Aspinall Unit operations update: Gunnison River through Black Canyon streamflow to increase to 1100 cfs

From email from Reclamation Erik Knight:

Releases from Crystal Dam will be increased from 600 cfs to 1100 cfs on Monday, November 16th. The purpose of this increase is to lower Blue Mesa Reservoir down towards the winter icing target. The current content of Blue Mesa Reservoir is 673,000 acre-feet which is 81% full.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for the remainder of the year.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are 600 cfs. After this release change Gunnison Tunnel diversions will still be at 0 cfs and flows in the Gunnison River through the Black Canyon should be around 1100 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Sunrise Black Canyon via Bob Berwyn
Sunrise Black Canyon via Bob Berwyn

#ColoradoRiver Basin: Parties looking to build on 2007 Shortage Sharing Agreement for Powell and Mead

Colorado River Basin, USBR May 2015
Colorado River Basin, USBR May 2015

From The Grand Junction Daily Sentinel (Dennis Webb):

nterim guidelines for managing both Lake Powell and Lake Mead and the Colorado River system still have more than a decade to go before they expire, but have been successful enough that parties are already looking to start talks about making them a little less interim.

The guidelines were finalized in 2007 and are scheduled to expire in 2026. While negotiations to extend them are scheduled to begin in 2020, they could start even sooner, Steve Wolff with the Wyoming State Engineer’s Office said Thursday at the Upper Colorado River Basin Water Forum, presented by Colorado Mesa University’s Ruth Powell Hutchins Water Center.

“They’re starting way in advance of when they actually expire,” he said.

Ted Kowalski, interstate section chief of the Colorado Water Conservation Board, credited former Interior Secretary Gale Norton, of Colorado, for helping provide direction for the agreement. He said it has resulted in a “historic relationship” between states in the Upper and Lower Colorado river basins. Beforehand, representatives of the two basins couldn’t agree on anything and meetings between them usually included talk about possible litigation, he said.

Now, he says, “I can’t stress enough how the 2007 guidelines are working in the context of collaboration.”

The two big reservoirs are the two most important storage facilities in the river basin, said Eric Kuhn, general manager of the Colorado River District, based in Glenwood Springs. The guidelines integrate operations of the two reservoirs, for the first time operating them as a system, and govern what level of water shortages the Interior secretary has to impose when there’s not enough water to fully supply the Lower Basin states of California, Nevada and Arizona.

Chuck Cullom with the Central Arizona Project, which diverts Colorado River water for use in that state, said the project is a junior water user vulnerable to shortages. It’s important to understand how the river system will operate in shortages, and the guidelines determine how much water will be sent downstream from Powell each year based on rigorous and “refereed” determinations, he said.

“There’s no shenanigans. Everyone knows how the system is going to operate from year to year regardless of politics or changes in administration, and that’s important for all of us,” he said.

Conservation and collaboration have been important components of the guidelines, with water entities across the river system being motivated to take voluntary steps to keep water in the reservoirs at levels that avoid shortages. Kowalski said an example is the investment by Lower Basin states of hundreds of thousands of dollars in cloud-seeding programs in Wyoming, Colorado and Utah to try to boost precipitation levels.

The Lower Basin states don’t get to claim any of the extra water that results.

“But rather it’s built on this idea that if we have more water in the system, we’re all going to benefit,” he said.

#ColoradoRiver Basin: Aspinall Unit operations update

From email from Reclamation (Erik Knight):

Releases from Crystal Dam will be decreased from 1300 cfs to 600 cfs on Friday, October 30th. This reduction coincides with the shutdown of the Gunnison Tunnel. River flows may fluctuate by up to 200 cfs during the day of the diversion shutdown, but will return to the current level afterwards. The current content of Blue Mesa Reservoir is 676,000 acre-feet which is 81% full.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for the remainder of the year.

