Gross Reservoir Expansion Project

The Gross Reservoir Expansion Project will undergo approximately three years of design, finishing in 2021, followed by the start of construction in 2022.

Primary dam construction is anticipated to last two construction seasons, a total of 18 months. During this time, work at the construction site will often be 24 hours a day, 7 days a week. The project involves the raising of the existing 340 foot tall Gross Dam by an additional 131 feet to create the new larger reservoir and additional storage. Based on the concept design, once complete, Gross Reservoir will be the tallest dam in Colorado and will contain about 1.5 million cubic yards of concrete, about half the volume of Hoover Dam.

 

Technically Speaking

 

The U.S. Army Corps of Engineers, Omaha District Regulatory Branch, prepared an Environmental Impact Statement beginning in 2003 to analyze environmental effects of enlarging the existing Gross Reservoir (near Boulder, Colorado) to supply 18,000 acre-feet per year new firm yield of water to its Moffat Collection System. On July 6th 2017, the U.S. Army Corps of Engineers approved Denver Water’s request to raise Gross Dam in Boulder County.

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Latest News / Blog

Breathtaking work nearly 300 feet underwater

August 23, 2021 - TAP - Major project replacing large debris grate at Gross Dam requires experts in the harrowing field of saturation diving. Raitt stresses the project is wholly unrelated to the planned expansion of Gross Reservoir. It would be happening regardless...

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All the ways we save (It’s not just shorter showers!)

August 6, 2021 - TAP There are a few things many customers might know about Denver Water’s efforts to use water efficiently. There was that fun and flashy and very effective 10-year “Use Only What You Need” campaign that cut per person water use by 22%. Denver Water...

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