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

Getting a (big) jump on a healthy environment

May 21, 2021 - TAP - Denver Water completing required stream and habitat improvements years ahead of final go-ahead for Gross Reservoir expansion. “Our No. 1 objective is to do right by our partners, by our customers and by the environment,” said Jeff Martin, project...

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2020 Year-End Report

Last year was unique and required a lot of adaptation but we are proud of what we were able to progress throughout 2020. The 2020 Year-End Report can be viewed by clicking the image below.

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