Pearl Harbor altered Colorado’s path after 1941, and Covid-19 will also — The Mountain Town News #coronavirus #COVID19

Boring of the Eisenhower Tunnel began in 1968 and was completed in 1973 at a cost of $117 million. The Colorado Department of Transportation estimated the cost early in the 21st century would have been $1 billion to $1.1 billion. Photo/ C-DOT.

From The Mountain Town News (Allen Best):

This pandemic has started feeling like something more than an extended snow day or having the mumps when you’re a child. Perhaps it’s now more like 1941, after Pearl Harbor.

The potential for a pandemic has been amply reported over the years. People in the early 1940s knew we would inevitably go to war. When abstraction became reality on that December day, so much changed in the context of Colorado.

In the late 1930s, ski areas were about to blossom. The Union Pacific’s Averell Harriman in 1936 opened Sun Valley in Idaho, and resorts were taking off in New England. Colorado had a few smaller ski areas, including Berthoud and Winter Park, plus town ski areas at Steamboat Springs and Gunnison.

Others were thinking bigger. In Aspen, a boat-tow had been installed, primitive but effective in transporting people uphill. One of them was Elizabeth Paepcke, the wife of a wealthy Chicago industrialist. She wanted her husband to see Aspen, to see the potential she saw. Others saw a different resort, one on Mount Hayden, in the Castle Creek Valley southwest of Aspen. Colorado legislators gave the venture $650,000, which was backed by a federal fund.

Closer to Denver, tunnel crews had begun boring an exploratory tunnel under Loveland Pass, with the idea of creating a highway under the Continental Divide. To the west, the state government had used federal New Deal funding to upgrade the horse trail across the Gore Range to a two-lane gravel road. They called it Vail, to honor Charlie Vail, then the boss of the Colorado Highway Department.

In Washington, D.C., President Franklin Roosevelt had had engineers develop plans for a national system of highways with separated lanes.

In Colorado, work had begun on Green Mountain Reservoir. The intent was to provide a service to the Western Slope as a result of the giant trans-mountain diversion planned at Grand Lake to benefit farmers in northeastern Colorado.

And in northeastern Colorado, my father was working on a dryland farm near Fort Morgan and lopping off the tops of sugar beets in that quiet before the distant clouds of war arrived.

Pearl Harbor changed everything.

The war brought the 10th Mountain Division to Colorado, to a high valley along the Continental Divide between Leadville and Red Cliff called Eagle Park. The Army named it Camp Hale, and at the height of the training it was among the largest cities in Colorado, with 14,000 people, mostly men.

After the war, in 1946, Elizabeth Paepcke’s husband, Walter, finally visited Aspen and saw what had so impressed her. But he put a new touch on it, the idea of invigorating the body and challenging the mind, a DNA that lingers to this day. 10th Mountain Division veterans returned in droves to Colorado to convert Aspen from a derelict mining town into an international resort. A resident, for a time, was Pete Seibert, who had grown up in New England dreaming of creating a ski resort. But he wanted his own resort. That dream in 1962 became Vail.

In time, my father was inducted into the Army, leaving behind the dryland farm where he was reared and its house, which had neither indoor plumbing nor electricity, and took the train to California for basic training, then a posting at the Presidio, near the Golden Gate Bridge in San Francisco. Eventually he was shipped to India at the foot of the Himalaya Mountains.

The bore under Loveland Pass was completed in 1943, but it revealed too much difficult geology for a highway tunnel. Later, a different alignment was chosen, and that tunneling work resulted in the first of two tunnels in 1973.

The idea of superhighways that many people want to attribute with singularity to Dwight Eisenhower finally was given a federal sponsorship in 1956. Among the Senate sponsors was Albert Gore, father of the future vice president. But if not for the war, it might have happened sooner.

First water through the Adams Tunnel. Photo credit Northern Water.

As for that big New Deal-era water project, the Colorado-Big Thompson, it was finally completed in 1957.

