Gross Reservoir Expansion Project

Once fully approved, the Gross Reservoir Expansion Project will undergo approximately three years of design followed by four years of construction.

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 begning in 2003 to analyze environmental effects of enlarging the existing Gross Reservoir (near Boulder, Colo.) to supply 18,000 acre-feet per year new firm yield of water to its Moffat Collection System. On July 6th 2017, the Army Corp of Engineers approved Denver Water’s request to raise Gross Dam in Boulder County.

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Water projects take patience, stewardship

Water projects take patience, stewardship

Journal Advocate – June 29, 2018 – "As a result of going above and beyond, the Gross Reservoir expansion includes an "environmental pool" of 5,000 acre feet of water to benefit 17 miles of aquatic habitat in South Boulder Creek..." Read more...

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