Damage to outlet tubes stirs worries
Water at Lake Powell could become stranded
ATLANTA — Plumbing problems at the dam holding back the second-largest reservoir in the U.S. are spurring concerns about future water delivery issues to Southwestern states supplied by the Colorado River.
Federal officials recently reported damage to four tubes known as “river outlet works” at Glen Canyon Dam on the Utah-arizona border. The dam is responsible for generating hydropower and releasing water stored in Lake Powell downstream to California, Arizona, Nevada and eventually Mexico.
The U.S. Bureau of Reclamation, which operates the major dams in the Colorado River system, is evaluating issues related to Glen Canyon Dam when Lake Powell reaches low levels. Those issues include problems with the four tubes such as sedimentation and cavitation — when tiny air bubbles develop while water passes through plumbing.
The Colorado River provides water to seven U.S. states, nearly 30 Native American tribes and two states in Mexico. Years of overuse by farms and cities and stubborn drought has meant that much less water flows today through the 1,450-mile river than in previous decades.
Lake Mead and Lake Powell serve as barometers of the Colorado River’s health. In recent years, they have fallen to historic lows then recovered somewhat thanks to above-average recent winter precipitation and water conservation.
The structural problems at Glen Canyon Dam could complicate how federal officials manage the river in years to come when hydrologists and others predict Lake Powell will fall below current levels.
Brenda Burman, general manager of the Central Arizona Project, a 336-mile canal system that delivers Colorado River water to Arizona’s cities, raised the issue at a meeting last month related to the river.
JB Hamby, chairman of the Colorado River Board of California, said the dam’s design leaves open the possibility that huge amounts of water could be stranded in Lake Powell under low elevations.
He said an engineering solution would be the best way forward because other options could involve additional water cuts to states.
Doug Maceachern, communications administrator at the Arizona Department of Water Resources, said his agency was working with Reclamation to see “what, if any, technical fixes might exist.”
If federal officials can’t repair the tubes, Maceachern said his agency expected Reclamation to not place the burden of more water cuts solely on Arizona, California and Nevada, which make up the river’s so-called Lower Basin. Colorado, New Mexico, Utah and Wyoming form its Upper Basin.