Northern Colorado Gazette

By Mike Bauman

(Dow Insider Newsletter)

A Denver Water proposal to increase the amount of water being diverted to the Front Range would impact five rivers on both sides of the Continental Divide; according to a report presented to the Colorado Wildlife Commission Thursday.

Denver Water’s Moffat Firming project would increase the amount of water imported to the Front Range from the Fraser and Williams Fork drainages by 18,000-acre feet. This would provide a more reliable supply for the utility’s 1.3 million customers. Under state law, the Wildlife Commission will be asked to review and comment on a plan that Denver Water will develop to mitigate impacts of the project. The plan will then be forwarded to the Federal permitting agency.

Ken Kehmeier, senior aquatic biologist for the Platte River Basin, told commissioners that Denver Water’s Moffat Firming project would result in reduced stream flows and increased temperatures in the Williams Fork, Fraser and Upper Colorado River systems. According to Kehmeier, the lower flows would increase sedimentation in the affected reaches of these rivers and reduce  their ability to support aquatic insects and fish life.

On the East Slope, the additional diversions would send more water through the Moffat Tunnel, down South Boulder Creek and into an enlarged Gross Reservoir in Boulder County, Kehmeier said. The project would create a larger reservoir for recreation, however, longer periods of high flows in South Boulder Creek above Gross Reservoir would reduce its ability to support trout and other aquatic wildlife, he said.

First Assistant Attorney General, Tim Monahan, explained that state statutes allow the Wildlife Commission to address impacts of Denver Water’s new diversions so long as the mitigation is economically reasonable and maintains balance between development and reducing impacts to fish and wildlife resources. The commission can also address the cumulative impacts of this project and the Northern Colorado Water Conservancy District’s nearby Windy Gap Firming Project on the Upper Colorado River.

Kehmeier noted that Denver Water could opt to divert an additional 16,000 acre feet, mainly through Roberts Tunnel and South Platte basin through the southern part of its system without getting a new federal permit. That would likely cause significant impacts to Dillon Reservoir and the high-value trout fishery along the South Platte River, Kehmeier said, and it would not give the Wildlife Commission an opportunity to negotiate mitigation for the increased diversions.

Information provided courtesy Colorado Division of Wildlife Insider Program.

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