Upper Yampa Water Conservancy District managers plan to enlarge Stagecoach Reservoir by raising the height of the hydroelectric dam 5 or 6 feet, district manager John Fetcher said. If permits and engineering go according to plan, construction should be complete in fall 2005, he said.
"Construction-wise, it's not a big deal," Fetcher said.
The plan is to raise the spillway with an extended concrete structure, similar to what the district did at Yamcolo Reservoir a couple of years ago.
The most time-consuming part of this process is the planning.
Upper Yampa Water Conservancy District officials started the permit application process with the Army Corps of Engineers a couple of months ago, Fetcher said. Small, orange flags waving around the lake's shore are the beginning of that process. The flags are marking "fringe wetlands" that were created as a result of underground water seeping in when the reservoir was filled, Fetcher said.
Ken Jacobson, a biologist with the Army Corps of Engineers, will be visiting the site Wednesday to review the wetland boundaries that have been marked. This process of verifying the extent of the existing wetlands is a precursor to the district's full application, Jacobson said.
If the reservoir expands, the water conservancy district will have to mitigate any flooded wetlands within the watershed, Jacobson said. He added that it is too early to estimate what the effects of an expanded reservoir might be.
Two-hundred-sixty acres of wetlands were inundated by the initial flooding of Stagecoach Reservoir, Fetcher said. Even though the district got an unusual 160-acre credit for the high-quality 80-acre wetland refuge at the lake's intake in 1987, these days, the mitigation ratio typically is the opposite, he said. That means the district likely will have to create 2 new acres of wetlands for every acre that is lost to expansion of the reservoir.
As far as recreation is concerned, Stagecoach State Park managers think expanding the reservoir is a good idea. The state park leases the surface water and surrounding land from the Upper Yampa Water Conservancy District.
"It's a positive thing that they're going to hold back more water and increase the surface area of the lake," park manager Mike Taylor said. "Overall, I look on it as a positive step."
Though the potential new shape of the lake is unknown, Taylor said he thinks the expansion will improve some of the recreational facilities.
"It's going to put some of the campsites closer to the water's edge, which is more attractive to campers," Taylor said.
But an expansion also will create infrastructure changes. The trail that surrounds the lake will have to be realigned, parking lots may have to be shored up for stabilization and some of the park's septic vaults may need to be moved if the water table gets too close. Such expenses will be the responsibility of the water conservancy district, Taylor said.
Increasing the reservoir's level is not expected to affect the fishery or recreational infrastructure, Fetcher said. It will, however, flood the beach, he said.
Affecting the swimming beach near the park headquarters is a big disappointment, Fetcher said.
"That swim beach is my pearl. It's such a lovely beach," Fetcher said.
"I would love to see the beach stay where it is. Everybody likes it a lot," he said.
Instead, the beach will be moved -- sand and all -- farther back into its protected cove once the lake's level increases, Fetcher said.
If the proposed dam extension is built and Stagecoach Reservoir fills, it will add 4,000 acre feet of water storage to the lake. That's enough water to flood a football field 4,000 feet deep -- or sufficient water to supply an estimated 8,000 families per year.
A larger reservoir, if full, also would allow the dam to create more electricity by increasing the pressure on the turbine.
Among the many bureaucratic steps along the way to gaining dam expansion approval, the water conservancy district also will have to amend its license with the Federal Electric Regulatory Commission.
"But how often is it going to be full?" Fetcher mused, acknowledging that Routt County is in the midst of a drought.
Stagecoach Reservoir likely will not fill this year. The reservoir was about 3 feet, 8 inches below full Wednesday.
A public meeting with the Army Corps of Engineers is expected to take place in August, where public comments about the Stagecoach Reservoir project will be taken. Fetcher said he hopes to hold the meeting in Oak Creek so it is convenient for the Stagecoach community.
If the dam expansion permit is approved, construction would begin after Labor Day 2005, Fetcher said. The lake level would have to be lowered about 5 or 6 feet during construction.
"It is hard for me to envision where there might be any opposition to this," Fetcher said, speaking from decades of water project experience.