1950s Gross Dam and its Expansion

(Satellite)

Mary Lahmann, Apr 2020

anderson amaya, Sep 2020

Oliver Novi, Oct 2020

R B, Feb 2018

CivilGEO Inc. Software posted, Photo courtesy Denver Water

Judge Halts $531M Gross Dam Expansion in Colorado

A federal judge has ordered a stop to Denver Water’s $531M Gross Dam expansion, citing improper permitting by the U.S. Army Corps of Engineers. With the project 60% complete, the ruling threatens water security for 1.5M people and underscores the growing challenges of building critical infrastructure amid environmental litigation.

Read more: https://www.enr.com/.../59980-judge-halts-construction-on... [the link took me to a different article]

DenverWater
When the dam was designed in the 1950s, it was designed to have additional phases of added capacity. They are now implementing those plans for expansion. "The project will raise the height of the existing dam by 131 feet [40m]. This will almost triple Gross Reservoir’s capacity, from approximately 42,000 acre-feet to 119,000 acre-feet."

Facebook Reel

Dec 2025: 5:51 video

Sep 2026:

Save The World's Rivers posted

SAVE THE COLORADO STATEMENT ON GROSS DAM RULING

Today, the 10th circuit court of appeals overturned the district court opinion on the Moffat Collection System Project (Gross Dam in Boulder County, CO), and now the project is allowed to be finished.

"It's nonsensical to be putting more straws in, and further draining, the Colorado River at this point in history. That the law allows it to happen doesn't make it right, it just makes it legal. I saw something wrong, I stood up, spoke out, and took action. It was the right thing to do, and I would do it all over again." -- Gary Wockner, Director, Save The Colorado

Sep 16, 2026:

Bernard Construction posted
On the Gross Reservoir Expansion Project, the last few months following the completion of roller-compacted concrete (RCC) in June 2026 have remained fast paced, with new self-perform and subcontract scopes taking off. The team is on track to have the batch plant down and the majority of load out completed in the coming month. On the structures front, crews completed additional placements within the stilling basin that facilitated the next phase of excavation activities, as well as the start and completion of the temporary soil nail walls. The soil nail walls will allow for full excavation for the left abutment retaining wall, while preserving existing penstocks to the valve house and powerhouse. Excavation is nearing completion, with the crew set to start foundation cleaning and dental placements for the retaining wall in the coming weeks. The new ogee and spillway bridge have also taken off. The crews are on track to have seven of the nine ogee blocks, the left and right bridge abutments, and the lower sections of the two intermediate bridge piers completed by the month’s end.