Plumbing problem at Glen Canyon Dam brings new threat to Colorado River system

Plumbing problems at the dam holding back the second-largest reservoir in the U.S. are raising concerns about future water supply problems for southwestern states served by the Colorado River



April 16, 2024, 8:17 p.m. ET

4 minutes read

ATLANTA (AP) — Plumbing problems at the dam holding back the nation's second-largest reservoir are raising concerns about future water supply problems for Southwest states served by the Colorado River.

The U.S. Bureau of Reclamation, which operates the largest dams in the Colorado River system, is currently reviewing issues related to Glen Canyon Dam when Lake Powell reaches low levels. These problems include problems with the four pipes such as sedimentation and cavitation – when tiny air bubbles form as water flows through the pipes. Cavitation can cause metal cracks and other mechanical damage.

The Colorado River supplies water to seven U.S. states, nearly 30 Native American tribes, and two states in Mexico. Years of overuse by farms and cities, as well as persistent drought worsened by climate change, have resulted in much less water flowing through the 1,450-mile (about 2,336-kilometer) river today than in past decades.

Lake Mead and Lake Powell, which store water and are used for recreation and power generation, serve as a barometer for the health of the Colorado River. In recent years, they fell to historic lows and then recovered somewhat thanks to above-average winter precipitation and water conservation.

The structural problems at Glen Canyon Dam, first reported by the Arizona Daily Star, could complicate how federal officials manage the river in the coming years as hydrologists and others predict Lake Powell will fall below current levels. The damaged pipes lie beneath much larger pipes, called pressure pipes, that normally carry the reservoir's water. The smaller tubes that make up the “river outlet works” allow water to be released to lower reservoir levels.

Lake Powell is currently at about 32% capacity.

Brenda Burman, general manager of the Central Arizona Project, a 336-mile (541-kilometer) canal system that supplies Arizona cities with water from the Colorado River, raised the issue at a river-related meeting last month.

“We have received some difficult news from the Bureau of Reclamation,” Burman said, adding that CAP will work with Reclamation in the coming months to investigate the issues.

JB Hamby, chairman of the Colorado River Board of California, said the dam's design leaves open the possibility that large amounts of water could become stranded at low elevations in Lake Powell.

He said a technical solution is the best path forward because other options could involve additional water cuts for states.

Doug MacEachern, communications administrator for the Arizona Department of Water Resources, said his agency is working with Reclamation to figure out “what, if any, technical solutions there might be.”

If federal officials can't repair the pipes, MacEachern said his agency expects reclamation will not shift the burden of further water cuts solely to Arizona, California and Nevada, which make up the river's so-called subbasin. Colorado, New Mexico, Utah and Wyoming make up the upper basin.

Separately, states and tribes that rely on the Colorado River are working on a long-term agreement to share the dwindling resource after current water-sharing rules and guidelines expire in 2026.

Environmental groups have warned for years that water levels at Lake Powell could reach a point where Glen Canyon Dam can no longer be used for hydroelectric power or can no longer release water downstream.

“What is at risk?” said Kyle Roerink, executive director of the environmental organization Great Basin Water Network. “The water supply for 25 million people and large agricultural producers.”


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