Amanda Pampuro

DENVER (CN) — A Colorado environmental group sued the U.S. Army Corps of Engineers in federal court Thursday to stop a planned dam and reservoirs off the Cache La Poudre River which flows along the northern Front Range from Larimer County into the South Platte River.

The Larimer County-based group, Save the Poudre, argues the federal government adopted an arbitrary water-capture goal and shirked its responsibilities to conduct a thorough environmental impact assessment of the Northern Integrated Supply Project.

"We were founded 20 years ago to fight against this project," said Gary Wockner, executive director of Save the Poudre. "The project that was proposed 20 years ago was estimated to cost $143.9 million. And last January when the record of the decision came out, they said it was going to cost $2.25 billion."

The project was first proposed among 15 water providers in 2002 to secure part of a projected water need of 40,000 acre-feet. The plan has since grown to include a dam diverting 40,000 acre-feet of water annually into the Glade Reservoir northwest of Fort Collins. At the end of construction, Glade Reservoir will have an estimated capacity of 170,000 acre-feet and the Upper Galeton Reservoir northeast of Greeley is expected to hold along 45,624 acre-feet.

“The ecological impacts will be astounding. Construction and operation of Northern Integrated Supply Project would permanently degrade important riparian habitat, alter and degrade water quality and circulation, [and] contribute to the loss of significant environmental values,” the group says in its 67-page complaint.

The group estimates the filling the Glade Reservoir would mean diverting 35% of a river already taxed by population growth, climate change and decreased snowpack.

The group lists environmental concerns as well as economic impacts on surrounding farmers and the recreation industry. In addition to disrupting habitat for the threatened Preble’s meadow jumping mouse, the complaint said alterations will disrupt fish feeding grounds and other sensitive species.

The environmental group contends the federal government arbitrarily adopted 40,000 acre-feet as a floor for any proposed alternatives.

The Northern Colorado Water Conservancy District has not been named as a party in the suit but played a significant role in coordinating the project to secure water to meet local projected needs through 2060.

“Northern Water has not had the opportunity to explore the issues set forth in the action against the federal government but we are confident in the thorough work performed by the Army Corps of Engineers that the permit issued to Northern Integrated Supply Project will be affirmed based on the detailed work done over the years, and extensive mitigation being included,” said Jeff Stahla, public information officer for the water district, on a call.

The project is currently in the final design stages, with construction slated for 2025 and Glade Reservoir completed before the end of the decade.

Citing violations of the Administrative Procedure Act and the National Environmental Protection Act, Save La Poudre asks the court to block the Corps’ 404 Permit and enjoin the project until the government has fulfilled the laws’ requirements.

A similar lawsuit pending before a state appellate court between No Pipe Dream and Larimer County challenges local-level land use permits for the water project.

Save the Poudre is represented by attorney Jessica Townsend of the DC-based firm Eubanks and Associates.

Representatives for the U.S. Army Corps of Engineers did not respond to a request for comment before publication.