A coalition of six environmental advocacy groups followed through on a previously stated intention Wednesday by filing a lawsuit at U.S. District Court in Denver challenging the decision of the U.S. Army Corps of Engineers to issue a permit for expansion of Gross Reservoir in southwest Boulder County.

The project, which is being pursued by Denver Water and would be the largest construction project in the history of Boulder County if it were to go through, is known officially as the Moffat Collection System Project.

Denver Water, which serves 1.4 million customers in the Denver metro area ,but very few in Boulder County, had hoped to start construction next year on the project, which would raise Gross Dam by 131 feet to a height of 471 feet, and increase the capacity of the reservoir by 77,000 acre feet. It has been estimated that construction would require the removal of as many as 650,000 trees from about 12.5 miles of shoreline, although some estimates have put that at a lower number.

The project was issued a permit by the U.S. Army Corps of Engineers on July 7, 2017, leaving only a license amendment needed from the Federal Energy Regulatory Commission in order to go forward. That is still pending, but could be ruled on at any time.

“We’re alleging they violated the National Environmental Protection Act and the Clean Water Act and the Endangered Species Act,” said Gary Wockner, director of Save the Colorado, the lead plaintiff in the suit.

“In layperson’s terms, one is that Denver Water doesn’t need the water. Two is that they failed to look at reasonable alternatives, and three is that they are causing so much damage that they have failed to address or adequately mitigate the damage the project would cause.”

Other plaintiffs in the 57-page complaint are The Environmental Group, WildEarth Guardians, Living Rivers, the Waterkeeper Alliance, and the Sierra Club.

Named as defendants along with the Corps of Engineers is U.S. Secretary of the Interior, Ryan Zinke, and Margaret Everson, acting director of the U.S. Fish and Wildlife Service. It was recently reported that Zinke will be stepping down from his post at the end of the year.

“The remedy that we’re asking for is for them to stop the project and focus on alternatives,” Wockner said. “By their continued insistence to do this massive environmentally damaging dam expansion that further drains the Colorado River, the only remedy we consider is that they stop.

“Denver Water has lots of alternatives to address their needs, and they have purposefully chosen not to do those and instead tried to further drain the Colorado River.”

Tom O’Hara, director of public affairs for the Corps of Engineers’ Omaha district office, said, “Unfortunately, Corps policy is we don’t comment on ongoing litigation.”

The Department of Justice also declined comment, on behalf of the targeted federal agencies.

Conflict with the county, too

Denver Water CEO Jim Lochhead said it’s important that the expansion project not be sidetracked.

“We’re moving forward with the project,” he said. “We’re in a situation where we’re looking to secure our ability to continue to deliver water to 1.4 million people in our service area.

“We’ve had a couple of times in the last 15 years where we have come very close to running out of water in the north end of the system. We are overly dependent on the south end, and we are literally one catastrophic event or one drought away” from not being able to serve all customers. “We need to move forward with this project. This project is vital to our ability to continue to deliver water.”

The project is also subject to an ongoing dispute between Denver Water and Boulder County over whether the project also needs to go through what is known as the county’s “1041” land use review process. The county has contended that it is required to do so, while Denver Water believes it is exempt.

“It continues to be our position that the 1041 process does not apply to us, given our previous zoning status,” Lochhead said.

“That having been said, we continue to be committed to work with county and local residents to responsibly deal with the construction impacts of the project. We recognize this is a major construction process. We want to do the right thing by the local community, through continued outreach, listening and communication.”

Boulder County Land Use Director Dale Case issued a finding Oct. 22 stating that Denver Water needed to go through the county review process, and Denver Water subsequently requested a reconsideration of that decision.

“We’re still working on their request for reconsideration and we expect to have something, hopefully, after the holidays,” Case said Wednesday. “We’re looking at different options on how to respond, and to make sure we have local review authority over the project.”

Assistant Boulder County Attorney Conrad Lattes said “My understanding of the status is that they (Denver Water) asked for the Land Use Department to reconsider Director Case’s decision, and we have that under consideration.

“And while that is under consideration, we are also talking to them about finding a way to resolve these issues by negotiating what kind of a process they go through.”

Case had no comment on the filing of the lawsuit, saying he had not yet had a chance to review it.

‘Explosives, big trucks and machinery’

Denver Water’s Gross Reservoir plans call for diversion of additional water from the headwaters of the Colorado River, transport in the existing Moffat Tunnel through the Continental Divide, and release into South Boulder Creek for storage in the proposed expansion of Gross Dam and Reservoir. The project will triple the storage capacity of Gross Reservoir.

“Denver Water’s proposal to build the largest dam in Colorado history will hurt the 40 million people in 6 states and 2 countries who depend on the Colorado River — a critical but disappearing, resource — for their water supply,” Daniel E. Estrin, general counsel and advocacy director at Waterkeeper Alliance, said in a statement.

“Waterkeeper Alliance stands united with our many Colorado River Basin Waterkeepers who are fighting to protect their waterways and their communities from this senseless and destructive project.”

Trout Unlimited was one advocacy group taking the other side of the argument, asserting that collaboration between Western Slope communities, conservation interests and water users offers the Colorado River its best hope.

“The extensive mitigation and enhancement measures negotiated to benefit the Fraser and Upper Colorado hinge on approval of the Moffat Firming Project, and so we hope to see that approval move forward,” said a statement issued by the organization.

The progress of the project has been monitored closely by those living close to Gross Reservoir, who fear a range of adverse effects, both short term and long term, should it go forward. Many of them live in Coal Creek Canyon, and have come together under the umbrella of The Environmental Group.

“For those of us who live close to Gross Reservoir, we will lose everything we moved here for: wild pristine beautiful scenery, clean air, clean water, boating, fishing, peace and quiet,” Celena Collins president of The Environmental Group, said in a statement.

“It is imperative that (we) preserve the pristine beauty of our mountain range and protect all that dwell within it, but this project would make that impossible. The construction associated with the expansion of the reservoir will bring explosives, big trucks and machinery, pollution, toxic coal fly ash, and will destroy more than 200,000 trees which provide critical wildlife habitat and ecosystem services like erosion prevention.”

Lochhead said Denver Water refutes such arguments, stressing Denver Water’s partnership on water conservation with a number of counties on both sides of the Continental Divide, and contends expansion would provide “a net benefit” in the state.

“We’ve been in a permitting process for 15 years,” Lochhead said. “We’ve been looked at by the Corps, the (Federal Energy Regulatory Commission), by the Colorado health department, the U.S. Fish & Wildlife Service, state agencies, Colorado Parks & Wildlife, the Colorado Water Conservation Board, the forest service, the EPA.

“This project has been studied, and the conclusions are pretty clear that the environmental impacts have been dealt with.”

Charlie Brennan: 303-473-1327, brennanc@dailycamera.com or twitter.com/chasbrennan