillo, Assistant Secretary for Water and Science at the U.S. Department of the Interior . , the message says. “The Colorado River system is facing multiple challenges, including the effects of a 22-year drought and the increasing impact of climate change.”