Gross Reservoir Expansion Project
Construction
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 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
Denver Water statement on seeking dismissal of its appeal of 1041 case
July 29, 2020 - A year ago, Denver Water submitted an application with Boulder County to begin the 1041 process related to the Gross Reservoir expansion. At the same time, we sought clarity in the courts on whether the expansion was subject to that process. Boulder...
Final federal approval secured for Gross Reservoir Expansion Project
DENVER — July 17, 2020 — Today, the Federal Energy Regulatory Commission ordered Denver Water to proceed with design and construction to expand Gross Reservoir in Boulder County. Seventeen years ago, Denver Water began the federal environmental permitting process that...