And my father returned to northeastern Colorado, married the girl he had met at a gathering of young Baptists in the 1930s and took up work as a carpenter. He never flew again, never traveled abroad, but he did have a taste for curry that was never satisfied. He died before the spread of Indian restaurants in Colorado.

Vail probably would have happened eventually. The mountain itself and the proximity to Denver made it a natural. But World War II put Pete Seibert into Colorado. Aspen would have flourished, but perhaps in a different way. As for Mount Hayden, it came to nothing, in its own way perhaps a casualty of World War II.

This pandemic is different than World War II, and we have to go back further to see precedent. In 1918, Gunnison quarantined itself and survived with little loss of life, while Silverton, as remote a town as there may be in Colorado, isolated in the icy fastness of the San Juan Mountains, lost 10% of its population.

In this COVID-19 pandemic, the first case in Colorado was a visitor to Summit County who had recently been in Italy, then Australian visitors to Aspen-Snowmass. But then Eagle County flared, and as of early this week had 22 cases from the Vail area compared to 24 in Denver County, which has a population about 12 times as large. County officials on Thursday said they suspected hundreds, if not thousands, had contracted COVID-19.

A century ago the influenza spread globally, but by rail instead of by air. The world has shrunk, with consequences both good and bad.

We will survive this pandemic, but there will be changes. I sincerely doubt we’ll see the significant expansion at DIA that had been announced just a few months ago. That may actually be good.

Can other good also result? Many of us hope that it will result in greater acceptance of facts, more acceptance of science. Ideology played a powerful role in the sluggish, or worse, acceptance of the virus by powerful people, most notably the president. That same ideology, the same denial, has shrugged off or rejected the power of accumulating greenhouse gases to produce costly changes in our climate.

I hope we develop a greater sense of a global community. It could easily take us the other way, one exemplified by the run on guns and ammunition. What we see early on, the sniping between President Trump and his counterparts in China, is not encouraging.

This was first posted by the Colorado Independent.

How Colorado’s water conversation has shifted in the 21st century — The Mountain Town News

Xeriscape landscape

From The Mountain Town News (Allen Best):

Water providers have shifted their focus

The Colorado Water Conservation Board, the primary water-policy agency for the state, met last week in Westminster, and afterward I had dinner with a friend. The friend, who has long worked in the environmental advocacy space, spoke of some matter before the board, and added this: “Twenty years ago this conversation never would have happened.”

Water politics in Colorado have undergone a Big Pivot. As the century turned, environmental issues had made inroads into the conversation, but water development remained a dominant theme. Then came the drought of 2002, which more or less changed everything. So has the growing realization of how the changing climate will impact the already over-extended resources of the Colorado River.

Instead of a deep, deep bucket, to be returned to again and again, the Colorado River has become more or less an empty bucket.

Jeff Tejral. Photo via The Mountain Town News

Those realizations were evident in a panel discussion at the Colorado Water Congress about water conservation and efficiency. Jeff Tejral, representing Denver Water, spoke to the “changes over the last 20 years” that have caused Denver Water and other water utilities to embrace new water-saving technology and altered choices about outdoor water use.

Denver Water literally invented the word xeriscaping. That was before the big, big drought or the understandings of climate change as a big, big deal. Twenty years ago, the Colorado Water Congress would never have hosted panels on climate change. This year it had several.

Tejral pointed to the growth in Denver, the skyscrapers now omnipresent in yet another boom cycle, one that has lifted the city’s population over 700,000 and which will likely soon move the metropolitan area’s population above 3 million. That growth argues for continued attention to water efficiency and conservation, as Denver—a key provider for many of its suburbs—has limited opportunities for development of new supplies. “The other part of it is climate change,” he said. “That means water change.”