Currently, diversions into the Gunnison Tunnel are around 700 cfs and flows in the Gunnison River through the Black Canyon are 600 cfs. After this release change Gunnison Tunnel diversions will be down to 0 cfs and flows in the Gunnison River through the Black Canyon should still be around 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

This scheduled release change is subject to changes in river flows and weather conditions. For questions or concerns regarding these operations contact Erik Knight at (970) 248-0629 or e-mail at

Dry August and September leaves Horsetooth at 61% of capacity

Horsetooth Reservoir
Horsetooth Reservoir

From the Fort Collins Coloradan (Jacy Marmaduke):

…consistently hot temperature and little rain put the big drain on in late summer, as farmers called for more irrigation water. The reservoir on Friday was 61 percent of capacity, which is 125 percent of the average for Oct. 16.

Northern Water spokesman Zach Allen said what all that means is the reservoir is in good shape heading out of the agricultural irrigation season.

High reservoir levels at the end of 2014 coupled with a wet spring meant farmers diverted less water from the reservoir during the spring and most of the summer, water resources manager Sarah Smith said. That allowed for an excellent boating season for most of the summer.

Irrigation reservoirs, like Horsetooth, generally fill up in spring with rain and snowmelt. As summer progresses, they are drawn down as farmers’ need for irrigation increases.

While Horsetooth is doing well, the Poudre River is flowing more slowly than usual for this time of year. On Friday at the mouth of the Poudre Canyon, the river was flowing 74.6 cubic feet per second. The average for this time of year is 92 cfs.

Slower flows are likely due to the dry weather and lack of rainfall during the last several months, Smith said.

Southeastern Water board meeting recap: Lake Pueblo sedimentation discussed

Pueblo dam releases
Pueblo dam releases

From The Pueblo Chieftain (Chris Woodka):

Lake Pueblo is slowly filling with sediment that has reduced its capacity to hold water by about 7 percent over the last 40 years.

The equivalent of 19 feet of dirt over a football field, or 19 acre-feet, is coating various parts of the bottom of the reservoir, a natural consequence for any lake fed by streams and rivers.

The capacity for conservation storage — accounts that can be emptied and refilled — is down to 245,800 acre-feet.

The Bureau of Reclamation made the determination to apply the new limits at the beginning of the water year on Oct. 1 based on data collected in 2012, said Roy Vaughan, manager of the Fryingpan- Arkansas Project. It’s the first detailed look at sedimentation since 1994, when Reclamation found deposits were less than expected because the Arkansas River maintained its current at the bottom of the lake.

At Thursday’s meeting of the Southeastern Colorado Water Conservancy District board, the impact on future storage was discussed.

“We’re looking at water for the next generation,” said Jim Broderick, executive director of the Southeastern district. “We’ve been in a wetter period for the last couple of years, and reservoir levels have been near the top.”

About 25,000 acre-feet — nearly the amount Pueblo Water pumps in a year — could spill next spring if weather conditions are normal through the winter months and water is used in the same fashion as in the past. Lake Pueblo water levels still are about 138 percent of average, even though some water has been released over the past three months.

“What are the solutions?” Broderick asked Vaughan.

“Enlargement or dredging,” Vaughan replied quickly. “It’s been a 7 percent reduction over (40) years. That’s not to say something could be put in place. But what are the costs and who’s willing to pay?”

A third option would be to time storage and releases among users of the dam.

Two of the options, enlargement and re-operations, were considered in the district’s Preferred Storage Options Plan, largely abandoned when it stalemated after a decade of contention among Arkansas Valley water users.

Re-operations have largely been addressed by long-term federal contracts that overlay the basic protocol for Pueblo Dam’s operation.

Physical enlargement of the dam likely would mean reopening negotiations.

Dredging has its own issue. For one thing, the sediment is broadly spread over the floor of the lake, and is not lying in a big chunk that could be scooped out. According to the Reclamation report, it’s not settling in the area immediately above the lowest outlet on the dam.

