Wednesday, October 24, 2007
State officials are preparing to spend more than $400,000 on repairs to the "high hazard" dam at Pearl Lake State Park next summer.
The earthen dam at Pearl Lake - technically known as Lester Creek Reservoir - was constructed in 1963. It was built on the Routt National Forest and is managed cooperatively by Colorado State Parks and the Colorado Division of Wildlife.
It is among 332 dams in Colorado that carry the "high hazard" designation. However, that does not imply that there is imminent danger of a dam failure at Pearl Lake, Mike Havens said.
Havens is the dam repair project manager for Colorado State Parks.
High hazard dams must undergo annual inspection by engineers with the Colorado Division of Water Resources, because failure of the dam could mean the loss of human life and significant property damage.
"Lester Creek Reservoir is a safe dam," Havens said. "The state inspects it annually to look for worrisome signs. If a dam gets into trouble, it usually doesn't happen very fast."
Routt County Emergency Management Director Chuck Vale said he is aware of the steps being taken at Lester Creek and Pearl Lake.
"I believe the state is on the right road to making repairs," Vale said. "I support 'hurry up and get it done' so we don't have a catastrophe at the dam."
Lester Creek drains melting snow from Farwell Mountain into Pearl Lake. The creek exits the bottom of the dam and flows just more than a mile before merging with Willow Creek. That body of water flows another two miles before reaching its confluence with the Elk River above Glen Eden Resort and Clark.
Havens said the work that will take place at the dam next July and August includes rehabilitating the "outlet works," including replacement of the existing sluice gate, and upgrading the toe drain system.
The toe drain system is used to channel moisture away from the base of the dam before it can destabilize the structure. Presently, the toe drains aren't working as well as engineers would like them to, he said.
The replacement of the sluice gate has to do with loss of water storage, Havens said. He explained that the sliding metal "face plate" on the grate at the bottom of the dam slides into a matching metal frame. The metal-to-metal contact provides a seal.
Repairs would be made by divers when the reservoir is full, and is a challenging operation.
The invitation to bid on the project reads: "This task has the potential to initiate dam failure, and will require significant effort to maintain dam safety."
Those words were chosen to alert prospective contractors to the challenges inherent in the project, Havens said.
"There are two things I never want to do," Havens said. "One is to tell my boss we lost the dam. The other is to have a diver injured in any way. It's not to say I fear that we're doing something that is risky, because we're not. .... I just want to make sure we get qualified operators."
There are good people out there with experience working on dams."