Water levels plunge at Lake Powell. Is 'dead pool' looming?

USA Today

2 days ago

Sinking water levels at the giant reservoir on the Utah-Arizona border have led to renewed concerns about power generation and water supply.
Water levels at Lake Powell, the giant reservoir on the Utah-Arizona border, have dropped to their lowest point in three years, prompting boat ramp closures and raising fears about downstream water supplies and hydroelectric power generation that could affect millions of people across the West.
The U.S. National Park Service announced that one of the primary boat launches within the Glen Canyon National Recreation Area in Utah – the Wahweap Main Launch Ramp – will be closed starting Aug 18. And the Park Service is relocating the Rainbow Bridge floating dock into deeper water.
Of greater concern in the long term is how dropping water levels will impact both power generation and water supply: There's a chance that Lake Powell's water level could fall to an elevation that would force the stoppage of power generation at the Glen Canyon Dam, which would affect electricity supply to millions of people in many states.
Additionally, another concern is the chance that Lake Powell could reach so-called "dead pool" status by December 2026. That is the level at which a dam can no longer release water downstream.
According to the U.S. Bureau of Reclamation and the U.S. Department of the Interior, if dead pool is reached at Lake Powell, residents of seven western states – Wyoming, Utah, Colorado, New Mexico, Arizona, Nevada and California – could possibly see power blackouts and water shortages.
A long-term water crisis
The Colorado River and Lakes Mead and Powell have been suffering because of a multi-decade drought in the West intensified by climate change, rising demand and overuse. The river also serves Mexico and more than two dozen Native American tribes, produces hydropower, and supplies water to farms that grow most of the nation's winter vegetables.
A June report from environmental firm AEM showed that Mead and Powell, crucial reservoirs that provide drinking water for 40 million Americans, have "reached alarmingly low levels, holding just one-third of their usual capacity. This shortage poses significant challenges to agriculture, urban water supplies, and industries reliant on consistent water availability."
That's up from a low point in 2022, when the reservoirs were 25% full but still far from historic highs of the early 2000s, when they were 95% full.
What is the 'dead pool'?
At Lake Powell, "dead pool" is the water level at which the lake can no longer release water downstream through Glen Canyon Dam. This happens when the water level falls below the lowest outlets, trapping water within the bottom of the reservoir.
It's basically the point where the dam no longer functions as a conduit for the Colorado River's flow.
Megadrought blamed on human activities
Lake Powell's water woes are playing out against the backdrop of a "megadrought" that's plagued the West for the past two decades.
According to a new study released in the journal Nature, greenhouse gas and aerosol emissions from human activity have been driving the prolonged drought in the western United States through a complicated connection with the Pacific Ocean.
"For more than two decades, an extreme dry spell has drained the Colorado River, devastated local farms, and intensified wildfires across the American Southwest," according to a statement from Colorado University-Boulder.
'Our results show that the drought and ocean patterns we're seeing today are not just natural fluctuations – they're largely driven by human activity,' said Jeremy Klavans, postdoctoral researcher in CU Boulder's Department of Atmospheric and Oceanic Sciences and lead author of the study.