Renewable Revolution

August 17, 2021

A "bathtub ring" is visible at sunset in July during low water levels at the Lake Mead reservoir due to the Western drought. Photo: Patrick T. Fallon/AFP via Getty images


Federal officials, for the first time ever, declared a water shortage from the Colorado River on Monday — yet another bleak indicator of the magnitude of the drought across the West made worse by climate change. “It’s a historic moment where drought and climate change are at our door,” Chuck Cullom of the Central Arizona Project told the AP.

From left; Satellite images of Boulder Harbor Launch Ramp at Lake Mead in Boulder City, Nevada, on May 18, 2020, and on July 17 this year . Photo: Satellite image ©2021 Maxar Technologies

The "Tier 1" cuts were triggered by projections that Lake Mead — the largest reservoir on the Colorado River, created by the Hoover Dam — will be nearly 10 feet below the Tier 1 cutoff point on January 1, 2022. It was just three feet above that level, about 35% of its total capacity, on Monday.

“It’s as if a switch got flipped in 2000, and we now have a completely different river than we had in the 20th century,” Brad Udall, a senior water and research scientist at Colorado State University, told the Washington Post.

Under the complex system established 99 years ago, Tier 1 cuts, which take effect next year, will hit Arizona hardest, losing about 8% of its total water use.

Nevada and the country of Mexico will also see cuts, but California, because of its water rights seniority, will not see immediate cuts. (Washington Post $, AP, explainer, Colorado Public Radio, Salt Lake Tribune, New York Times $, Politico, Wall Street Journal $, Axios, CNN, NBC, Bloomberg $, E&E News, ABC; Climate Signals background: Drought)