Shoshone protocol boosts Colorado River flows
Aspen, CO Colorado
GLENWOOD SPRINGS – A formal agreement governing the Colorado River, hammered out over the past six years among 43 Western Slope and Front Range entities, is now paying off for fish, anglers, boaters and cities that divert river water for municipal use.
A section of the Colorado River Cooperative Agreement called the Shoshone Outage Protocol is ensuring that flows through Glenwood Canyon and farther upstream will remain at or close to the normal 1,250 cubic feet per second (cfs) level, according to Jim Pokrandt, spokesman for the Colorado River District.
That flow level keeps the water cool enough for fish, high enough for rafting, and clean enough for towns that use river water, such as Silt and Rifle.
The protocol came into play last week when river managers and wildlife officials could see that drought conditions were pushing river flows well below the 1,250 cfs level normally maintained through Glenwood Canyon.
At the same time, Xcel Energy has its Shoshone hydroelectric power plant in Glenwood Canyon operating at half capacity while crews do repair and maintenance work on the plant’s overflow pipes.
When the plant is running at full capacity, its senior water right, known as the “Shoshone call,” ensures that flows stay at or above 1,250 cfs. But with plant operations curtailed and the water right not being exercised, Colorado River flows fell below 1,000 cfs from Monday, June 11, to Wednesday, June 13.
At that level, river companies were having a tough time getting passenger rafts down the popular Shoshone stretch, between the power plant and Grizzly Creek, Pokrandt said. In addition, temperatures in the river were rising, which puts a strain on coldwater-loving trout and the river insects they feed on.
Last Wednesday, key players in the Shoshone protocol got on a conference call to discuss the situation, and agreed to make extra releases of about 450 cfs of water from three reservoirs.
Contributing to the flows are the Colorado River District from its Wolford Mountain Reservoir, Denver Water from its Williams Fork Reservoir, and the U.S. Bureau of Reclamation from its Green Mountain Reservoir, all near Kremmling.
By 10 a.m. on Friday, June 15, flows hit the normal 1,250 cfs level, and hovered between 1,250 and 1,300 through the weekend. By 4 p.m. Monday, flows had climbed over 1,400 cfs.
“The bottom line is to mimic the Shoshone call for the benefit of fish, recreationists and cities that divert water from the river, such as Rifle and Silt,” Pokrandt said.
“This makes a real difference in the river,” said Eric Kuhn, general manager of the Colorado River District. “Since we started [boosting flows], you can see by the gauge that the temperature of the water has come down 4 degrees Fahrenheit.”
The Shoshone call will remain inactive while power plant repairs continue, said Mark Stutz, Xcel spokesman. “The goal is to get done before winter, so it will be into the fall before we do the full call again,” Stutz said.
Pokrandt said the river flow situation will be assessed in a conference call on a weekly basis for the time being.
“Every Wednesday the reservoir operators, irrigators, fish biologists and Denver Water will get on the phone and see what the river and the weather look like,” Pokrandt said. Based on forecasts, the group will decide how much extra water to release under the Shoshone protocol.
“There is a limit to how much water is in these reservoirs,” Pokrandt noted, but for now the releases can be managed.
By mid-July, river managers expect that flows in the Colorado River at Palisade will fall low enough that Grand Valley irrigators will exercise the Cameo call. That’s another very senior water right that will require water users upstream with younger water rights to curtail or shut down their diversions from the river.
But for now, the agreement between Western Slope and Front Range water users under the Shoshone protocol is serving as a means to maintain flows along the Colorado River from Parshall in Grand County, through Glenwood Canyon and all the way to Palisade.
“This is exactly why we all came together to sign the Colorado River Cooperative Agreement – to provide benefit to the Colorado River. Denver Water is proud to be part of an effort that fulfills our goal to operate our system in a way that benefits the environment,” said Jim Lochhead, manager of Denver Water.
Grand County manager Lurline Underbrink Curran said, “This is a good example of how the Colorado River Cooperative Agreement can work when everybody is pitching in to help the river in a time of need.”
“This is a great level right now,” said Geoffrey Olson, co-owner of Blue Sky Adventures, a rafting outfitter in Glenwood Springs, on Monday. “The higher flows makes for a more fun ride through the canyon. We’d like the water to keep coming.”
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