Click the link to read the article on the Denver Water website (Jay Adams):
May 22, 2026
Each stage of a big construction project has its own challenges and puzzles to solve along the way. Raising Gross Dam is no different.
Denver Water is raising the height of the dam by 131 feet, with the final 22 feet going up this spring in two sections that are separated by a giant gap. The Gross Reservoir Expansion Project, which began construction in 2022, is designed to nearly triple the reservoir’s storage capacity. Major construction work resumed in April following a winter break.
And this year’s construction puzzles included:
- How to move concrete across a 160-foot gap between where the concrete is made and where it’s placed?
- And, how do you move construction vehicles across that same gap when work on the first section is finished?
“We are building the top of the dam in two sections because we need to leave a 160-foot gap in the middle of the dam for the spillway channel,” said Casey Dick, Denver Water’s deputy program manager for the Gross Reservoir Expansion Project.
Spillway channels are safety features on dams that allow water to safely flow out of a reservoir if needed due to flooding rains or exceptionally high and rapid snowmelt.
Raising the dam’s last two major sections, while leaving a 160-foot gap between them, meant coming up with a new way to move concrete across the construction site.
On the lower portion of the dam, crews worked on one continuous structure, which allowed trucks and equipment to easily move from one side of the dam to the other, and to move concrete from the batch plant down a large chute to where it was put into place.
However, with the final 22 feet going up in two sections, construction crews had to find a way to deliver concrete from the batch plant and across the 160-foot spillway gap as the first section went up.
The solution to this puzzle? A series of conveyors positioned in the middle of the dam that tilted higher as the first section rose higher.
“Building the new conveyor system is just another example of all the ingenuity we go through out here to build the dam,” Dick said. “With each new phase, there are new challenges that our team has to figure out.”
Construction crews finished placing roller-compacted concrete on the dam’s left side on May 12.
But once that was done, crews faced the second challenge: How do you move the equipment off the finished, 22-foot higher section of the dam, across the spillway gap, down to where they are needed to complete the second section?
Short answer: If you can’t go over, go around.
Cranes lifted equipment off the higher section of the dam to the road, where the machines convoyed about 4.5 miles around to the other side using the dam’s access road.
Construction on the final 22 feet of the second side of the dam began at the end of May and is expected to be completed in June.
Once the second section is done this summer, a year’s worth of remaining work includes: finishing the top of the dam, building safety walls; constructing the actual spillway; building a bridge over the spillway and completing the stilling basin at the bottom of the dam.
Full construction on the dam raising project is expected to wrap up in mid-2027.
“There are hundreds of logistical challenges throughout this project, but our team has been able to meet every one of them along the way,” Dick said. “We’re making good progress so far in 2026 and are looking forward to getting a lot of work done in the coming months.”
