Waterkeeper Alliance Celebrates Major Legal Victory Against Colorado’s Gross Dam Expansion Project
By: Waterkeeper Alliance
The United States District Court for the District of Colorado granted Waterkeeper Alliance and its co-petitioners—Save the Colorado, The Environmental Group, WildEarth Guardians, Living Rivers, and Sierra Club—another important legal victory against the U.S. Army Corps of Engineers and Denver Water, blocking the expansion of the Gross Dam and Reservoir in Colorado, part of Denver Water’s Moffat Collection System. The petitioners are represented by Eubanks & Associates, PLLC.
In October 2024, the court granted summary judgment to the groups, finding that the Corps of Engineers had violated the federal Clean Water Act and the National Environmental Policy Act (NEPA) when it issued a Clean Water Act dredge-and-fill permit to Denver Water for the project. Yesterday’s ruling involved how the Corps will be required to remedy its violations of the law. The Corps and Denver Water pushed for a simple remand to the Army Corps without nullifying the permit, which could have allowed continued construction notwithstanding the serious legal violations the court had identified. The conservation groups requested an injunction blocking further construction of the dam and expansion of the reservoir and nullification (also known as vacatur) of the permit and of the entire NEPA process because it was so legally flawed.
The court has now ruled in favor of the groups, finding that the Corps committed “serious errors” when it permitted the project, and that the Corps and Denver Water had presented “disingenuous arguments that oversimplify and misrepresent the larger scale of the [project] and the Corps’ authority.” The court further noted that Denver Water’s arguments about alleged cost, delay, and the urgent need to address droughts, were “not persuasive because these alleged hardships [were] largely self-inflicted” since Denver Water had commenced construction with full knowledge that the groups were challenging their Clean Water Act permit in court.
“We’re relieved that the court has now blocked expansion of the Gross Reservoir and all the damage to communities in Boulder County and the environment that the expansion has and would have continued to cause,” said Daniel E. Estrin, General Counsel and Legal Director for Waterkeeper Alliance. “The court recognized that the Army Corps’ permitting process for this project was fundamentally flawed, and that the grave errors the Corps committed could not be cured by a simple remand, which would have allowed Denver Water’s destruction to continue. We are grateful that the Court performed the careful review of the administrative record necessary to grant summary judgment to petitioners in this case, and that it has now selected the only appropriate remedies under these circumstances: injunction and vacatur of the permit and NEPA documents.”
The proposed Gross Reservoir Expansion Project, which would have destroyed over 400 acres of vital forest land and more than 500,000 trees, obliterated wildlife habitats, diverted precious water from already fragile river ecosystems, and created unbearable nuisance conditions for nearby communities, has now been completely blocked by the court and cannot move forward. The project, if it is ever completed, would result in the tallest roller-compacted concrete dam in the United States, exacerbating the already critical water shortage situation in the Colorado River Basin, which serves 40 million people and ecosystems across seven states. As the region grapples with heightened water demand and dwindling supply, this ruling sets a crucial precedent confirming the obvious need for the government to comply with federal law when it permits destructive projects.
