Click the link to read the article on the Denver Water website (Jay Adams):
July 20, 2026
Denver Water’s Gross Reservoir Expansion Project reached a milestone in June as workers completed major construction on raising the dam.
On June 3, 2026, workers placed the final load of roller-compacted concrete on the top of the dam, bringing Gross Dam to a height of 470 feet. Roller-compacted concrete is the type of concrete put in place to raise, thicken and lengthen the dam over the past three years.
The project is designed to nearly triple the capacity of Gross Reservoir, increase Denver Water’s reservoir storage capacity by 11%, and provide balance, resiliency and flexibility to the utility’s water collection system.
Additional work to complete the dam will take place over the next year, including adding one more foot of conventional, protective concrete to the top of the dam, which will bring it to its final height of 471 feet above the valley floor below.
At this point, dam is taller and also has a new shape.
“We have fundamentally changed how this dam works. The old Gross Dam was a gravity dam that held back the water by its sheer weight. We’ve now transformed this into an arch dam which holds the water back by its weight and also transfers the loads laterally like a Roman arch. This is the first time that we know that this dam transformation has ever been done in the world.”
In the video above, you can see new images of the dam and hear from Jeff Martin, Denver Water’s program manager for the project.
“We’re excited and proud of this accomplishment,” Martin said.
“Hundreds of people helped us reach this milestone, which will provide a secure water future to Denver and the surrounding communities.”
