geo.wikisort.org - Reservoir

Gross Reservoir, located in Boulder County, Colorado, is owned and operated by Denver Water. Completed in 1954, the reservoir has a surface area of 440 acres, and the spillway sits at 7,225 feet elevation.[1]

Gross Reservoir
The reservoir in 2014.
Gross Reservoir Show map of Colorado Gross Reservoir Show map of the United States
Location	Boulder County, Colorado
Coordinates	39°56′31″N 105°22′22″W
Type	reservoir
Etymology	Named for Denver Water former Chief Engineer Dwight D. Gross.[1]
Primary outflows	South Boulder Creek
Basin countries	United States
Managing agency	Denver Water
Water volume	41,811 acre⋅ft (51,573,000 m3)
Surface elevation	2,222 m (7,290 ft)[2]

The reservoir receives water from the western side of the Continental Divide through the Moffat Tunnel. South Boulder Creek flows out of the 340 foot-high dam.

Recreation

The reservoir provides opportunities for fishing (including ice fishing), hiking, canoeing, kayaking, and some camping. No water-contact sports such as swimming or wading are allowed. Only non-motorized boats are permitted — the type that can be attached to the top of a car.[1]

Expansion project

The proposed expansion of Gross Reservoir would allow Denver Water to store 77,000 additional acre feet of water, drawn mostly from the Fraser and Williams Fork Rivers.[3] Construction on the project, expected to be complete around 2025, will raise the level of the dam by 131 feet (40 meters), resulting in an additional 77,000 acre-feet (95,000,000 cubic meters) of water storage capacity in the reservoir and making it the tallest dam in Colorado.[4]

Denver Water applied to the U.S. Army Corps of Engineers for a permit under section 404 of the Clean Water Act, required to construct the expansion, and that permit was granted in 2017.[5] In response, several environmental groups sued USACE on grounds that the agency's deliberations about granting the permit violated the Clean Water Act, Endangered Species Act, and National Environmental Policy Act.[6] In July 2020 the Federal Energy Regulatory Commission granted a required modification to the Federal Power Act license granted to Colorado Water for Gross Dam before it was built.[7]

A contract for design services was awarded to Stantec, an engineering consulting firm, in 2017.

Boulder County announced in spring 2019 that it would require Denver Water to obtain a land use permit under Colorado law before commencing the expansion project.[8] Denver Water submitted its application for that permit in September 2020.[9]

See also

• List of largest reservoirs of Colorado
• List of reservoirs in Colorado

References

External links

• Expansion Project official website
• Anti-Expansion Project official website

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