Aspinall Unit operations update: Gunnison Tunnel diversions = 950 cfs, Gunnison River through the Black Canyon = 2550 cfs

Gunnison Tunnel via the National Park Service

From email from Reclamation (Ryan Christianson):

Releases from the Aspinall Unit were increased by 500 cfs beginning on Friday, July 26th and are scheduled to continue at that rate into the near future in order to prevent Blue Mesa Reservoir from overfilling. At the current inflow and release rate it is projected that Blue Mesa Reservoir would begin spilling, as the reservoir is now full. The current forecast for the April-July runoff volume for Blue Mesa Reservoir is 1,075,000 AF of inflow, which is 159% of average. Flows in the lower Gunnison River are currently above the baseflow target of 1500 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 1500 cfs for July and August.

Currently, diversions into the Gunnison Tunnel are 950 cfs and flows in the Gunnison River through the Black Canyon are around 2550 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

For a while in 1983, sheets of plywood were all that kept the mighty Glen Canyon Dam from overflowing — #Arizona Central

1983 – Color photo of Glen Canyon Dam spillway failure from cavitation, via

Here’s an in-depth report about the time the left spillway failed at Glen Canyon Dam from John D’Anna writing for The Arizona Republic. It’s quite a tale. Click through and read the whole thing, here’s a excerpt:

…water in Lake Powell would come within inches of topping the dam’s massive spillway gates as engineers frantically tried everything they could think of, rigging 4-by-8 sheets of plywood to extend the top of the gates and releasing more than half a million gallons per second into the Colorado River.

Before it was over, the force of the water releases would gouge house-size holes in the dam’s crippled concrete spillways. The white water would tinge red from the bedrock sandstone, and ominous rumbling sounds would be heard as boulders the size of cars belched from one of the spillways into the river.

The more water the engineers released, the more damage they did. But they had no choice.

“We were sitting on a pretty good catastrophe waiting to happen,” said Art Grosch, an electrician who worked at the dam and ran electrical cable into the mangled spillways.

“That lake (Powell) is 190 miles long and has something like 2,300 miles of shoreline,” he said. “And it was rising a foot a day.”


“Even if Lake Powell and Lake Mead remain low, megaflood risk persists and is likely to be increasing. Precipitation intensity, and the amount of precipitation falling in the most intense events, are increasing globally and across the United States, in large part because sea surface temperatures and atmospheric water vapor content are both rising, increasing the odds of more extreme precipitation events. These trends will continue as long as emissions of greenhouse gases to the atmosphere continue.”

Such a flood would be a longshot, what’s called a “black swan” event — something so incredibly rare as to be almost unimaginable. But the thing about a black swan is that you never see one until you see one, and in the late spring of 1983, the engineers at the U.S. Bureau of Reclamation were about to get a close-up look…

The 1982-83 El Niño was the strongest ever recorded at the time. The tales of its fury were recounted in newspaper headlines of the day — and later in books and scientific journals — as it unleashed disaster on virtually every continent, from searing droughts in Australia, Africa and south Asia, to violent floods in South America…

In a normal spring, the last major snowfall in the Rockies occurs around the end of March. As temperatures rise in the lower elevations, the snowpack melts slowly and creates a steady stream of runoff as temperatures rise into the higher elevations.

But there was nothing normal about the spring of 1983.

The late-winter snowfall of January and February was actually below normal, but in early March it accelerated and didn’t quit until May. And then, instead of increasing gradually, temperatures skyrocketed.

Instead of a slow, steady flow down from the mountains, the runoff gushed…

In the Rockies, every tributary of the Colorado River was running high and fast, and the Colorado itself was running at 100,000 cubic feet per second — enough water to cover the entire 517 square miles of Phoenix in 6 inches of water in less than a day.

And all that water was barreling into Lake Powell toward a choke point only a quarter of a mile wide. The only thing in its way was Glen Canyon Dam, which had only been completed 20 years before and had only been filled close to capacity once…

Gamble and his team were already releasing the maximum amount of water possible, about 40,000 cfs, through the eight massive turbines in the dam’s power plant. But as more and more water gushed into Lake Powell, Gamble knew he would have to begin releasing water through the dam’s two spillways, two massive tunnels bored into the sandstone on either side of the dam and running parallel to the river.

