Aspinall Unit update: Estimated target of 6,800 cfs high flow regime in the Gunnison Gorge and Black Canyon

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Here’s the high-flow regime planned for the Black Canyon and Gunnison Gorge this week from email from Reclamation (Dan Crabtree):

Reclamation will be operating the Aspinall Unit to allow the one day Black Canyon water right peak target flow of 6,800 cfs to be met during the next two weeks. Releases from Crystal Reservoir will ramp up from the current release of 3,500 cfs beginning Friday, June 3rd. Crystal Reservoir should begin to spill sometime Saturday June 4th. While spilling, natural fluctuations will be seen in the river system making it difficult to predict and control downstream flows. However, below is a table showing estimated flows in the Black Canyon and Gunnison Gorge below the Gunnison Tunnel. These flows should reach a peak of about 6,800 cfs on June 8th and return to about 3,200 cfs around June 13th. During this operation, combined flows of the mainstem Gunnison, North Fork and other tributaries may result in flows of around 13,000 cfs in the Delta area. Again, this schedule is an estimate and may be modified due to changing hydrologic conditions in the Gunnison basin. Further updates will be conveyed as changes occur…

Date: Flow below Gunnison Tunnel (cfs)
June 3: 3,000
June 4: 3,500
June 5: 4,500
June 6: 5,500
June 7: 6,900
June 8: 6,900
June 9: 5,900
June 10: 5,000
June 11: 4,300
June 12: 3,750
June 13: 3,150

Here’s an article from a couple of years ago explaining the high flow regime, from Mark Jaffe writing for The Denver Post. From the article:

The stronger flow is intended to mimic natural spring runoff, removing sediment and algae and helping to break down riffles and whisk away vegetation encroaching on the riverbank, Dale said…

“This has been one of the longest, most complex water-right battles in Colorado,” said Drew Peternell, an attorney for the sportsmen’s group Trout Unlimited. To win that right, the concerns of hydropower agencies, ranchers and farmers — and downstream towns fearful of flooding — had to be addressed.

More Aspinall Unit coverage here and here.

Mesa State College: The Water Center at Mesa State is now in operation

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Say hello to the Water Center at Mesa State. Thanks to Hannah Holm for the link. From the website:

The Mission of the Water Center at Mesa State College is to perform and facilitate interdisciplinary and collaborative research, education, outreach, and dialogue to provide citizens, scholars, and policy makers with the information they need to address the water issues facing the region. The Water Center will foster communication and collaboration among the college, agencies, local governments, industry and non-profits with water expertise and stakeholder interest among the many water-relevant disciplines. The geographic focus of the Water Center will be the Colorado River and its tributaries in Western Colorado and the Upper Colorado Basin.

More Colorado River basin coverage here.

Garfield County: Septage disposal is a problem for county pumpers

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From the Glenwood Springs Post Independent (John Colson):

Garfield County and from Pitkin and Eagle counties and the tiny hamlet of Marble, which is in Gunnison County but located at the upper end of the Crystal River valley south of Carbondale. In recent months, Maynard continued, South Canyon has been reducing the amount of septage it will accept…

Garfield County normally operates three treatment ponds at the county landfill near Rifle, where trucks could regularly deliver material gathered from residential and commercial septic systems. But two of those treatment ponds were recently shut down at the state’s request, due to concerns that the ponds were leaking into the soils surrounding the county landfill site. The one pond still in operation has filled up and can no longer accommodate further deliveries of septage, according to Garfield County public works director Betsy Suerth. That means septic tank service companies must truck tons of the stuff to landfill locations as far away as Delta County or Denver, according to Warren and Maynard.

