BASALT – The lower Fryingpan River below Ruedi Reservoir has been flowing steadily at about 300 cubic feet per second since Aug. 12, when flows were increased by 50 cfs for the benefit of the endangered fish recovery program on the Colorado River below Palisade.
Flows in the Fryingpan are now expected to remain at about 300 cfs – 298 to 302 – at least until mid-September, according to Jana Mohrman, a hydrologist with the U.S. Fish and Wildlife Service, which manages the fish recovery program.
Fly-fishing guides on the Fryingpan River say many of their clients prefer when the river is flowing at 240 cfs rather than 300 cfs, because higher water makes it harder to wade.
But flows may also stay at the 300 cfs level throughout September, Mohrman said. They could be lowered back to 250 cfs, however, if conditions – temperature, precipitation, irrigation return flows, plant growth rates – allow at some point in September.
“We look forward to it and we hope it happens,” Mohrman said of returning to flows of 250 cfs in the ‘Pan.
If favorable conditions do arrive, it could make it easier for Mohrman to reach the targeted flows of 1,240 cfs in the Colorado River near Palisade without the additional 50 cfs from Ruedi that she called for on Aug. 11.
Mohrman manages a pool of “fish water” stored in Ruedi Reservoir that can be released to flow down the Fryingpan, Roaring Fork, and Colorado rivers.
The water from Ruedi contributes to the flows in critical fish habitat in a 15-mile reach of the Colorado River between Palisade and the confluence of the Colorado and Gunnison rivers in central Grand Junction.
But not all of the water coming out of Ruedi Reservoir is fish water.
Of the 298 cfs flowing out of Ruedi Reservoir on Aug. 31, for example, 186 cfs was fish water, 107 cfs was to offset inflow to the reservoir, and about 5 cfs was coming in below the dam from Rocky Fork.
This year, the Fish and Wildlife Service is expected to ask for the release of between 21,412 acre-feet and 24,912 acre-feet of fish water from Ruedi, which can store 102,373 acre-feet of water.
As of Aug. 31, 12,184 acre-feet of fish water had been released from Ruedi Reservoir, leaving between 9,228 and 12,728 acre-feet of fish water yet to be released, according to a “state of the river flow sheet” prepared by the Colorado Division of Water Resources as part of a weekly conference call held by regional water managers about the 15-mile reach.
(The range of how much fish water is left depends on whether the Fish and Wildlife Service decides to use 6,000 or 9,500 acre-feet of water available to it through a contract between the Colorado Water Conservation Board and Ute Water, a water provider in Grand Junction that owns the storage right to 12,000 acre-feet of water in Ruedi.)
At a release rate of 186 cfs a day, there would be enough fish water left in Ruedi for 25 to 34 days of releases, depending on how much water from the Ute Water contract is used.
But Tim Miller, a hydrologist at the Bureau of Reclamation who manages the flows from Ruedi, said the rate of incoming water to Ruedi can vary quite a bit, and when it drops, more fish water is released to hit the proscribed release flows.
As such, nature has another card to play in how many days of fish water are remaining in Ruedi. For example, fish water flows could be higher than 186 cfs and that would reduce the number of potential days of flow.
But the water meant for endangered fish near Grand Junction is also causing some grumbling in another 15-mile reach, the one on the Fryingpan River between Ruedi Reservoir and Basalt.
Higher flows
Since the flows out of Ruedi were increased by 50 cfs on Aug. 12 from about 250 cfs to about 300 cfs, the manager of Frying Pan Anglers in Basalt said he has been hearing unprompted complaints about the river being up.
“I even heard it twice today,” said Marty Joseph of Frying Pan Anglers, on Wednesday.
While Joseph said he and other local guides on the river would rather see the river at 240 cfs throughout September for their fly-fishing clients, he also said the “hatches are still good and the fishing is great at 298” cfs.
But there could also be other water released from Ruedi beside fish water and base release flows, especially if it gets hot and dry. More water could potentially be released to meet demands for “contract water” held in Ruedi or if a call comes up the river from Grand Valley irrigators with senior water rights.
In any event, local anglers frustrated by the higher flows in the Fryingpan might appreciate knowing that in addition to water stored in Ruedi, the Fish and Wildlife Service also uses water stored in Granby, Williams Fork, Green Mountain and Wolford reservoirs to help keep the Colorado River flowing at various targeted flows, depending on the season. And that the fish water is needed because of both upstream transmountain diversions and irrigation diversions just above the 15-mile reach.
For example on Aug. 31, at least 550 cfs of water from the Colorado River headwaters was flowing east through tunnels to the Front Range.
And 2,045 cfs was being diverted from the Colorado River above Palisade by various Grand Valley irrigators.
Meanwhile, flows in the 15-mile reach were left at 1,130 cfs on Aug. 31, below the target flow of 1,240 cfs, but still boosted by the fish water from Ruedi.
Editor’s note: Aspen Journalism and the Aspen Daily News are collaborating on coverage of rivers and water. The Daily News published this story on Friday, Sept. 2, 2016.