The spillways are 41 feet in diameter — picture the height of a Boeing 737 from the runway to the tip of the tail — and extend more than half a mile, beginning about 600 feet upstream of the dam and emptying out a few hundred feet on the downstream side.

Each tunnel is lined with concrete 3 feet thick and is controlled by colossal steel gates at the top — 52 feet tall and weighing 350,000 pounds — that control how much water is released. At the bottom of each is a “flip bucket,” a sort of 40-foot ski jump that sends the water into the air before it hits the river, dissipating its energy and controlling erosion.

The first third of each spillway tunnel drops more than 500 feet in elevation from lake level at a 55-degree angle beforeintersecting with horizontal tunnels that were originally drilled to divert water around the dam while it was being built.

The upstream portions of the diversion tunnels, which connected directly with the reservoir, were sealed with giant concrete plugs more than 150 feet long. Using the original diversion tunnels allowed the bureau to save time and millions of dollars by not having to drill thousands of more feet and line the new tunnels with concrete.

When the spillways are wide open, they are capable of releasing 276,000 cubic feet of water per second, more than 2 million gallons a second, from the reservoir. That number was based on detailed studies of peak flows down the Colorado through history, both the 100 years of recorded history by man and the eons of geologic history recorded in the strata of the canyon walls.

According to a design report from 1961, the 276,000 cfs number was 1.7 times the highest flow ever recorded on the river. In other words, the spillways were built to handle 70 percent more water than had ever been seen before on the Colorado.

It was little wonder then that Tom Gamble’s faith in his dam was unshakable…

On June 2, as the water surged toward the dam, it was just inches below the spillway gates.

Engineers opened the left gate and began releasing 10,000 cfs, enough to fill 450 backyard swimming pools every minute, but still only a fraction of capacity. Three days later, they doubled the flow to 20,000 cfs and planned to open the gates even more.

But early the next morning, on June 6, engineers began to hear strange rumbling noises from somewhere deep in the dam works…

As the sun came up, Gamble stood on a platform above the spillway, which for two days had been sending an elegant arc of white water into the river below.

But in the early morning light, Gamble could see large chunks of something — probably rocks or chunks of concrete the size of office chairs — being ejected into the river. And the white water had taken on a reddish tint, a hint that the spillway’s 3-foot concrete lining had somehow been breached and the native red sandstone that gave the Colorado its name was washing into the river.

Update: Post corrected to include the link to my Coyote Gulch post.

Here’s a Coyote Gulch post from a while back with video that tells the story about the spillway failures in 1983. I also include Seldom Seen Smith’s prayer from the, “Monkey Wrench Gang.”

@USBR awards $5.1 million in research for new ways to desalinate and treat water

Desalination and water purification research, like this being undertaken at the Brackish Groundwater National Desalination Research Facility in Alamogordo, New Mexico, will help communities treat impaired or otherwise unusable water. Photo credit: Bureau of Reclamation

Here’s the release from the Bureau of Reclamation (Peter Soeth):

The Bureau of Reclamation announced that 30 projects will receive $5.1 million from the Desalination and Water Purification Research Program to develop improved and inexpensive ways to desalinate and treat impaired water.

“We are awarding grants to a diverse group of projects to reduce the cost, energy consumption and environmental impacts of treating impaired or otherwise unusable water for local communities across the country,” said Reclamation Commissioner Brenda Burman. “This funding is a direct result of the Trump Administration’s commitment to increase water supply and delivery through improved technology.” Twenty-five awards are for laboratory-scale projects, which are typically bench scale studies involving small flow rates. They are used to determine the viability of a novel process, new materials or process modifications. Awards are limited to $150,000.

Five projects are selected as pilot-scale proposals, which test a novel process at a sufficiently large-scale to determine the technical, practical and economic viability of the process. Awards are limited to $400,000 and no more than $200,000 per year.

