Runoff/snowpack news: Colorado is mostly melted-out #ColoradoRiver

From the Associated Press via the Casper Star Tribune:

Strong spring runoff from heavy mountain snow is filling reservoirs in the upper reaches of the Colorado River drainage in western Wyoming.

Rangelands in western Wyoming are unusually dry, but the Green River is flowing high and fast.

Hydrologist Jim Fahey with the National Oceanic and Atmospheric Administration predicted more healthy runoff in the weeks ahead thanks to lingering mountain snow.

Fahey said Fontenelle Reservoir is 67 percent full and could get to 90 percent full by the end of this summer. Flaming Gorge Reservoir is 86 percent full, up from 75 percent in January.

Fahey said flows in the Green River could boost low water levels in Lake Powell and Lake Mead, but not by more than 1 or 2 percent.

From email from Reclamation (Erik Knight):

Right now Morrow Point dam is currently releasing ~6,500 cfs. This combined with Cimarron River flows has continued the spill at Crystal with flows in the Gunnison River through the Black Canyon fluctuating around 6,500 cfs. Flows in the Gunnison River at the Whitewater gage are still above the half bankfull target of 8,070 cfs. However, flows at Whitewater have been declining over the past few days coinciding with the drop in flows from the North Fork of the Gunnison River.

Attempts to meet the half bankfull flow target of 8,070 cfs will continue with releases from the Aspinall Unit combined with tributary flow. Flows in the North Fork of the Gunnison River and other tributaries are quickly declining towards summertime baseflow levels.

From email from Reclamation (Kara Lamb):

I was out of the office for a few days and in that time, we saw inflows to Green Mountain Reservoir drop off a little bit. We stopped sending water over the spillway and reduced releases.

Two more changes were made today at Green Mountain Dam, further curtailing releases. As a result, we are now releasing 1000 cfs to the Lower Blue River.

From the Estes Park Trail Gazette (David Persons):

It appears that the spring runoff along the Big Thompson River system has peaked and is subject to only brief surges, like the one last weekend, as the remaining snowpack in the mountains melts off…

Kara Lamb, the public information officer for the U.S. Bureau of Reclamation’s Eastern Colorado Office in Loveland, said that the way the spring runoff has occurred this year has been about as good as hoped for.

“Yeah, I would say we have been pleased so far,” Lamb said Monday afternoon. “Everyone had some apprehension going into this with the snowpack being so high and the river having rechanneled because of the flood…

Currently, Lamb said the bureau is continuing to divert between 350-550 cfs in the Olympus Tunnel in addition to what is being released at Olympus Dam. That water had been going to Horsetooth Reservoir. However, Horsetooth is about six inches from capacity so most of that water is now being sent to Carter Lake with the rest (about 100 cfs) going back into the Big Thompson River at the mouth of the canyon.

Lamb said the water going into Carter Lake raised the lake’s level by about a foot since last Friday.

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