Denver Water has partnered with a company called Greyter Water Systems on a pilot project involving 40 homes at Stapleton likely to begin in June or July. It involves new plumbing but also water reuse, not for potable purposes but for non-potable purposes. John Bell, a co-founder of the company, who was also on the panel, explained that his company’s technology allows water to be treated within the house and put to appropriate uses there at minimal cost.

“It makes no sense to flush a toilet with perfectly good drinking water, and now with Greyter, you don’t have to,” he said.

For decades Denver has had a reuse program. Sewage water treated to high standards is applied to golf courses and other landscaping purposes. Because of the requirements for separate pipes—always purple, to indicate the water is not good for drinking—its use is somewhat limited.

A proposal has been moving though the Colorado Department of Public Health rule-making process for several years now that would expand use of greywater and set requirements for direct potable reuse. The pilot project at Stapleton would appear to be part of that slow-moving process.

Greyter Water Systems, meanwhile, has been forging partnerships with homebuilders, the U.S. Department of Defense, and others in several small projects.

“It seems like 40 homes in Colorado is a small step,” said Tejral, “but a lot of learning will come out of that, which will open the door for the next 400, and then the next 4,000.”

Colorado transmountain diversions via the State Engineer’s office

There are limits to this, however, as water cannot be recycled unless it’s imported into a basin. Water users downstream depend upon releases of water from upstream. Water in the South Platte River Basin is estimated to have 6 or 7 uses before it gets to Nebraska.

In the Eagle River Valley, the streams gush with runoff from the Gore and Sawatch ranges, but there can be pinches during years of drought. That area, said Linn Brooks, who directs the Eagle River Water and Sanitation Districts, has a population of between 35,000 and 60,000 between Vail and Wolcott, “depending where we are during our tourist year.”

Water efficiency programs can make a big difference in what flows in the local creeks and rivers. Brooks pointed to 2018, a year of exceptionally low snowfall. New technologies and policies that put tools into the hands of customers reduced water use 30% during a one-month pinch, resulting in 8 cubic feet per second more water flowing in local creeks and rivers. During that time, Gore Creek was running 16 cfs through Vail. It flows into the Eagle River, which was running 25 cfs. “So saving 8 cfs was really significant,” she said.

Many of Eagle Valley’s efficiency programs focus on outdoor water use. That is because the water delivery for summer outdoor use drives the most capacity investment and delivery expenses. “Really, that is the most expensive water that we provide,” Brooks said.

Tap fees and monthly billings have been adjusted to reflect those costs. One concept embraced by Eagle River Water and Sanitation is called water budgeting. “Our hope is that water budgeting will continue to increase the downward trend of water use per customer that we’ve had for the last 20 years for at least another 10 years,” she said.

Linn Brooks. Photo via The Mountain Town News

Eagle River also has tried to incentivize good design. The district negotiates with real estate developers based on the water treatment capacity their projects will require. “That is a way to get them to build more water-efficient projects, especially on the outdoors side,” explained Brooks. “When we execute these agreements, we put water limits on them. If they go over that, we charge them more for their tap fee. That can be a pretty big cost. We don’t like to do that, but we have found that in those few cases where new developments go over their water limits, we have gone back to them and said, we might have to reassess the water tap fees, but what we really want you to do is stay within your water budget.” That tactic, she added, has usually worked.

In this concept of water budgeting, she said, “I don’t think we have even begun to scrape the surface of the potential.”

Outdoor water use has also been a focal point of efforts by Northern Colorado Water Conservancy District, the agency created to deliver water to customers from the trans-mountain diversion at Grand Lake. Municipalities from Broomfield and Boulder north to Fort Collins and Greeley, even Fort Morgan, get water from the diversion.

Frank Kinder was recently hired away from Colorado Springs Utilities to become the full-time water efficiency point person for Northern. Part of the agency’s effort is to introduce the idea that wall to wall turf need not be installed for a pleasing landscape. Instead, Northern pushes the idea of hybrid landscapes and also introduces alternatives for tricky areas that are hard to irrigate. The ultimate goal falls under the heading of “smiles per gallon.” Some of the district’s thinking can be seen in the xeriscaping displays at Northern’s office complex in Berthoud.