Dredging might also worsen water quality, adding costs for treatment.
There are other economic considerations.

“The Fry-Ark water will stay in place because it’s cheap,” Broderick said. “But can you get your water out if you bring it in from transmountain sources? How much is the water worth? If we lose storage, how do we replace that?”

Board member Vera Ortegon said water users have managed water in the past so it does not spill. Water does not actually shlosh out of the dam, but is released to keep levels low enough to contain potential floods from upstream.

“We have not spilled much, have we?” Ortegon asked.

“No,” Vaughan said. “But we use additional storage in wet years, and then it’s pulled down in a dry cycle. You have to figure out what to do in wet years, so enlargement still comes into play.”

More from the Chieftain:

Lake Pueblo

  • Lake Pueblo began storing water in January 1974 and released water the next year.
  • Its total crest is almost 2 miles long, with 23 concrete buttresses in the center of the earthen dam.
  • Its original capacity to store 265,000 acrefeet for conservation use has been reduced to 245,800 acrefeet
  • The 550foot spillway at an elevation of 4,898 feet is designed to carry 191,500 cubic feet per second when the reservoir is at maximum elevation, 4,919 feet. That has never happened.
  • There are five outlets on the dam, all with multilevel intakes: Bessemer Ditch (393 cfs), the north outlet works (1120 cfs), the spillway outlets (8,190 cfs), the fish hatchery (30 cfs) and the south outlet works (345 cfs). To reduce flooding downstream, releases to the river are usually kept below 6,000 cfs.
  • Flows below the dam are timed to match water coming into the reservoir, except when water is being released from accounts or stored by exchange or in the winter water program.
  • Sedimentation could be accelerated if erosion increases on tributaries above Lake Pueblo, including runoff from areas damaged by large wildfires (such as the Royal Gorge Fire in 2013) or prolonged rain (such as road washouts in Fremont County earlier this year).
  • Scholars want science-based review of Colorado River study — The Deseret News

    From The Deseret News (Amy Joi O’Donoghue):

    The scholars want the bureau’s 2012 Colorado River Basin’s Supply and Demand Study to get an analysis by the National Academy of Sciences that specifically probes key areas they assert aren’t getting adequate attention.

    In a letter sent Tuesday to Interior Secretary Sally Jewell, the scholars cite lack of information regarding groundwater depletion, flood management, water demand forecasts, ecology, water quality and climate change.

    “If ever there was a time to undertake the first basinwide independent review of this vital natural resource, that time is now,” said John Weisheit, conservation director of Living Rivers and Colorado Riverkeeper. “Decisions should be based on the best available information and the National Academy is well positioned to ensure that.”

    The letter’s signatories include six faculty members from the University of Utah, among them Pat Shea and Dan McCool, who have argued for less diversions on the river and fewer water development projects.

    The bureau’s supply and demand study, initiated in 2010 and released at the end of 2012, addressed both current and future supply and demand imbalances on the river in light of growing populations, increasing urbanization and potential climate shifts…

    More than 150 study proposals were submitted to counter that shortfall, and the bureau is in the midst of another phase of implementing strategies that embrace environmental considerations, agricultural use, and municipal and industrial supplies.

    The letter indicates that as this phase moves forward, there are key concerns that need to be addressed.

    “Clearly (the Department of Interior) should seek the best available science for the management of this critical natural resource while taking a comprehensive look at the processes by which this important information will be integrated into Colorado River management.”

    As an example, the signatories to the letter say they are fearful there are supply options on the table that fail to adequately consider growing conservation trends throughout the basin states. The letter stressed the need to more fully understand stream flow forecasts in light of a changing climate and the vulnerability of the Colorado River system as a whole.

    “The National Academy of Sciences, through its National Research Council, has assisted the (Department of Interior) in the past on several Colorado River management issues,” the letter stated. “As scientists, we appreciate the peer review methods of the (National Academy of Sciences).”