DENVER, Colo. (CBS4) – The Army Corps of Engineers announced approval of a Denver Water Department project that plans to almost triple the capacity of Gross Reservoir.
“The additional water stored in Gross Reservoir will help prevent future shortfalls during droughts and helps offset an imbalance in Denver Water’s collection system,” a news release from Denver Water announced.
Gross Reservoir sits six miles southwest of Boulder and currently holds 41,811 acre-feet behind a dam built in the 1950s.
The proposed project raises the dam’s height from 340 to 471 feet, and increases the reservoir’s storage capacity by 77,000 acre-feet.
The dam, according to Denver Water, was originally designed and built with a future expansion in mind.
“The Gross Reservoir Expansion Project approval completes this original vision,” states the release.
The reservoir receives flow from the Fraser River, Williams Fork River, and South Boulder Creek.
The Federal Energy Regulatory Commission still needs to amend Denver Water’s hydropower license before the project is clear to begin.
Denver Water predicts pre-construction activities, including dam design and geotechnical work, to begin in 2018. The entire project is expected to be completed in 2025.
The Associated Press reports the project will cost $380 million.
One acre-foot of water (1,200 cubic meters) can supply two typical households for a year.
(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)