Update 12/20 9:07 a.m.: This story was updated to include comments from Denver Water.
A handful of environmental groups have filed a lawsuit to halt construction on an expansion of Gross Dam in the Boulder County foothills.
Denver Water is proposing to increase the dam’s height by more than 130 feet to store more water from the Colorado River’s headwaters in the reservoir. The suit filed in Denver’s U.S. District Court alleges the construction project would negatively affect the Colorado River, harming native, endangered fish. The suit also argues the proposal runs afoul of the Clean Water Act.
“The Colorado River is in crisis,” Jen Pelz, wild rivers program director at WildEarth Guardians said in a statement. “The most obvious solution to sustain our namesake river is to start living within our means, not doubling down on what got us here in the first place—more reckless dams and diversions.”
Top officials with the Department of Interior, the U.S. Fish and Wildlife Service, and the U.S. Army Corps of Engineers are named in the lawsuit.
Denver Water CEO Jim Lochhead said he will support those federal agencies through the lawsuit, and is determined to see the dam expansion through to completion.
“In the last 15 years, we’ve come close to running out of water on the north end of our system," Lochhead said in a statement. "And, coming off another hot, dry year, filled with catastrophic wildfires across the state, the urgency for Denver Water to strengthen the north end of our water system has only intensified."
The lawsuit’s filing comes as no surprise. In August the environmental groups filed a notice of their intent to sue over the dam expansion and gave the federal agencies involved a 60-day notice.
The environmental groups involved include Save the Colorado, WildEarth Guardians and the Sierra Club.
A similar concurrent lawsuit has been filed to halt construction of Chimney Hollow reservoir in Larimer County as part of Northern Water’s Windy Gap Firming Project.
This story is part of a project covering the Colorado River, produced by KUNC and supported through a Walton Family Foundation grant. KUNC is solely responsible for its editorial content.