Will Glade degrade Poudre?

By Cherry Sokoloski
North Forty News

Opinions diverge widely, much like the forks of a river, when it comes to Glade Reservoir.

Glade and a smaller reservoir, Galeton, are proposed as part of the Northern Integrated Supply Project which, if built, will supply domestic water to 16 communities and water districts in northern Colorado.

Glade, which would be larger than Horsetooth Reservoir, would be situated north of Ted's Place and would require moving U.S. Highway 287.

The environmental impact statement for NISP is due out this summer, probably in July, according to officials at the Northern Colorado Water Conservancy District, which is spearheading the project.

One primary point of contention about Glade has been the question of how diverting water to the reservoir would affect the health of the Cache la Poudre River. NCWCD officials claim they would be required to protect the riparian area and the wildlife that depends upon it. Some conservationists contend that by removing additional water from the Poudre, Glade would further degrade the river, harming both riparian life and water quality.

There is no question, both sides agree, that there will be less water in the river if Glade is built. The project would pull water off the river via two mechanisms: water exchanges with other water users; and the Grey Mountain water right which, because it's a junior right, would kick in only during years when there's plenty of water.

Water diverted

To fill Glade, NISP must pull water off the river at the Poudre Valley Canal, located at the mouth of the Poudre Canyon. To accomplish that, the partnership proposes exchanging water with other entities that normally pull water off further downstream and moving those diversions to the Poudre Valley Canal. In short, water would be diverted further upstream than it currently is.

As a result, said Carl Brouwer, project manager for NISP, "streamflows will generally be lower through town." The total difference in water volume through Fort Collins would be 24,000 to 26,000 acre-feet less per year because of moving the diversion points. The average total flow in the Poudre is 280,000 acre-feet per year.

Upstream of the canyon mouth, NISP would not have an effect on streamflow.

The water exchanges would happen with the Larimer & Weld Reservoir Co., which now diverts water upstream of Shields Street, and the New Cache Irrigation Co., which takes river water out near Interstate 25. In dry years there would be no water to exchange, Brouwer noted.

The second mechanism, the Grey Mountain water right, would provide water to Glade only in certain years and under certain circumstances. NISP is figuring on an average of 18,000 acre-feet per year from this source. Brouwer explained that several factors would determine whether this water right would come into priority: the entire volume of water available during the runoff period, whether there's a rainy spring, and how full the reservoirs are from the previous year.

As an example, if all those factors are positive and the Poudre peaks at 3,000 cubic feet per second (the historic average), NISP might be able to pull off 1,000 cfs during the peak runoff period.

George Varra, Poudre River commissioner, said the only average or better runoff since 1999 occurred in 2003, when the river peaked at 3,840 cfs. Peak runoffs have been unusually low in this decade because of the prolonged drought.

Minimum flow required

Brouwer said NISP would be required to maintain minimum flows at three locations. At the Bellvue Fish Hatchery, the expected requirement will be 50 cfs in summer, 25 in winter. At the bridge on North College Avenue and at the point where the river goes under Prospect Road, requirements would be 30 cfs both summer and winter.

"It limits us, but that's okay," said Brouwer. "We have to make sure the riparian area is protected." Brouwer said the NCWCD staff is trying to find innovative ways to keep as much water as possible in the river as it flows through Fort Collins. For example, it may be possible to move a couple of ditch diversion points further downstream.

Brouwer said he also expects the Army Corps of Engineers to require the creation of a low-flow channel in the river to give fish a place to go during dry periods. The Army Corps is the agency that decides whether to give NISP a permit.

While Brouwer has heard from many NISP detractors, he thinks environmentalists will be "amazed at the depth of analysis and what we're being required to do" in terms of keeping aquatic and riparian environments healthy.

Sierra Club concerned

Mark Easter, a member of the Poudre Canyon Group of the Sierra Club and a trained botanist, said the Sierra Club has four principal concerns about the Glade proposal and the further depletion of the Poudre River, especially the impact on peak flows. The organization is worried about wetlands along the river, the riparian forest of cottonwoods and willows, fish habitat and water quality.

"The peak flows in above-average years are the most important flows for maintaining the river's health," Easter contended.

Peak flows recharge the wetlands and the groundwater around the wetlands, he noted, and wetlands are critical for maintaining water quality since they filter out impurities. Wetlands also provide important wildlife habitat and recreation areas.

"If you lose the peak flows, you lose the wetlands," Easter said.

The riparian forest is also influenced by peak flows, Easter said. Trees drop their seeds at the time when water is receding, and they need scoured ground for the seeds to germinate.

For fish, Easter said, peak flows remove silt, creating spawning beds and a healthy habitat. Water quality is also affected by peak flows, since the big rush of water flushes out pollutants.

According to Easter, the local Sierra Club is pushing for two sustainable solutions to water needs in northern Colorado. First, members advocate the use of conservation practices by all water users. Second, they would like to see water users work together to manage the river in such a way that it can meet people's water needs while restoring the river's health. "We think it's highly possible" to meet those goals, Easter said.