Gross Reservoir Expansion Project

The Gross Reservoir Expansion Project is a major component of Denver Water’s long-term, multi-pronged approach (including promoting water efficiency, recycled water and responsible sourcing of new supply) to deliver safe, reliable water to the more than 1.4 million residents in our service area today and many of the projected 7.7 million who will call Colorado home by 2040.

The project will raise the height of the existing dam by 131 feet, which will allow the capacity of the reservoir to increase by 77,000 acre feet. Once permits are secured, we expect the construction to take place in three phases over a total of four to five years:

  • First we will mobilize equipment and develop aggregate materials (sand and gravel) at an on-site quarry. This first phase will also include establishing the construction site, project offices and readying the existing dam and abutments.
  • That will be followed by dam construction, which we expect will take approximately three years, during which most of the work will occur during spring, summer and fall months.
  • Once the dam is complete, the final phase will begin, which involves removal of trees and brush from the new inundation footprint.

The additional water storage will help prevent future shortfalls during droughts and helps offset an imbalance in our North-South collection system. With this project, we will provide water to current and future customers while providing environmental benefits to Colorado’s rivers and streams.

Denver Water is working with communities we are likely to impact during all phases of the project. We continue to listen to concerns and have made significant commitments to adjust our practices to minimize inconvenience to the local community. We are sensitive to the concerns of stakeholders and are committed to being a good neighbor. Starting in fall 2017, we opened a community welcome and information center at Gross Reservoir. The public information yurt, which is open seasonally and staffed between 5 and 7 days a week, is intended to provide a welcoming space where members of the local community and recreationists can stop and learn more about the project, express concerns and share experiences. We’re hopeful that this dedicated, more regular presence in the community will enable us to open lines of communication and increase understanding from all perspectives.


Latest News

Surveyors in the field

You may have noticed surveyors taking readings on Gross Dam Road from the intersection of Highway 72 to the right abutment of Gross Dam. This work – scheduled to be completed by the end of this month – is part of our ongoing efforts to improve safety for all who drive...

Thank you tour participants!

Our thanks to all who joined us for a tour of the Gross Reservoir Expansion Project on Oct. 5. Staff from Sen. Gardner and Sen. Bennet’s offices, representatives from Denver Water distributors and the South Metro Chamber of Commerce, among others, joined...