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Gross Reservoir Expansion Project

Construction is underway

Construction for the Gross Reservoir Expansion Project started April 1, 2022. The project will raise the height of the dam by 131 feet, tripling the reservoir’s capacity from approximately 42,000 acre-feet to 119,000 acre-feet.

When complete, the reservoir, located in western Boulder County, will be Denver Water’s second-largest and will provide essential flexibility and resiliency to our customers in the face of increasing impacts from climate change.

It will take five years to finish the work to raise the height of Gross Dam. Photo credit: Denver Water.

We will update our construction page with information about activities on-site. You can also stay connected by signing up for our e-newsletter or following us on social media. Want to talk to a project representative? Sign up for a one-on-one appointment, in-person or virtual, on our contact page.

Overview of Gross Reservoir Expansion Project

Learn about Denver Water's Gross Reservoir Expansion Project with Jeff Martin, Denver Water's program manager.

Enlarged Gross Reservoir addresses system imbalance

The additional reservoir capacity will enable increased water capture in wet years to help avoid shortages during droughts.