Proposed reservoir, pipeline, exchange could have impacts to fish and environmental flows
- By Heather Sackett, Special to the Planet
Water users in Ouray County are hoping to satisfy water shortages with what they say is a multi-beneficial reservoir and pipeline project. But the Ram’s Horn reservoir, Cow Creek pipeline and exchange are facing opposition from the state of Colorado and others.
The complicated, three-pronged project proposes to take water from Cow Creek and pipe it into Ridgway Reservoir, take water from local streams via ditches and store it in the reservoir, and build a new dam and reservoir on Cow Creek. This stored water would eventually be sent downstream to be used by the Uncompahgre Valley Water Users Association (UVWUA).
The project applicants — Ouray County, Tri-County Water Conservancy District, Ouray County Water Users Association and the Colorado River Water Conservation District — say they need 20 cubic feet per second of water from Cow Creek. Cow Creek is a tributary of the Uncompahgre River with headwaters in the Cimarron mountains. Cow Creek’s confluence with the Uncompahgre River is below Ridgway Reservoir, which is why an upstream pipeline would be needed to capture the water and bring it into the reservoir.
The applicants are also seeking to build Ram’s Horn Reservoir on the upper reaches of Cow Creek, which would hold about 25,000 acre-feet of water behind a 260-foot-tall and 720-foot-long dam. Ram’s Horn would help regulate what are known as diurnal flows during spring runoff — streamflows are higher during the day as the snow melts with warming temperatures, and lower at night as snow re-freezes. UVWUA says they can’t adjust their headgates to capture the high point of this daily fluctuation in flows, leaving the water to run downstream unused. The project would capture these diurnal peaks.
Goal to prevent a call
The goal of the project is to prevent the UVWUA — one of the big senior water rights holders in the Gunnison River basin — from placing a call on the river.
When the UVWUA, which owns the Montrose & Delta Canal and has a 1890 water right, is not able to get its full amount of water, it places a call on the river. This means upstream junior water rights holders, like Ouray County Water Users, have to stop using water so that UVWUA can get its full amount. According to a state database, the M&D Canal has placed a call three times this summer, most recently from July 12 to 22. In 2020, the call was on for nearly all of July and August. Under Colorado water law, the oldest water rights have first use of the river. https://www.telluridenews.com/tncms/block/1798244/?disableTNStatsTracker=1
By releasing the water stored in either Ridgway or Ram’s Horn reservoirs to satisfy a UVWUA call, Ouray County Water Users Association would then be able to continue using its own water.
The Glenwood Springs-based River District, which advocates to keep water on the Western Slope, is a co-applicant of the project.
“This (project) is consistent with the River District’s goals and objectives with supporting our constituents and making sure they have a reliable water supply,” said Jason Turner, River District senior counsel. https://www.telluridenews.com/tncms/block/1798244/?disableTNStatsTracker=1
Potential impacts to fish, instream flows
But some state agencies, environmental groups and others have concerns about the project. Colorado Parks and Wildlife and Colorado Water Conservation Board have both filed statements of opposition to the application, which was originally filed in December 2019, amended in January and is making its way through water court. CPW claims that its water rights in the basin, which it holds for the benefit of state wildlife areas, fisheries and state parks, could be injured by the project. CPW owns nearly a mile of access to Cow Creek on the Billy Creek State Wildlife Area.
Between August 2019 and January 2020, CPW recorded water temperatures of Cow Creek and found they exceeded a state standard for trout. A report from CPW aquatic biologist Eric Gardunio says that the proposed project would likely cause an even bigger increase in water temperatures, resulting in fish mortality.
“The flow and temperature analysis for Cow Creek indicates that the water rights application has the likelihood to damage or eliminate the native bluehead sucker population as well as the rest of the fishery in the downstream end of Cow Creek through the degradation of water quantity and quality,” the report reads.
While less water in Cow Creek could result in temperatures that are too high for trout, water released from the proposed Ram’s Horn reservoir could be too cold for bluehead suckers. https://www.telluridenews.com/tncms/block/1798244/?disableTNStatsTracker=1
“There’s going to be some changes to temperature and what our temperature data has outlined is that the species are at their extreme ends,” Gardunio said. “It’s nearly too cold for bluehead sucker and it’s nearly too warm for trout, so changes in temperature are going to have an impact to one or the other of the fishery.”
The Colorado Water Conservation Board opposes the project because they said it could injure the state’s instream flow water rights. Instream flow rights are held exclusively by the CWCB to preserve the natural environment to a reasonable degree. Ram’s Horn reservoir would inundate a section of Cow Creek where the CWCB currently holds an instream flow right.
“The application does not present sufficient information to fully evaluate the extent to which the CWCB’s instream flow water right may be injured,” the statement of opposition reads.
Environmental group Western Resource Advocates also opposes the project. Ram’s Horn Reservoir, with conditional water rights owned by Tri-County Water Conservancy District, is one of five reservoirs planned as part of the U.S. Bureau of Reclamation’s Dallas Creek Project, which dates to the 1950s. Ridgway Reservoir is the only one of the five that has been built. https://www.telluridenews.com/tncms/block/1798244/?disableTNStatsTracker=1
The third piece of the proposed project is what’s known as an exchange, where water would be conveyed via existing ditches connecting tributaries above Ridgway Reservoir. The exchange water would be stored there and released when senior downstream water users need it, which would benefit upstream water users. In addition to Cow Creek, the applicants are proposing to take water from Pleasant Valley Creek, the East and West Forks of Dallas Creek, Dallas Creek and the Uncompahgre River to use in the exchange.
Colorado Division of Water Resources Division 4 Engineer Bob Hurford laid out the issues his office has with this exchange in his summary of consultation. He recommended denial on the exchange portion of the application until the applicants list the specific ditches participating in the exchange and their locations, and agree that they are responsible for enlarging the ditches so they can handle the increased capacity of water.
“I have to have actual ditch names, the owners of the ditches have to be willing to participate and it has all got to be tracked to a tenth of a cfs,” Hurford said. “It’s not a loosey-goosey thing. It has to be dialed in and defined precisely.”
Another criticism of the project is that it won’t provide water directly to water users in Dallas Creek, which according to a report by Wright Water Engineers, is the most water-short region of the Upper Uncompahgre basin. Even if Dallas Creek water users participate in the exchange, in dry years still there may not be enough water in local creeks for them to use. https://www.telluridenews.com/tncms/block/1798244/?disableTNStatsTracker=1
“This project has been sold as the savior of agriculture in Ouray County but this project will not provide wet water that would not otherwise be available to anybody that is an ag producer,” said Ouray County water rights holder and project opponent Cary Denison. “I don’t know one irrigator who is saying we need to build Ram’s Horn Reservoir.”
The project application is making its way through water court and applicants say they are continuing to negotiate with opposers. A status report is due in October. Attorney for the Ouray County Water Users Association and River District board representative Marti Whitmore said they want to make sure it’s a multi-purpose project that benefits everyone.
“Fish flows and recreation uses are important, so we are just trying to work out terms and conditions that are a win-win for everyone,” she said.