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Moffat Collection System Project

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Denver Water is investing millions of dollars in developing innovative ways to meet its most important responsibility — ensuring customers always have the quantity and quality of water they need. To do so, Denver Water has a diverse plan to meet those future needs: conserve, recycle and develop.

And it’s working. Since the early 1970s, the number of people we serve has increased by almost 50 percent while the amount of treated water they use has increased only 6 percent. Denver Water’s recycled water distribution system is freeing up enough drinking water to serve roughly 15,000 households; once it’s complete, the system will free up enough drinking water to serve almost 45,000 homes.

And Denver Water’s Moffat Collection System Project — which will enlarge Gross Reservoir — is one of the major elements of our supply plan. The project will help resolve three major supply challenges: a future water shortfall, the risk of running out of water in a future drought and a serious imbalance in Denver Water’s collection system.

The Moffat Collection System Project proposes to enlarge Gross Dam’s height from its current 340 feet to approximately 471 feet to increase the reservoir’s capacity.

The Project

The Moffat Collection System Project will provide 18,000 acre-feet of annual supply by enlarging Gross Reservoir, an existing reservoir, rather than building a new one. The current dam height will increase by approximately 130 feet, nearly tripling the reservoir’s capacity. The project will increase the reservoir’s current storage capacity of 41,811 acre-feet to approximately 119,000 acre-feet, which includes a 5,000 acre-foot environmental pool. The environmental pool will be used to enhance streamflows in South Boulder Creek below Gross Reservoir.

Through enhancements that are contingent on the Moffat Project, the project will provide many benefits to the West Slope, making the West Slope better with the Moffat Project than without it. In order to gain the support necessary to proceed with the Moffat Project, Denver Water took an unprecedented approach of negotiating with more than 40 entities in western Colorado, from the Continental Divide to the state line, including Grand and Summit counties.

Denver Water recognizes the interdependencies between the East and West slopes, and that the old way of water development in Colorado will be divisive, and destructive to the environment and economy. As a result, Denver Water and the West Slope agreed on a simple yet powerful goal: To make the West Slope better with the Moffat Project than without it.

The Colorado River Cooperative Agreement, the result of those negotiations, provides for an array of enhancements over and above the mitigation of impacts that will be required under state and federal environmental permitting processes for the Moffat Project. The agreement represents a more responsible way of water development in Colorado. It has been hailed as a model for the future in statewide inter-basin water discussions.


Denver Water is interested in your comments and will answer what questions it can at this time. Send questions to publicinformation@denverwater.org.

Gross Reservoir neighbors

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