Big snowpack didn’t translate to big water diversion from Upper Roaring Fork River this year
The Aspen Times
The massive plumbing system that taps the headwaters of the Roaring Fork River has diverted less water than usual to Colorado’s East Slope this year despite the beefy snowpack.
The Independence Pass Transmountain Diversion System has sent about 35,000 acre-feet to the east side of the Continental Divide this year. The annual average is about 48,000 acre-feet and the maximum capacity is “just shy of 68,000 acre-feet,” according to Kevin Lusk, president of the board of directors of the Twins Lakes Reservoir and Canal Co. and a senior engineer with Colorado Springs Utilities. The canal company operates the diversion system.
“We’re not likely to get to average this year,” Lusk said. “Currently our company isn’t directing any water to the East Slope. Our water right has been satisfied.”
Lusk was one of the featured speakers Friday at a tour of the diversion system organized by Basalt-based Roaring Fork Conservancy. Roughly 30 people attended the field trip, ranging from city of Aspen officials to curious residents of the Roaring Fork Valley. Attendees said they wanted to learn about the diversion system and see the tunnel beneath the Continental Divide for themselves. The 4-mile tunnel runs from near Grizzly Reservoir up Lincoln Gulch on the Aspen side of the Divide and sends water to Lake Creek on the Twin Lakes side of the Divide. The water is stored in Twin Lakes for use by shareholders in Twins Lakes Reservoir and Canal Co.
Lusk said Colorado Springs owns about 55% of the shares in the reservoir and canal company.
“This is our bread-and-butter system,” he said.
The city of Pueblo owns another 25 percent of the shares, while Aurora possesses 5%.
Lusk and Christina Medved, director of community outreach for Roaring Fork Conservancy, started the tour at Lost Man Reservoir, which captures runoff from the surrounding mountains north of Highway 82. A canal and the original creek bed carry the water to the Roaring Fork River, which is dammed near Lost Man Campground on the south side of Highway 82. Few locals or tourists are aware the dam exists less than one-half mile from the busy road.
A tunnel on the south end of the dam sends the water below towering Green Mountain and into Lincoln Gulch. A canal feeds the water into Grizzly Reservoir, then another tunnel sends diversions east, beneath the Continental Divide and to Lake Creek.
The participants in Friday’s tour got to observe all the workings. It is the fifth largest transmountain diversion system in Colorado, Medved said. It collects water from a 45-square-mile area that includes Lincoln Creek and its subsidiaries — Brooklyn, New York, Tabor and Grizzly creeks — as well as Lost Man Creek and the Upper Roaring Fork River.
Lusk said the initial dams, tunnels and canals of the system were built in the mid-1930s, initially to irrigate agricultural lands. As specific markets such as the Colorado sugar beet industry failed due to international economic pressures, the water became available and was snatched by municipalities such as Colorado Springs and Pueblo. It is rare for shares to become available for sale now, Lusk said.
A separate water diversion system taps the Upper Fryingpan River basin. That is the third largest system in Colorado, according to Medved. The U.S. Bureau of Reclamation operates that system, known as the Fryingpan-Arkansas Project. About 81,016 acre-feet of water had been diverted east by that system as of July 18. The forecast is for 84,000 acre-feet.
In a year when the snowpack was so high and lingered so long into summer, it is counter-intuitive that the water diverted from the Upper Roaring Fork River basin was below average, Lusk acknowledged.
However, the mountains on the east side of the Continental Divide also had a massive snowpack that produced a bountiful runoff. For legal reasons in Colorado’s complex water law and because of lack of storage in reservoirs, not as much water had to be diverted from the Upper Roaring Fork River basin this year, Lusk said.
Diversions ended right around July 4, he said. All the water now reaching the dam on the Roaring Fork River is being passed through, and that is creating a streamflow much higher than usual for this time of year.
The prolific avalanche cycle that altered landscapes throughout the Elk Mountains surrounding Aspen during the first week of March also affected the water diversion system. Several slides hit Lincoln Creek Valley. The reservoir and canal company years ago added snowsheds over portions of its canal between Green Mountain and Grizzly Reservoir, Lusk said. However, this winter’s avalanches were wider than in year’s past and wiped out trees that formerly weren’t in the slide paths. The paths were wider than the snowsheds.
It is suspected that debris got into the diversion system because it wasn’t capable of hauling as much water as usual, Lusk said. Debris will be cleared from screens later in the summer as water levels are drawn down.
The Roaring Fork Conservancy has been leading tours of the diversion system for roughly 17 years and attracts new rounds of curious observers. The nonprofit organization places a big emphasis on getting people out to see issues affecting the watershed, Medved said.
“Last year we taught over 6,600 students” of all ages, she said.
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