Gross Reservoir
Expansion Project

 

Gross Reservoir
Expansion Project

 

For information on blasting schedules, public access and roadwork activities, click the My Map image below.

Denver Water serves water to over 1.5 million people in metro Denver. Learn where Denver Water collects its water from in this video.

Environmental Commitments

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

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.
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.

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.”

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

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.”

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

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

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.

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

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

Complete a stream restoration project on South Boulder Creek.

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.

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

Complete a stream restoration project on the Williams Fork River.

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.

Construct a fish ladder on Cabin Creek in Grand County.

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.

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

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.

Online Office Hours

Now that construction has begun, we will continue to offer online one-on-one appointments with our project representatives who can answer your questions about the Gross Reservoir Expansion Project. We invite you to search for an available time and book an online meeting here.

We look forward to speaking with you!

News

Gross Reservoir recreation opening Saturday, July 2

Boulder, Colo. — July 1, 2022 — Recreation at Gross Reservoir will reopen Saturday, July 2, after a two-week closure to recover a vehicle from the reservoir following a fatal accident at the construction site for the dam expansion project on June 18. Operations for...

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Long-term recreation closure at Gross Reservoir

Boulder, Colo. — June 22, 2022 — Recreation at Gross Reservoir will remain closed for multiple weeks following the June 18 fatal accident at the Gross Reservoir Expansion Project where an engineer with six years of experience lost his life. This is essential as crews...

read more

Gross Reservoir recreation closed until further notice

Boulder, Colo. — June 18, 2022— Emergency responders are working on an accident that took place overnight at the Gross Reservoir Expansion Project site, in which a construction haul vehicle veered off the road into the reservoir. First responders and other agencies...

read more

News

Gross Reservoir recreation opening Saturday, July 2

Boulder, Colo. — July 1, 2022 — Recreation at Gross Reservoir will reopen Saturday, July 2, after a two-week closure to recover a vehicle from the reservoir following a fatal accident at the construction site for the dam expansion project on June 18. Operations for...

read more

Long-term recreation closure at Gross Reservoir

Boulder, Colo. — June 22, 2022 — Recreation at Gross Reservoir will remain closed for multiple weeks following the June 18 fatal accident at the Gross Reservoir Expansion Project where an engineer with six years of experience lost his life. This is essential as crews...

read more

Gross Reservoir recreation closed until further notice

Boulder, Colo. — June 18, 2022— Emergency responders are working on an accident that took place overnight at the Gross Reservoir Expansion Project site, in which a construction haul vehicle veered off the road into the reservoir. First responders and other agencies...

read more

May 2022 Recreation Update

May 26, 2022 - As a reminder, some recreation areas have closed or been relocated to ensure safety during the Gross Reservoir Expansion Project. The overall recreation experience will also be different throughout the project. Below are some of the changes and things...

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Thank You Supporters