Trucking septage loads to distant facilities is a hassle and expensive, said Maynard. She said it can involve trip costs of up to $150 per hour that must be passed on to the customer. “That’s more than some of them will pay to have their septic pumped,” she noted. “That makes it very expensive to pump out a septic tank,” said Warren. “When some people get problems, they just pump it out themselves, onto a field or something.”[…]

He said unincorporated areas of Garfield County have some 5,000 septic systems in operation, as well as 20 or more drilling rigs with associated septic tanks and innumerable portable toilets in a variety of locations, all being regularly pumped out. Rada estimated that Pitkin County has as many as 3,000 septic systems, the waste from which comes to Garfield County facilities.

More wastewater coverage here.

Runoff news: Dust on snow events leave less mass than in 2010

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From The Denver Post (Jason Blevins):

Beyond the expected deluge, there is widespread worry about just how big the runoff could be. Lengthy stretches of hot temperatures could yield a tempest of whitewater that will swamp entire riverside regions. A healthy weather mix of cool and cloudy with warm and clear could stagger the surge, prolonging the season and keeping rivers roiling deep into July, August or even September. While no one knows what’s to come, at least one factor that has plagued Colorado’s runoff in recent years seems to not be playing as prominent a role this spring. For the last decade, windblown dust from the Colorado Plateau has painted Colorado’s peaks a reddish hue, absorbing sunshine and hastening snowmelt. This year is no different, with snow watchers counting nine significant dust events in Colorado. But unlike recent years, the density of the dust seems less this season…

But the lack of deeply darkened layers doesn’t necessarily exclude a deluge, warns Chris Landry, the executive director of Silverton’s Center for Snow and Avalanche Studies who has studied the impact of desert dust on Colorado’s snowpack since 2003. Dust layers merge as the snow settles and melts, creating incrementally darkening layers of snow that, once exposed to sunlight, accelerate the melt, Landry said. When warmth and sunshine reache that final layer, especially if it’s resting atop lots of water-laden snow, expect a deluge. Landry has recorded nine dust events across the state this spring but with “substantially less dust,” he said, especially in the northern and central ranges of the state. And “while every year is different,” Landry said, “there is an inevitability that at some point that final consolidated dust layer will come into play.”

From (Dann Cianca):

The Loma boat launch ramp was crowded on Memorial Day as rafters and kayakers hit the Colorado River. The flow of the river is quite high, however and those waiting to launch watched as large pieces of trees floated by in the rapid, silty water…The National Weather Service has issued a flood advisory for the stretch of river along the Utah/Colorado border as the river is at bankfull and could go higher in the next few days.

From (Jeffrey Wolf):

The National Weather Service is predicting that by Wednesday or Thursday, the runoff in north-central Colorado will begin in earnest. Its latest report indicates, “Drainages most susceptible to snowmelt flooding this spring include the Cache La Poudre, Big Thompson and Laramie Rivers in Larimer County; the North Platte, Illinois and Michigan Rivers in Jackson County; the Blue River in Summit County; the Colorado River in Grand County; and Clear Creek in Clear Creek County.”

From the Associated Press via The Columbus Republic:

Areas along the Green and Colorado rivers in eastern Utah are under a flood advisory. Forecasters say about two inches of rain have fallen since Friday. More than a foot of snow fell in higher elevations.

From the Fort Collins Coloradoan (Kevin Duggan):

A spike in temperatures forecast for later this week could launch what is expected to be a massive spring runoff on the Poudre River. The result could be flooding in areas with a history of problems during times of high water, including the McConnell Subdivision and County Road 5 near Timnath, said Erik Nilsson, emergency manager for Larimer County. Historically, runoff on the Poudre hits its peak around Father’s Day. This year, given that snowpack in the mountains is more than double of average for the time of year, the peak may come later, Nilsson said…

Flood stage at the mouth of Poudre Canyon is 7.5 feet or about 5,000 cubic feet per second, or cfs, according to the U.S. Geological Survey. Through Fort Collins, flood stage is 12 feet or 10,500 cfs. As of Monday afternoon, the river was running at 4.13 feet at the canyon mouth and about the same in Fort Collins.