Kevin Reidy, who directs water conservation efforts for the Colorado Water Conservation Board, said the Colorado Water Plan posited a goal of reducing water use by 400,000 acre-feet. Don’t get caught up in that precise number, he advised. “It’s really about trying to figure out a more stable water future for our cities,” he said.

Readers might well be confused by an agency named “water conservation” having an employee with the title of “water conservation specialist.” The story here seems to be that the word conservation has changed over time. In 1937, when the agency was created, water conservation to most people meant creating dams and other infrastructure to prevent the water from flowing downhill. Now, conservation means doing as much or more with less.

On why Eagle River Water takes aim at outdoor use

The amount of water used outdoors is generally twice that used for indoor purposes, and only about 15% to 40% of water used outdoors makes its way back to local waterways.

None of this water is returned to local streams through a wastewater plant. Most of the water is consumed by plant needs or evaporation; what is leftover percolates through the ground and may eventually make its way to a local stream.

— From the Eagle River Water website

This was originally published in the Feb. 18, 2020, issue of Big Pivots.

Sedimentation problems necessitate diversion structure overhaul for Lake Nighthorse intakes

From The Farmington Daily Times (Hannah Grover):

No water will be pumped from the Animas River into Lake Nighthorse this year.

That is because the headgates at the dam southwest of Durango, Colorado, have to be destroyed and replaced, according to Animas-La Plata Project Operations, Maintenance and Repair Association General Manager Russ Howard.

Howard told the San Juan Water Commission on March 4 that the $6.5 million project is needed because the design was not appropriate for the location. This work is being done by the U.S. Bureau of Reclamation.

He said work was also done prior to choosing to replace the gate. Howard said $1.5 million was spent “over the years trying to put a Band-Aid on something that shouldn’t have been there in the first place.”

When asked about the gate, Howard said the design, known as an Obermeyer, gate is not a bad design, but it was not appropriate for the Animas River.

Lake Nighthorse and Durango March 2016 photo via Greg Hobbs.

U.S. Bureau of Reclamation spokeswoman Justyn Liff agreed with Howard that the design was a good design but was not compatible with the Animas River’s conditions. She said on another river it would have worked fine, but the bureau had not realized how muddy the Animas River is.

The amount of mud in the Animas River caused problems and filled the pipes with mud.

In addition to the $6.5 million replacement of the headgates, Liff said the the gate’s original construction, retrofits to keep them operational and engineering studies and design cost about $6.2 million.

New study predicts less water in #ColoradoRiver as #Utah considers its #LakePowell Pipeline — The St. George Spectrum #COriver #aridification

This $2+ billion project would pump 28 billion gallons of water 2,000 feet uphill across 140 miles of desert to provide just 160,000 residents in Southwest Utah with more water. Graphic credit: Utah Rivers Council

From The St. George Spectrum (Lexi Peery):

Climate change is increasing the variability of the Colorado River so much so that the river could lose one-fourth of its flow by 2050, according to a new government study.

As plans for the 140-mile Lake Powell Pipeline — which would divert over 86,000 acre-feet annually from the reservoir to southwestern Utah — are under review by the Bureau of Reclamation, what does the Colorado River’s diminishing flows mean for the project?

The new report, produced by the U.S. Geological Survey and published in Science, attributes a 16% decline in the river’s flow from 2000-2017 to rising temperatures. The Colorado River hydrates seven downstream states, storing water in shrinking Lake Powell and Lake Mead reservoirs.

Washington County Water Conservancy District Manager Zach Renstrom said he thinks the variability of climate change provides even more reason for the county to pursue the pipeline.

“Climate change is a big deal to us, we are very concerned about it, and specifically how it’s going to affect our watershed,” Renstrom said. “When we look at these dynamics, they’re one of the strong arguments for the Lake Powell Pipeline because we need to make sure to have a robust infrastructure in place so we can adjust for (climate change).”

