• US Bureau of Reclamation warns against heavy reliance on Glen Canyon Dam’s outlet works.
• Extended use of outlet works at low lake levels could cause significant damage.
• Maintenance planned, but long-term water conservation emphasized to protect dam infrastructure.

April 12, 2024 — The US Bureau of Reclamation has released a memo detailing potential risks to Glen Canyon Dam’s water release infrastructure if Lake Powell’s water levels fall below the point where power generation is viable. The dam relies on underwater outlet works (steel tubes) to release water in such scenarios. The memo highlights the significant risk of damage if these tubes are used for extended periods.

Reclamation’s technical memo emphasizes that if any part of the outlet works system fails, water releases would be severely limited or impossible until repairs are made. To mitigate these risks, Reclamation plans to make maintenance and operational improvements to the dam. This includes potential repairs to the outlet works starting in late 2024 or early 2025.

Bureau officials stressed that even with these improvements, water releases through the outlet works may need to be reduced by up to 17% if the lake level drops too low. This is due to the risk of cavitation – the formation of damaging bubbles within flowing water.

Glen Canyon Dam.

Glen Canyon Dam was constructed to harness the power of the Colorado River in order to provide for the water and power needs of millions of people in the West.  It is the second highest concrete-arch dam in the United States, second only to Hoover Dam. Hydroelectric power produced by the Glen Canyon Dam’s eight generators has a total capacity of 1,320 megawatts. Glen Canyon Power Plant produces around five billion kilowatt-hours of hydroelectric power annually which is distributed by the Western Area Power Administration to Wyoming, Utah, Colorado, New Mexico, Arizona, Nevada, and Nebraska.

The memo and accompanying statements from Bureau of Reclamation officials underscore the urgent need for water conservation across the Colorado River Basin. Keeping Lake Powell’s elevation above the minimum level for power generation is crucial to protect Glen Canyon Dam’s critical water release infrastructure.

Image:

The Glen Canyon Dam on the Colorado River forms Lake Powell in northern Arizona, May 1998, by Nikater.  Released into the public domain via Wikimedia Commons.