By Rick Sallinger and Kerry O’Connor

BOULDER COUNTY, Colo. (CBS4) – Water in the western United States is liquid gold and Gross Reservoir in Boulder County is a gold mine. A decades-long battle involving federal, state and local governments is winding down as Boulder County and Denver Water finally come to an agreement.

Gross Reservoir (credit: Denver Water)

It will take five years, but when completed the dam will be 131 feet higher and Gross Reservoir will hold far more water.

Jim Lockhead, the CEO of Denver Water acknowledged the agreement with the Boulder County Commissioners came after a long dispute.

“I recognize that this was a hard and emotional decision by the Boulder County Commissioners. There was a lot of really intense feeling and opposition by local residents about the impacts of construction and the environmental impacts of the construction,” Lockhead said.

The Board of Denver Water has now approved the agreement reached with the Boulder County Commissioners a day earlier. Signs in the area of the reservoir above and outside of Boulder read, “Stop Gross Dam Expansion.” This battle has been going on two decades.

Copter4 flew over Gross Reservoir (credit: CBS)

Tim Guethner who lives near the reservoir expressed his opposition to CBS4’s Rick Sallinger this past summer, “This construction project would destroy the natural characteristics of this area.”

Part of the reservoir used for recreation will be blocked off, but remain open away from the dam. The agreement comes after Denver Water sued the Boulder County Commissioners in federal court to speed the approval process.

Claire Levy is one of the commissioners who opposed the dam expansion.

She told CBS4, “None of us commissioners like this project either. We think it’s bad for the environment and it is going to have a tremendous impact on the residents.”

What Boulder gets out of the deal is $13 million to go towards mitigating problems the project will create.

(credit: CBS)

Lockhead said of the agreement, “This is a tremendous improvement to the security and reliability of our water system.”

Bev Kurtz, another area resident, predicted in July, “The noise is going to be unbelievable, The traffic from construction workers. The explosions from blowing up that mountain to level it. The animals will leave, it’s going to be a real circus.”

There is still one possible obstacle. A group called “Save the Colorado” is deciding whether to continue its so far unsuccessful efforts to block the dam expansion in court.