Gross Reservoir Expansion Project

As a federally permitted project, the purpose, need and environmental impacts of the project have been vetted through almost a decade of research. The U.S. Army Corps of Engineers released the Final Environmental Impact Statement (FEIS) in 2014 that details project mitigation measures and addresses public comment received after publication of the Draft Environmental Impact Statement. Like many water supply projects, there are a number of permits at the federal, state and local level that are needed before construction can begin:
  • 401 Certification
    • Also a component of the Clean Water Act of 1972, 401 Certification is a process handled at the state level. In the case of the Gross Reservoir Expansion Project, the Colorado Department of Public Health and Environment (CDPHE) is responsible for evaluating the impacts of and ensuring water quality associated with this project.
    • Secured: June 2016

    Record of Decision (ROD) and 404 Permit

    • A major responsibility of the Army Corps of Engineers (ACE) is administering the permitting program under Section 404 of the Federal Water Pollution Control Act of 1972, also known as the Clean Water Act. Permit review and authorization is a thoughtful and lengthy process that encourages avoidance of impacts, followed by minimizing impacts and, finally, requiring mitigation for unavoidable impacts to the aquatic environment.
    • 404 Permit
    • Secured: July 2017.
  • Federal Energy Regulatory Commission (FERC) License Amendment
    • The Gross Reservoir Dam includes a 7.6 mW hydropower unit, which is licensed for operation by FERC. Under the Federal Power Act, FERC has exclusive authority to license nonfederal hydropower projects. The amendment of license process requires that FERC address both the economics and engineering issues and the potential environmental and socioeconomic effects of project development and operation.
    • Denver Water expects to receive the License Amendment by the end of 2018.

Environmental Commitments

Provide $2 million towards aquatic habitat improvements on the Upper Colorado River.

Environmental Commitments

Provide $1 million to the Upper Colorado River Wild and Scenic Management group to fund flow-related projects to protect the outstanding and remarkable values within segments of the Upper Colorado River.

Environmental Commitments

Provide $6 million to Grand County to use towards environmental projects, and continue to participate in the “Learning By Doing” collaborative effort, which has already resulted in tangible positive environmental impacts on the West Slope.

Environmental Commitments

Construct and maintain sediment pond on Berthoud Pass to keep the Fraser River bottom clean. Check out, “Good for drivers, bad for the Fraser River.”

Environmental Commitments

Restore a portion of Fraser Flats in Grand County. Check out, “Keep it cool: Good for the Fraser River and its trout.”

Environmental Commitments

Release water into Ranch Creek in response to high temperatures found through water temperature monitoring. Check out, “Searching for solutions to help trout keep their cool.”

Environmental Commitments

Monitor stream temperatures and water quality in Gross Reservoir, South Boulder Creek and the Fraser River Basin.

Environmental Commitments

Provide funding towards Colorado Parks and Wildlife’s cutthroat trout habitat projects to protect and restore native trout populations.

Environmental Commitments

Through a cooperative process, replace culverts on Fraser River, Cabin Creek and St. Louis Creek with Aquatic Organism Passage culverts that will enable free passage of fish and other aquatic organisms.

Environmental Commitments

Provide flushing flows in the Williams Fork and Fraser River basins.

Environmental Commitments

Provide more than 1,000 acre-feet of water in Grand County for environmental purposes.

Environmental Commitments

Complete a stream restoration project on South Boulder Creek in partnership with the City of Boulder.

Environmental Commitments

Create an environmental pool in Gross Reservoir that will be managed by the cities of Boulder and Lafayette to provide flows into South Boulder Creek during periods of low or no flows.

Environmental Commitments

Allow Grand County to store up to 2,500 AF of water in Williams Fork Reservoir for environmental purposes.

Environmental Commitments

Complete a stream restoration project on the Williams Fork River.

Environmental Commitments

Begin stream bank monitoring on the North Fork of the South Platte River and South Boulder Creek to identify erosion and/or unstable banks, and make repairs, as needed.

Environmental Commitments

Construct a fish ladder on Cabin Creek in Grand County.

Environmental Commitments

Convey approximately 540 acres of land near the Moffat Tunnel to the U.S. Forest Service for permanent protection and management as part of the National Forest System.

Environmental Commitments

Protect raptor species, fight invasive species, relocate rare plant species and responsibly remove trees and brush in the reservoir’s expanded footprint.

Environmental Commitments

Continue to participate in the U.S. Fish and Wildlife Service’s Upper Colorado River Recovery Program and the Platte River Recovery Implementation Program, both designed to protect endangered species.

Latest News / Blog

New technologies under review

The trees removed from the expanded reservoir may have a new life as “biochar,” improving soil for plants. Denver Water TAP - Expanding a reservoir has a lot of challenges, among them dealing with the trees and bushes that must be removed. Leaving this biomass in...

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Successful 2018 yurt season

With the sun drifting ever lower in the sky and the brilliant colors of fall a pleasant memory, the 2018 season for the Gross Reservoir Expansion’s Public Information Yurt has come to a successful finish. It was a great year marked by constructive two-way...

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