Senior calls on the river, fish water in the Pan

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Brent Gardner-Smith/Aspen Journalism

The penstocks of the Shoshone hydropower plant in Glenwood Canyon controls a key senior water right on the Colorado River.

Very low flows in the upper Colorado River system are now expected to trigger calls from senior water rights tied to the Shoshone hydropower plant and irrigators in the Grand Valley. And, starting Friday, more water is to be released from Ruedi Reservoir into the lower Fryingpan River to bolster downstream flows.

The Shoshone plant has two water rights: a very senior 1905 right for 1,250 cubic feet per second and a less-senior right for 158 cfs with a 1940 priority date. A call for the 1940 Shoshone right took effect today, meaning those upstream from the Shoshone hydropower plant in Glenwood Canyon who hold junior rights must stop diverting.

On Sunday, another, larger call is expected to happen downstream on the Colorado — the Cameo call. The Cameo call is made up of the water rights of agriculture diverters near Palisade, including the Grand Valley Water Users Association and the Orchard Mesa Irrigation District.

One of two large irrigation canals that run westward from Palisade west through the Grand Valley, the Grand Valley Irrigation Canal, which makes up part of the Cameo call, diverts water near the top of the 15-mile reach. Water managers are taking steps to release water from upstream reservoirs to counter the effect of the diversions from the river in order to protect endangered fish species.

Cameo call

The Cameo call, which is the second-most senior water right on the Colorado River, calls about 2,200 cfs down through the river system, but the diversion structures tied to the call also have the potential to nearly dry up the Colorado River in a 15-mile reach between the Palisade area and the confluence of the Gunnison River in Grand Junction. This 15-mile reach is critical habitat for endangered fish, including the Humpback Chub.

To help offset the effects of the big diversion structures that send water to the Grand Valley and the effects of other diversions upstream on the river system, officials with the Upper Colorado River Endangered Fish Recovery Program have set a low-flow target of 810 cfs this year.

The Colorado River flowing at about 1,100 cubic feet per second on April 12, 2018, not far above its confluence with the Gunnison River, in Grand Junction. The 15 miles of river upstream of this location is known as “the 15-mile reach,” where federal officials are working to maintain flows between 400 and 810 cfs in cooperation with regional water managers.

‘Brutal year’

And after meeting with other regional water managers on Wednesday, the officials now plan to release on Friday 50 cfs of water that has been earmarked specifically for endangered fish from Ruedi Reservoir. Another 100 cfs will be added to the bolstered flows on Monday, bringing releases to about 260 cfs in the river below Ruedi Reservoir.

While a Cameo call is not unusual and often happens in late summer, according to Don Meyer, senior water resources engineer with the Colorado River District.

 “It’s a brutal year,” Meyer said. “I think it’s going to be a dire situation for everybody, but especially the fish down there.”

Meyer said he expects the senior Shoshone call to come on soon, which could delay the Cameo call. But with the warm, dry weather forecast, he said the Cameo call will happen soon.

There are several “colors”, or pools or layers of water in Ruedi Reservoir, which holds about 100,000 acre-feet of water. One is “fish water,” and this year there is 16,412 acre-feet of water expected to be available for federal officials to use to bolster flows in the Colorado River near Grand Junction.

Fish water

This year also is the second earliest that “fish water” has been released from Ruedi Reservoir since the endangered fish program was established in 1988. During the most recent drought years, 2002 and 2012, fish water was released June 24 and July 3, respectively.

Federal officials expect to be able to release 16,412.5 acre-feet of fish water from Ruedi Reservoir this year, including from a 5,000 acre-foot pool, a 5,412 acre-foot-pool and 6,000 acre-feet of water owned by Ute Water Conservancy District in the reservoir, which is to be leased for the endangered-fish program.

In all, the fish program has a total of 28,000 acre-feet of water it can use from various reservoirs in the upper Colorado River system, including Ruedi, Granby and Wolford reservoirs.

Brent Gardner-Smith/Aspen Journalism

The east end of the Twin Lakes Tunnel on June 6, 2016. The four-mile long tunnel, which brings water from Grizzly Reservoir to Lake Creek, Twin Lakes Reservoir, and on to Front Range cities and fields, will stop diverting when the Cameo call goes into effect.

Transmountain diversion

The Cameo call also will put more water into the Roaring Fork River by “calling out” the transmountain diversion through the Twin Lakes tunnel under Independence Pass. The Twin Lakes Reservoir and Canal Company can move 625 cfs of water out of the Roaring Fork Basin to the Arkansas Basin, where it is used for East Slope municipal and irrigation purposes.

The tunnel is currently diverting around 50 cfs, but that will come to a halt when the Cameo call goes into effect.

“In one respect it’s a windfall for the Roaring Fork,” said Kevin Lusk, president of Twin Lakes Reservoir and Canal Co. “It’s not good for our customers, but that’s the law. It’s just part of owning a water right on a river in Colorado. This is one of those dry years, so we are not surprised to see the Cameo call come on.”

Source: Bureau of Reclamation

A map showing Ruedi Reservoir, the Fryingpan River, and the 15-mile reach on the Colorado River near Grand Junction.

See related stories:

Low runoff in Colorado River could be hard on endangered fish

Who owns the water in Ruedi Reservoir?

River gages:

Flows in the 15-mile reach below Palisade

Flows in Government Highland Canal

Flows in Grand Valley Irrigation Canal

Flows in Orchard Mesa Canal System

Flows at Shoshone

Flows in Roaring Fork at Glenwood

Flows in Roaring Fork through Aspen

Flows in Independence Pass-Twin Lakes diversion tunnel

Flows in the Fryingpan below Ruedi

Editor’s note: Aspen Journalism is covering rivers and water in collaboration with The Aspen Times and Glenwood Springs Post Independent. The Post Independent and the Times published this story in their print editions on Thursday, June 28, 2018.

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