Overview of Gross Reservoir Expansion Project
Learn about Denver Water's Gross Reservoir Expansion Project with Jeff Martin, Denver Water's program manager.
On-water recreation has closed for the 2025 season. Hiking, picnicking and other off-water recreation remains open. Additional information, including traffic control and road restrictions, can be found on MyMap.
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.
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.