Rising temperatures, less snow

Seen from the air, Glen Canyon Dam holds back the Colorado River to form Lake Powell. The state of Colorado is looking into how to fund a program that would pay irrigators to reduce their consumptive use in order to send water downstream to a savings account in Lake Powell. Photo credit: Brent Gardner-Smith/Aspen Journalism

USGS scientists considered two scenarios of climate change in the Colorado River study. In one, warmer temperatures by 2050 would reduce the amount of water flowing in the river by 14-26%. In the other scenario, warming would take away 19-31% of the river’s flow…

Milly and fellow USGS scientist Krista Dunne focused on the reflectivity of snow, known as albedo, as a key element in the river’s sensitivity to warming. They zeroed in on the role of snow cover as a “protective shield” for water in the river basin.

Milly likened the flowing river to the leftovers of the “meal” of snow and rain that falls across the basin after evaporation has “eaten” its share…

And the amount consumed by evaporation is driven by how much energy the basin absorbs in the form of sunlight. The snow cover in the Rocky Mountains reflects back to the sky and space a significant fraction of the sunlight.

As the world gets hotter with the burning of fossil fuels, more of the precipitation falls as rain instead of snow. And the snow melts away earlier in the year. As the snow cover in the mountains is progressively lost, the river basin absorbs more energy…

“When we talk about structural deficits and overuse of the Colorado River system, it’s exclusive to the lower basin,” WCWCD spokesperson Karry Rathje said.

Washington County’s population is projected to grow 229% by 2050, but Renstrom says he’s worried that growth may come sooner than expected. He’s pushing to get the pipeline going in the next 10 years in order to diversify the county’s water supply.

“Even when we look at reduced flows … the water in the Lake Powell Pipeline should be available for us to withdraw,” Renstrom said. “As the guy who has to worry about where water is coming from in 30 years if some of the higher-end climate models come to pass, and the Virgin River is dried up, it makes me feel very secure that we’ll have another tool in that toolbox.”

Utah Rivers map via Geology.com

The latest @Northern_Water E-Waternews is hot off the presses

Southern Water Supply Project Map via Northern Water.

Click here to read the newsletter. Here’s an excerpt:

Final pipeline pieces get put into place for Southern Water Supply Project II

The contractors for the Southern Water Supply Project II reached a significant milestone last month with the installation of the final portion of pipeline.

The final piece was placed along the 20-mile route near Carter Lake in southern Larimer County. The pipeline, funded by the City of Boulder, Left Hand Water District, Longs Peak Water District and the Town of Berthoud, will bring water supplies to those communities year-round.

While the installation of pipeline is complete, additional work remains. Northern Water technicians are installing and programming equipment for integration into its SCADA system, and testing of the pipeline segments for quality assurance is ongoing. Northern Water anticipates the pipeline will start carrying water to its destination at Boulder Reservoir in April.

Beyond the pipeline, however, work will continue on another important aspect of construction: reclamation of disturbed ground. The pipeline runs through easements on a variety of public and private properties, and reclamation crews will be working with those entities to ensure lands are reclaimed to their owners’ satisfaction.

Garney Construction was the lead contractor for the $44 million project.

A video of the final pipeline is available here.

To learn more, go to http://swsp2.org.

As 2020 kicks in, historic #ColoradoRiver #Drought Plan will get its first test — @WaterEdCO

Lake Powell, created with the 1963 completion of Glen Canyon Dam, is the upper basin’s largest reservoir on the Colorado River. But 2000-2019 has provided the least amount of inflow into the reservoir, making it the lowest 20-year period since the dam was built, as evidenced by the “bathtub ring” and dry land edging the reservoir, which was underwater in the past. As of October 1, 2019, Powell was 55 percent full. Photo credit: Eco Flight via Water Education Colorado

From Water Education Colorado (Laura Paskus):

This year, the first-ever Colorado River Drought Contingency Plan is set to launch, and water officials expect 2020 to bring unprecedented changes to the way the river is run, including cutbacks in water use by some states.

