Chimney Hollow Reservoir comment period extended

By Cherry Sokoloski
North Forty News

Northern Colorado is awash in large water projects, all in various stages of planning and looking for permits from federal agencies in order to proceed.

The projects are intended to satisfy municipal water demands along the Front Range, from Fort Collins and Loveland to fast-growing communities like Frederick in southwestern Weld County.

The best-known project is the Northern Integrated Supply Project, which could include Glade Reservoir northwest of Fort Collins (see article on this page). Others in the pipeline are the Halligan-Seaman project on the North Fork of the Poudre River, a project that would benefit Fort Collins, Greeley and a few other entities; and the Windy Gap Firming Project involving a new reservoir west of Carter Lake.

Some communities are participating in more than one proposed water project to shore up domestic water supplies.

The Windy Gap Firming Project is in the most active state at present in terms of public involvement. Its comment period was originally set to close in late October but was recently extended to Dec. 29. This project, which calls for a new reservoir west of Carter Lake, would benefit some Larimer County water users, including Loveland, as well as other Front Range communities. It would also afford some recreational opportunities.

Since the project would adversely affect the Colorado River on the Western Slope, many on that side of the Continental Divide have voiced strong opposition.

Chimney Hollow site

The Windy Gap Firming Project proposes construction of Chimney Hollow Reservoir just west of Carter Lake. Larimer County and the Northern Colorado Water Conservancy District each purchased portions of the Chimney Hollow property in 2004.

The draft EIS for the Windy Gap Firming Project was released in late August. The project would provide more storage for Colorado River water from the Western Slope. Windy Gap Reservoir near Granby was completed in 1985, but storage has not been sufficient for all the water that can legally be captured.

In the water business, "firming" means making a water supply more reliable. The Chimney Hollow Reservoir would provide more "firm" yield to Windy Gap project participants. Because of insufficient storage capacity now, these water users see some of the water they own go down the river without being used.

As proposed, Chimney Hollow Reservoir would have a capacity of 90,000 acre-feet, compared with Carter Lake's 112,000 acre-feet. Communities that would benefit from the new water storage include Loveland, the Little Thompson Water District, Greeley, Longmont and 10 other participants along the Front Range. Public recreation, including non-motorized boating, would be allowed on the reservoir.

Two public hearings were held in October for the Windy Gap project, one in Loveland and the second in Granby on the Western Slope. The Front Range hearing was quiet with little discussion or dissension, according to Chandler Peter of the U.S. Army Corps of Engineers.

West-slope concerns

What a difference a continental divide makes, however. Western Slope residents would be affected by the project but wouldn't benefit from it, and the public hearing in Granby reflected that fact.

"About 99 percent of the people at the Granby hearing were totally opposed to the project," Peter said.

Western Slope concerns are similar to those voiced at NISP hearings; only the name of the river has changed. With NISP, citizens are concerned about impacts on the Poudre River. With the Windy Gap Firming Project, it's the Colorado River that would be affected - along with three Western Slope reservoirs.

As planned, the Windy Gap water would flow through Lake Granby, Shadow Mountain Reservoir and Grand Lake before being transported through the Adams Tunnel to Chimney Hollow Reservoir.

Western Slope communities are worried about lower water levels in the Colorado River, as well as poorer water quality in the river and the reservoirs. Since several communities rely on the economic value of recreation at the three reservoirs, the firming project "could have socio-economic impacts" on the area, Peter noted.

The Larimer County Commissioners have already provided input on the Windy Gap Firming Project. Their comments were generally positive, but they did express concern that water levels at Horsetooth Reservoir would be lower if more water were stored in Chimney Hollow. Project manager Jeff Drager of NCWCD said the system could be operated to keep Horsetooth levels "closer to normal" than the computer modeling showed.

If Chimney Hollow Reservoir is built, Larimer County plans to manage recreation on and around the reservoir. Recreational opportunities would include 10 miles of multi-use trails, a boat ramp and picnic areas. The reservoir would be the largest nonmotorized recreation reservoir in the state.

Estimated cost of the Chimney Hollow reservoir is $270 million, according to the NCWCD. The primary permitting agency for the Windy Gap Firming Project is the U.S. Bureau of Reclamation. The Army Corps is involved with the project because water-quality permits are also required.

The Bureau of Reclamation estimates that a final EIS could be ready by spring 2009.