Massive study evaluates and discloses impacts of new Fraser River diversions, expanded Gross Reservoir
By Bob Berwyn
FRISCO — Not developing new water diversions from the Colorado River Basin to the Front Range would increase the chances of a major Denver Water system failure, the U.S. Army Corps of Engineers concluded in its final environmental impact study for the Moffat Tunnel Collection System expansion.
The federal agency, charged with evaluating and disclosing impacts of the proposal, claims that Denver Water customers could experience periodic raw water and treated water shortages in dry years, with Arvada, Westminster and the North Table Mountain Water and Sanitation District especially vulnerable to raw water shortages.
“Severe and more frequent mandatory watering restrictions, including surcharges, may result in a reduced quality of life and place financial burdens on customers. Though still infrequent, mandatory restrictions would reduce production, employment, and other business activity in the Denver Metropolitan area,” The Corps wrote in the executive summary of the massive study.
At issue is Denver Water’s plan to increase diversions primarily from the Fraser River, though the proposal would have a ripple effect on other rivers, streams and reservoirs west of the Continental Divide. Denver Water says the new diversions, which would be stored in an enlarged Gross Reservoir, will help balance the northern and southern branch of its water distribution network.
While Denver Water has reached agreement with some environmental stakeholders on a conceptual plan to mitigate impacts, other groups are still strongly opposed to the plan, claiming that Denver Water could achieve its objectives without new diversions with smarter water use policies, especially better conservation.
In a press release, several groups expressed continued opposition to the plan, charging that enlargement of Gross Reservoir would “flood unique natural areas of rural Boulder County in a greatly enlarged Gross Dam and Reservoir before being piped to the sprawling lawns and suburbs in Denver Water’s service area.”
Here’s how some conservation groups reacted to release of the final environmental impact statement on the $360-million, 18,000-acre-foot project
“The Moffat expansion is far from a done deal,” said senior Earthjustice attorney McCrystie Adams. “This project should not be approved unless the long-term health of the river is assured and our nation’s environmental standards are met. We and our partners are committed to keeping the Colorado River flowing,” Adams said.
“The Colorado River is endangered from the source to the sea. Its flows are depleted or drained, its habitat is suffering, its endangered fish are on the brink of survival … this river has already given more than it can,” said Gary Wockner, coordinator for the Save The Colorado River Campaign. “The extremely controversial Moffat Project will face intense scrutiny and analysis in the coming months and years.”
Denver Water says a conceptual mitigation agreement will actually result in environmental improvements in the Fraser River drainage, with intensive monitoring and adaptive management aimed at ensuring conservation of aquatic resources.