Water levels in the nation’s second-largest reservoir reached a new record low on Tuesday, February 14, 2023. The water level was reported at 3,522.16 feet above sea level, or about 22% of the reservoir’s capacity.
Despite strong snow and heavy rains this winter, water demand by states that rely on the Colorado River threatens the reliability of clean water supply for an estimated population of 40 million people and the ability to generate hydroelectricity for 5 million people.
At 3,490 feet, the water level that the U.S. Bureau of Reclamation refers to as “minimum power pool,” the dam may be unable to generate hydropower. Water would fall below normal intakes. In turn, air pockets can enter turbines and damage the expensive assets.
Water could flow through the dam via narrow and rarely-used “river outlet works,” originally designed to pass water in high flow years. The backup pipes “aren’t wide enough to carry the legally required amount of water from one side to the other.”
At 3,370 feet, Lake Powell reaches “dead pool” and water can no longer pass through the dam via gravity.
As Reclamation has been cutting back on dam releases under an existing drought response agreement, the water levels are anticipated to rise about 10 feet between December, 2022 and April, 2023.
In May, snow meltoff is expected to help rise Lake Powell.
Six states have signed an agreement to conserve 1.5 million acre-feet of water for each of the next two years. The proposed total is less than the 2 to 4 million acre-feet Reclamation said it would need to avoid more problems at Glen Canyon Dam.
(The 1.5 million acre-feet volume of water is roughly the amount lost to evaporation in Lake Mead, the nation’s largest reservoir, and to leaky water infrastructure in the river’s Lower Basin states of California, Arizona and Nevada.)