April 21, 2011 - Denver Water, in coordination with the Colorado Division of Wildlife and the Office of the State Engineer, will lower Antero Reservoir by two feet beginning the first week of May. The gradual drawdown will take four to five weeks. Denver Water will keep the popular reservoir open to recreation, and the Colorado Division of Wildlife will continue to manage the fishery.
The drawdown is a safety precaution to reduce water pressure and seepage within the dam to ensure it doesn’t pose a safety risk to area visitors and residents. Antero Dam, built in 1909, has experienced excessive seepage since it was built and has been operating under reservoir storage restrictions by the state since the early 1900s to ensure public safety.
“The dam has exhibited seepage for a prolonged period,” said Mike Miller, Denver Water dam safety engineer. “Our accrued measurement data from within the dam indicate we need to conduct further studies to determine the extent of damage. Lowering the reservoir elevation as a safety precaution will reduce seepage impacts.”
Further engineering evaluations of the dam will determine the long-term plan for the facility. The duration of the study will depend on what Denver Water learns from the initial information.
“Denver Water and the Colorado Division of Wildlife are working cooperatively to examine all of the possibilities to lessen the potential impacts to the fishery from the drawdown,” said Jeff Spohn, northeast region aquatic biologist. “Once Denver Water finishes its study, we will have a better understanding of future fish management at Antero.”
“We recognize the importance of Antero Reservoir to Park County’s economy and as a prime fishery for anglers, but need to drawdown the reservoir for public safety,” said Miller. “We will keep the county, DOW and reservoir users informed as the study progresses.”
Antero Dam was completed in 1909 by Canfield and Shields of Greeley, and its purchase was finalized by Denver Water in 1924. The reservoir was named Antero, derived from the Spanish word “first,” because it was the first reservoir on the South Platte, nearest to the river’s headwaters.