Types of projects funded include modeling, testing new materials such as nanomaterials, and improvements on known technologies such as distillation and electrodialysis. Projects are funded in the following states:

More detail on each project is available at

@USBR selects winners of competition to develop solutions for removing sediment from reservoirs

Paonia Reservoir was at 7 percent full at the end of September. Water year 2018 ranked as the third driest in the Colorado River Basin. Photo credit: Heather Sackett/Aspen Journalism

Here’s the release from the Bureau of Reclamation (Peter Soeth):

Reclamation launched a prize competition seeking new and improved techniques for the removal of sediment and transport of that sediment in a cost-effective manner. Of the 40 potential solutions received, six winners will share $75,000. Sedimentation is a significant problem for aging reservoirs as it reduces the amount of water that can be stored. It also impacts the dam outlets, water quality, recreation and downstream habitat.

“While sediment will never go away, we can seek to minimize its impact and allow the reservoirs to store water for agriculture and cities and minimize the risk of flooding,” said competition co-lead Jennifer Bountry. “The solutions have the potential to be cost-effective while preserving and sustaining the objectives of the reservoir.”

The prize competition sought ideas for the collection of sediment from the reservoir bottom, moving sediment from the collection site to the disposal site and delivering sediments to the downstream channel. Four submissions will each receive $16,250, while two submissions will each receive $5,000.

Two of the four top placing solutions were submitted by Baha Abulnaga with Mazdak International, Inc., of Sumas, Washington, and his proposed transport methods for sediments. His first solution proposed a hydraulic capsule pipeline for topset sediments. His second solution proposed transporting cohesive sediment as a sediment log using a pressurized pipeline. Abulnaga will receive a total prize of $32,500 for his two solutions.

The other top placing solutions receiving $16,250 each provided sediment collection options. Lawrence Kearns of Chicago, Illinois, proposed a Sediment Snake submersible robot for collecting reservoir sediments, and David Orlebeke of Ridgecrest, California, proposed the use of flexible augers.

The remaining ideas selected to receive $5,000 prizes are:

  • Eric Hinterman of Cambridge, Massachusetts, for his collection solution – CryoDredger utilizing inert liquid nitrogen. Hinterman collaborated with Barret Schlegelmilch, Phil Ebben, and Steve Link on the development of his solution.
  • Team of Pradeep Nalabalapu of Round Rock Texas, and Olivier Loidi of Toulouse, Midi-Pyrenees for their solution to collect reservoir sediments using adapted electro-coagulation methods.
  • “We are now planning for the next stage of the prize competition and determining how best to work with the winning solutions to conduct more testing to verify or enhance their practical application for collecting or transporting reservoir sediment,” said competition co-lead Tim Randle.

    The Bureau of Reclamation partnered with the U.S. Army Corps of Engineers, Federal Energy Regulatory Commission, Natural Resource Conservation Service and American Rivers on various aspects of this prize competition.

    To learn more about this prize competition and other competitions Reclamation has hosted, please visit

    Aspinall Unit operations update: 2150 cfs expected in the Black Canyon

    From email from Reclamation (Erik Knight):

    Releases from the Aspinall Unit will be increased by 650 cfs between Tuesday and Wednesday, July 9 and 10. This release increase is necessary to prevent Blue Mesa Reservoir from overfilling. At the current release rate it is projected that Blue Mesa Reservoir would spill within 2 weeks. The current forecast for the April-July runoff volume for Blue Mesa Reservoir is 1,060,000 AF of inflow, which is 157% of average. Flows in the lower Gunnison River are currently above the baseflow target of 1500 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 1500 cfs for July and August.

    Currently, diversions into the Gunnison Tunnel are 850 cfs and flows in the Gunnison River through the Black Canyon are around 1500 cfs. After this release change Gunnison Tunnel diversions will still be 850 cfs and flows in the Gunnison River through the Black Canyon will be around 2150 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

    Black Canyon of the Gunnison

    @USBR announces $29.1 million in WaterSMART grants to use water more efficiently #conservation

    The Government Highline Canal, in Palisade. The Government Highline Canal near Grand Junction. The Grand Valley Water Users Association, which operates the canal, has been experimenting with a program that pays water users to fallow fields and reduce their consumptive use of water. Photo: Brent Gardner-Smith/Aspen Journalism

    Here’s the release from Reclamation (Peter Soeth):

    Projects will help communities bolster water supply

    The Department of the Interior’s Bureau of Reclamation announced that 13 states will utilize $29.1 million in grants from the WaterSMART Program to help communities conserve water.

