Project ensures reliable water deliveries and infrastructure resilience for future generations
The outlets consist of four large steel pipes that move water from Lake Powell directly into the Colorado River, bypassing the hydropower generating units. The original coal-tar coating, more than 60 years old, was removed and replaced with an epoxy primer and a durable polysiloxane topcoat. The recoating effort is part of the regular, long-term maintenance of the dam.
PAGE, Ariz. – The Bureau of Reclamation completed the recoating of the river outlet works at Glen Canyon Dam and Powerplant—more than two months ahead of schedule and on budget. The work was supported by an $8.9 million investment from the Infrastructure Investment and Jobs Act and is part of Reclamation’s continued effort to modernize critical water infrastructure across the West.
“This is a smart, forward-looking infrastructure investment that will improve Colorado River water operations,” said Reclamation Acting Commissioner David Palumbo. “Finishing this project ahead of schedule and on budget speaks to the quality of planning, partnership, and execution by our team and contractors.”
The outlets—also referred to as bypass tubes—consist of four large steel pipes that move water from Lake Powell directly into the Colorado River, bypassing the hydropower generating units. Their recoating is part of the regular, long-term maintenance of the dam. The original coal-tar coating, more than 60 years old, was removed and replaced with an epoxy primer and a durable polysiloxane topcoat. The new coating was applied using a robotic sprayer and is expected to significantly extend the service life of the outlets. The epoxy and polysiloxane coating system has been successfully applied in other major infrastructure projects, including Fontana Dam (North Carolina), Pineview Dam (Utah), and Grand Coulee Dam (Washington).
“This project reinforces our commitment to maintaining the safety and integrity of Glen Canyon Dam while ensuring we can reliably deliver water to millions of people who depend on the Colorado River,” said Upper Colorado Basin Regional Director Wayne Pullan. “By investing in this critical maintenance, we are building resilience for the future.”
Although the outlets have historically been used sparingly—since most water is released through the dam’s hydropower units—they provide releases for downstream commitments when the hydropower units are not in operation and, more recently, for experimental releases. For example, during last year’s cool mix flows, Reclamation released water through both the hydropower units and the outlet works to send colder water downstream and disrupt nonnative fish spawning below the dam.
The recoating project also addressed minor cavitation damage discovered following the April 2023 high-flow experiment when the outlets were operated at low reservoir levels. While the new coating will not prevent future cavitation, Reclamation is managing this risk through updated operational protocols and ongoing analysis.
This recoating is a priority maintenance effort and is a key component of Reclamation’s work to sustain the reliability and safety of Glen Canyon Dam, which impounds Lake Powell—the second-largest manmade reservoir in the United States.
