Cooperative releases from headwaters reservoirs will help sustain environmental and recreational values
By Bob Berwyn
SUMMIT COUNTY — With some of the lowest stream flows on record for this time of year, Colorado water managers are wrangling every last drop and trying to make them all count.
Upstream storage and diversions have exacerbated the low flows resulting from a meager snowpack and early runoff. As a result, water temperatures in parts of the Colorado River recently have already reached temperatures close to 60 degrees, which is borderline dangerous for trout. Those temperature readings were measured at a gage in the Pumphouse area, according to Jim Pokrandt, communications specialist with the Colorado River District.
Average Colorado River flows through Glenwood Canyon this time of year are about 6,000 cfs, but this year, the river has been flowing at less than 20 percent of that, at about 1,100 cfs.
Looking to raise stream flows, the Colorado River District, Denver Water and the Bureau of Reclamation are cooperating under the Shoshone outage protocol, which helps sustain flows along the Colorado River mainstem with water from Wolford Mountain Reservoir, Williams Fork Reservoir and Green Mountain Reservoir — even when Xcel’s Shoshone power plant isn’t exercising a senior water right that historically keeps at least some water in the river during dry seasons and years.
“This makes a real difference in the river,” said Colorado River District general manager Eric Kuhn. “Since we started, you can see … that the temperature of the water has come down 4 degrees.
Releases from the three reservoirs of about 450 cfs should help sustain flows through Glenwood Canyon at about 1,100 cfs at least through this weekend and early next week. The 1.100 cfs flow rate is a benchmark for commercial rafting outfitters on the river, and the releases will also help farmers in the Grand Valley, Pokrandt said.
“This is exactly why we all came together to sign the … agreement,” said Denver Water CEO and general manager Jim Lochhead.
When Shoshone is using its water to generate power, it helps sustain summer flows between the headwaters of the Colorado down to the Grand Junction area. But right now, the Shoshone power plant is only operating at about half its capacity, requiring about 700 cfs. Xcel Energy is doing maintenance work that could last through the summer, putting even more of a squeeze on flows.
“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,” said Grand County manager Lurline Underbrink Curran.