    “Existing water and hydropower resources are being strained as our infrastructure ages and population grows. The WaterSMART program provides critical support to western communities, helping to best conserve limited water resources,” said Secretary of the Interior David Bernhardt.

    Forty-five projects will be funded based on two categories. In the first category, 28 projects from 11 states were selected to share $7.5 million with each project receiving up to $300,000 in federal funding and having a completion timeframe of less than two years. The second category consists of 17 projects from seven states, sharing $21.5 million. These projects are receiving up to $1.5 million in federal funding and will be completed within three years.

    “These water and energy efficiency grants help increase hydropower production and contribute to water supply reliability in the western United States,” said Reclamation Commissioner Brenda Burman. “WaterSMART is an opportunity for communities to use water more effectively and reduce risk for future water conflict.”

    Projects in Arizona, California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, Oklahoma, Texas, Utah, Washington and Wyoming were selected to receive grants. Examples of projects that are receiving funding include replacing unlined canals with pipe or a lining, installing flow measurement for real-time monitoring of water deliveries, advanced meters for residences that will help inform them about water use, or improving irrigation scheduling by installing moisture probes and irrigation system monitoring.

    The Colorado River Indian Tribes in southwest Arizona will use $250,000 of federal funding with $250,000 of its own funding to modernize its Supervisory Control and Data Acquisition system to enable enhanced irrigation water control and management. The project is expected to result in annual water savings of 10,000 acre-feet that is currently lost to operational spills and evaporation.

    The Grand River Diversion

    The Grand Valley Water Users Association [ed. emphasis mine], near Grand Junction, Colorado, will combine $178,884 in federal funding with $220,000 of its own funding to implement several improvements at Roller Dam to collect more accurate and reliable diversion and measurement information. The project is expected to save 4,000 acre-feet of water every year and will result in reduced diversions from the Colorado River, benefitting a critical stretch of river known as the 15 Mile Reach, which is designated a critical habitat for many fish species.

    The Mission Springs Water District, located in southern California, will combine $300,000 in federal funding with $3.4 million of its own funding to upgrade 12,967 residential water meters to advanced meters that help inform about leaks, breaks and other unusual use patterns. The project is expected to result in annual water savings of 549 acre-feet, which will reduce the amount of water pumped from the Coachella Valley Groundwater Basin.

    Some projects complement on-farm improvements that can be carried out with the assistance of the U.S. Department of Agriculture’s Natural Resources Conservation Service to accomplish coordinated water conservation improvements. A number of the projects selected today are expected to help make additional on-farm improvements possible in the future, including the West Cache Irrigation Company located in northern Utah. They will combine $400,000 in federal funding with $520,000 of their own funding to convert 2.25 miles of the earthen South Fields Canal to a pressurized pipeline. The project is expected to result in water savings of 1,222 acre-feet annually. Once completed, irrigators will be able to take advantage of the newly pressurized system to complete on-farm improvements, potentially funded by the NRCS through its Environmental Quality Incentives Program, such as converting from flood irrigation to more efficient sprinkler irrigation.

    Learn more about all of the selected projects at

    Through WaterSMART, Reclamation works cooperatively with states, tribes, and local entities as they plan for and implement actions to increase water supply reliability through investments to modernize existing infrastructure and attention to local water conflicts. Visit to learn more.

    @USBR lowers five year risk rating for #LakeMead and #LakePowell #ColoradoRiver #COriver #aridification

    Reduced risk of shortfalls at Lake Powell and Lake Mead. Graphic credit Reclamation via John Fleck

    From InkStain (John Fleck):

    Modeling done in January showed significant risk – a nearly one in three chance – of Lake Mead dropping below elevation 1,025 by 2024, a level that would place the reservoir’s long term ability to make deliveries at risk. That has dropped to a one-in-30 chance, according to the new USBR modeling.

    At Lake Powell, the risk of reaching elevation 3,525, a danger point beyond which power generation and the Upper Basin’s ability to meet Colorado River Compact delivery obligations are at risk, has dropped from a one in four chance by 2024 to a one in 25 chance. The chance of dropping below Powell’s minimum power pool – the point at which the reservoir is too low to generate electricity – has dropped from one in six to essentially zero.