Drought and climate change are expected to play a leading role in determining how to reduce water use and bring the stressed river system into a sustainable, balanced state of being.

After historically low levels were reached last year in Lakes Powell and Mead, Arizona and Nevada are now poised to implement their first-ever cuts in water diversions, while Colorado and the other upper basin states are working to explore ways to conserve water and bank it in Lake Powell’s new drought pool to avoid future shortages.

Brad Udall, a senior climate scientist at Colorado State University’s water center, said the river’s operations are set for a major rework.

2019, he said, was “a really big [water] year, so I think everybody’s happy, but to think somehow the drought is over and climate change isn’t happening—or to hope for the best and ignore the lessons of the last 19 years—I think these high temperatures will remind people, ‘This is not the same old game we used to play in the 20th century.’”

A look back

A lot has changed since the Colorado River Compact first divvied up the river’s waters in 1922. Today, more than 40 million people in two countries rely upon the river, which originates on the Western Slope of the Rocky Mountains in northern Colorado, and is fed by major tributaries like the Green, Gunnison and San Juan rivers. Cities from Denver to San Diego, though geographically outside of the natural river basin, divert water from the river for drinking and industry, and farmers irrigate 5.5 million acres of everything from alfalfa to melons.

The Colorado River Basin is also now more than 2 degrees Fahrenheit warmer than the twentieth century average—with “hotter” droughts depleting river flows. By necessity, as the climate continues to change, bringing continued warming and drying, shortage-sharing agreements on the river must continuously be updated to keep changing, too. The Drought Contingency Plan (DCP) was needed as a stop-gap until a new set of operating guidelines, due by 2026, are written.

The DCP’s predecessor

The DCP’s origins lie with the Colorado River Interim Guidelines. Written in 2007, the operating guidelines were designed to address the Colorado River’s deteriorating storage levels. They identify how to operate the river’s two major reservoirs, Lake Powell and Lake Mead, under hotter, drier conditions, and to share the risk of shrinking water supplies between the upper and lower basins.

But the 2007 interim guidelines, while temporarily keeping the basin out of crisis, did not anticipate the extent of drought that the basin would experience. In 2013, then-Secretary of the Interior Sally Jewell directed states to consider additional measures or face unilateral federal action to avoid a potential crisis. With its own interests to protect, including water deliveries to contractors and tribal water rights, the federal government needed states to put a more robust plan in place.

That led to the latest temporary plan, the DCP, which negotiators say provides some security in avoiding a potential crash of the Colorado River system.

Six years in the making, the DCP includes two plans, hammered out separately by the lower and upper basin states. The upper basin plan focuses on flexibility in reservoir operations during drought conditions, investigating how to reduce water demands—including with voluntary water conservation programs—and weather modification to augment precipitation. In the lower basin, the process needed to move more quickly because water use already exceeds allocations. Cities and farms in Arizona, California and Nevada agreed to scale back and take deeper cuts as Lake Mead reaches threshold elevations that trigger those cutbacks. This summer, the first threshold was triggered, so Arizona and Nevada will implement their cutbacks this year.

Developing plans for each basin was tricky considering that within each state there are also individual tribes, competing interests, and conflicts between urban and rural water users. But, pushed by a deadline from U.S. Bureau of Reclamation Commissioner Brenda Burman, in March 2019, the seven states asked Congress to provide necessary authorizations to execute their final plans. In an era when Congress spends much of its time at an impasse, legislators on both sides of the aisle recognized the need for drought planning. In April, federal legislators passed the Colorado River Drought Contingency Plan Authorization Act and the following month, on May 20, representatives from the seven basin states and Department of the Interior signed completed upper and lower basin drought contingency plans.

