gross reservoir

Gross Reservoir Expansion Update

Denver Water attained final federal approval for their Gross Reservoir Expansion Project in mid-July.

The Federal Energy Regulatory Commission ordered Denver Water to proceed with design and construction to expand Gross Reservoir in Boulder County, which involves raising the dam an additional 131 feet. This will increase the capacity of the reservoir by 77,000 acre-feet and provide an additional 25 billion gallons of water storage.

Denver Water says the additional storage capacity will help prevent shortages during droughts and help offset an imbalance in the utility’s collection system. Extra water can be captured during wet years to aid in avoiding shortages during droughts.

“We are seeing extreme climate variability and that means we need more options to safeguard a reliable water supply for 1.5 million people in Denver Water’s service area,” said Denver Water CEO/Manager Jim Lochhead.

Located 12 miles southwest of Boulder in Coal Creek Canyon, the expansion project has been in the planning and permitting stage for 17 years. After the design work is complete, construction is expected to take four years. Denver Water anticipates project completion in 2025.

For all information pertaining to the Gross Reservoir Expansion project including cost, construction planning and progress, and community responsiveness, visit Denver Water’s webpage