The US Bureau of Reclamation has begun replacing all four original valves at Blue Mesa Dam for the first time since the facility was completed in 1966. The $32m federally funded project is expected to extend the operational life and reliability of one of Colorado’s primary water storage and hydropower facilities.
Blue Mesa Dam, the largest structure in the Aspinall Unit on the Gunnison River, stands 390ft tall and forms Blue Mesa Reservoir, which has a storage capacity of nearly 941,000 acre-feet. Along with Morrow Point and Crystal dams, the Aspinall Unit provides water storage, flood control, and hydropower generation. The Blue Mesa power plant has an installed capacity of 86MW.
The project involves replacing two ring follower gate valves and two butterfly valves that regulate water movement through the dam.
Work began in January with removal of the first ring follower gate. The assembly measures approximately 18ft long by 7ft wide and weighs about 14 tons. Its hydraulic hoist system weighs an additional 12 tons. Prior to removal, crews installed a blind flange.
The removed gate has been transported to California for refurbishment and is scheduled to return for reinstallation in August. Following completion of that phase and a reduction in irrigation demand later this fall, the blind flange will be removed and normal operations restored. Crews will then proceed with replacement of the second ring follower gate and subsequently the two butterfly valves.
“This work is complex,” said Blue Mesa Plant Supervisor Eric Langely. “We must maintain minimum river flows downstream, avoid disruptions at Morrow Point and Crystal dams, and manage drought-related constraints – all while working inside a dam built nearly 60 years ago.”
The USBR is managing the multi-year effort with in-house engineers, plant operators, and technical specialists. Officials state the upgrades are intended to support continued safe operations and hydropower production at Blue Mesa Dam for decades.
