
The roar was put back in the upper Roaring Fork River this week as the Twin Lake Reservoir and Canal Co. curtailed its diversions near the top of Independence Pass and let more water flow in the river through Aspen and down to the Colorado River.
The water returned to the river first makes its presence felt in terms of volume, as the Roaring Fork River above Difficult Creek east of Aspen climbed from about 200 cfs Tuesday to about 600 cfs by Thursday morning, swelling the slow-moving section of river through North Star to the upper limit of its banks.
The higher flows in the river as a result of Wednesday’s curtailments had not caused any problems in the valley as of midday Thursday, Pitkin County emergency manger Valerie MacDonald said.
“We still urge caution for people recreating in and around the river,” MacDonald said. “While many in the local community may appreciate the restoration of the natural flows in the river, the swift current, the cold temperature of the water and the now-slippery banks and rocks can catch visitors unaware.”
Placid, then pulsing
The Roaring Fork River, in the Cascades, on Independence Pass, at midday on Wednesday, June 14, 2017. The Twin Lakes-Independence Pass Tunnel was diverting about 600 cfs when this was taken.
The Roaring Fork River in the Cascades on Independence Pass at midday on Thursday, June 15, 2017. The Twin Lakes-Independence Pass Tunnel, which normally diverts around 600 cfs, was closed when this was taken.
This is the third consecutive year the company curtailed its transmountain diversions from Lost Man Creek, Lincoln Creek, and the Roaring Fork due to legal and physical constraints.
But prior to 2015, closing what’s officially called Tunnel No. 1 of the Independence Pass Transmountain Diversion System has been a rare occurrence.
It is not clear how long it will be before Twin Lakes Co. starts diverting again, lowering flows in the Roaring Fork.
“Once flows in the Arkansas [River] start to drop, which they will eventually, that will create more demand for Twin Lakes water and then we’ll start taking some more,” Twin Lakes Co. President Kevin Lusk said. “But in terms of how much and when, it’s really up to the weather and the different shareholders, in how they are managing their supplies.”
Lusk is aware that curtailing diversions may increase the chance of flooding in the Roaring Fork River basin.
“There’s always concerns about flooding and managing flows, but there is only so much that we are legally able to do,” he said.
Last year, the tunnel was closed from June 14 to June 28.



East, then west


At dawn Wednesday, 598 cfs of water coursed out of the Twin Lakes Tunnel on the eastern slope, as usual, after having entered the tunnel at Grizzly Reservoir on Lincoln Creek on the west slope. (Technically, it is Tunnel No. 1 of the Independence Pass Transmountain Diversion System.)
But by noon, there was just 5 cfs flowing through the tunnel.

Correspondingly, the flow in Lincoln Creek below Grizzly Reservoir went from a trickle of 2.8 cfs at the start of Wednesday, and ended the day at 319 cfs, which is enough water to make it hard to wade across.
And the rest of the water was being released down Lost Man Creek, the main stem of the Roaring Fork, and three creeks that run into lower Lincoln Creek.
At 10:30 a.m. Wednesday, the tunnel under Independence Pass was fully closed and water was instead collected and slowly released out of Grizzly Reservoir, with all of the water fully turned out by 9:30 p.m.



Lincoln, Roaring
Lincoln Creek and the Roaring Fork come together just below Lincoln Gulch Campground and just above the Cascades at the Grottos area on Independence Pass.
At 8:25 p.m. Wednesday, as the front edge of the flow of released water in Lincoln Creek reached the confluence with the Fork, the last stretch of Lincoln Creek quickly went from walkable to swimmable.
The rising water took down a pile of rocks placed by passersby in what, the day before, had been a placid little stream. Now Lincoln Creek was a cold rushing river again, intent on joining the Roaring Fork to head together to the Gulf of California.
A short clip of Lincoln Creek on June 14, 2017, just above the confluence with the Roaring Fork River.




The same location as above, a day later, on June 15, 2017, but initially looking downstream, not up. Note the cloudy, deep water. The little rock piles (see below) would be in the frame, but they are now submerged. And one would think twice before trying to wade across, given the volume and depth of the water.
Also, please see a 3-minute video of Lincoln Creek rising as the front edge of the flow reaches the rock piles at its confluence with the Fork, at 8:25 p.m. Wednesday, June 14, 2017: https://youtu.be/YkchIo3mZU4.
Cascades cascading

Around the corner from the confluence of the Lincoln Creek and the Fork are the Cascades, which went from mild on Wednesday afternoon to wild by Thursday afternoon when whitewater poured over the rocks in a renewed frenzy of foam and spray.
In addition to adding volume to the river and creeks, the return of natural flows brings the Roaring Fork headwaters back to life, adding an urgency and vibrancy to the flow that’s been missing since the Twin Lakes diversion system was built in the 1930s.
The system originally sent water to sugar beet fields in the Arkansas River basin, but most of the water today goes to Colorado Springs, Pueblo, Pueblo West, and Aurora.
Colorado Springs owns 55 percent of the shares in Twin Lakes Co., Pueblo 23 percent, Pueblo West 12 percent, and Aurora 5 percent. There are also other minority shareholders, holding 5 percent of the shares, still using the water from the system for agriculture.
In the 10 years from 2007 through 2016, Twin Lakes Co. diverted a total of 485,762 acre-feet of water from the upper Roaring Fork River basin through its diversion system, with 2011 the highest year since 2007 with 67,463 acre-feet diverted and 2015 the lowest year since 2007 with 18,374 acre-feet diverted.
The water rights held by Twin Lakes Co. have limitations that can cause it to stop diverting, including a junior diversion right on the Colorado Canal, which takes water from the Arkansas River near Ordway, and the amount of water in Twin Lakes Reservoir, which is owned and operated by the Bureau of Reclamation.
In short, when flows in the lower Arkansas River are relatively high and the Colorado Canal can use “native water” from the east slope, and the Twin Lakes Reservoir is full, the Twin Lakes Co. cannot divert water under Independence Pass.
The water rights for the diversion system have an appropriation date in 1930 and an adjudicated decree from 1936.
‘Compare and contrast’
A few sets of photos comparing flows on June 14 and June 15, 2017.








Links to gauges
Twin Lakes Tunnel
Tunnel No. 1 of the Independence Pass Transmountain Diversion System, which is owned by the Twin Lakes Reservoir and Canal Co.

Lincoln Creek below Grizzly Reservoir

Roaring Fork River above Difficult Creek

Roaring Fork River above Salvation Ditch
Located at Stillwater Drive. Good gauge for flows in Stillwater/Northstar section of Fork.

Roaring Fork River below Salvation Ditch, at Mill Street
Subtracting this gauge from the gauge above approximates Salvation Ditch flow

Roaring Fork River below Maroon Creek
This gauge, which was used to judge Slaughterhouse and Toothache, is now inactive.


Fryingpan River below Ruedi
Subtract this gauge from Emma gauge to determine flows in Basalt kayak park on the Fork.


Colorado Canal
This is the Avondale gauge on the Arkansas River. When it’s below 3,000, the Colorado Canal is likely to be out of priority, which means Twin Lakes Reservoir and Canal Co. can divert again through the tunnel under Independence Pass, if there is room in Twin Lakes Reservoir to first accept the water.

Editor’s note: Aspen Journalism is collaborating on coverage of rivers and water with The Aspen Times, the Glenwood Springs Post Independent, the Vail Daily, and the Summit Daily News. The Times published a version of this story on Friday, June 16, 2017, as did the Vail Daily.