Colorado River Basin. Graphic credit: Water Education Colorado

Not a new problem

As Eric Kuhn and John Fleck write in their new book, “Science Be Dammed: How Ignoring Inconvenient Science Drained the Colorado River,” even during compact negotiations in the 1920s, records showed the river’s annual flows were lower than the total 17.5 million acre-feet allocated to the seven states and Mexico. In fact, three different studies during the 1920s estimated natural river flows at Lee Ferry at between 14.3 million acre-feet and 16.1 million acre-feet.

Planners chose to ignore that information, Fleck says, and with it, they ignored convincing evidence showing the basin regularly experienced long periods of drought. “We have rules written down on paper, allocating water across the basin, that essentially allocate more water than the river actually has—and this manifests itself quite differently in the lower basin than the upper basin,” says Fleck, director of the Water Resources Program at the University of New Mexico. Fleck’s co-author Kuhn is the now-retired general manager of the Colorado River Water Conservation District.

In the lower basin, California, Nevada and Arizona have long overused their share of the river (approximately 7.5 million acre-feet annually, averaged over 10-year rolling cycles), Fleck says, whereas the upper basin states have yet to use more than around 4 million acre-feet (of the “remaining” 7.5 million acre-feet originally intended, but not necessarily guaranteed, for them). But everyone needs to come to terms with the fact that there is less water in the basin, Fleck says. “And that’s what the DCP is,” he says. “The first steps toward a long-term plan for everyone to use less water.”

Today, Kuhn and Fleck note, the river’s average flow between 2000 and 2018 has been only 12.4 million acre-feet—16 percent lower than the 1906-2017 average of 14.8 million acre-feet per year.

To use less water, the two basins need their own strategies. In the lower basin, the DCP sets rules to scale back use of lower basin allocations as Lake Mead drops, or until storage conditions improve. Arizona, Nevada and Mexico will see cuts this year, while California could follow in future years if reservoir storage declines continue. Over the past few years, water users already started scaling back voluntarily, and, says Fleck, “The DCP gives the structure that gives us the confidence [the cutbacks] will continue,” he says.

The upper basin occupies a precarious position of its own, even though it uses less water than it technically could under the compacts that govern its use—use in the upper basin has remained flat, at around 4 million acre-feet per year, since 1990. Because upper basin states must not interfere with a specific quantity of water flowing downstream, they’ll take on much of the burden of dealing with declining flows in a warmer future, Fleck adds. “That means the upper basin has to be sure it has the tools in place to make sure it can continue to meet its compact obligations, to send water out of Lake Powell,” he says. “And it may have to figure out how to conserve water below 4 million acre-feet.”

Brad Udall: “…latest version of my 4-Panel plot thru Water Year (Oct-Sep) of 2019 of the #coriver big reservoirs, natural flows, precipitation, and temperature. Data goes back or 1906 (or 1935 for reservoirs.) This updates previous work with
@GreatLakesPeck

Challenges of a warming world

Any planning on the Colorado River—from the crops farmers plant, to the ways in which cities incentivize conservation among customers, to the DCP’s successor—must address the fact that the basin is facing a hotter, drier future.

Rainfall records, reconstructed from tree ring chronologies that stretch back more than a thousand years, reveal past patterns of southwestern droughts, marked by dry conditions associated with natural climate variability. Today’s droughts in the basin are different. They are notable not just for a lack of precipitation, but also for warmer temperatures, which spur changes in snowpack, increase transpiration in forests and fields, and boost evaporation from reservoirs.

The U.S. Global Change Program’s Fourth National Climate Assessment in 2018 painted a troublesome picture of reduced water supplies and future food insecurity in the region. It also identified risks to southwestern tribes from drought and wildfire, and challenges to the region’s infrastructure and energy supplies.

More localized studies of the Colorado River Basin also show that as climate change continues to heat and dry the region, the river’s flows will keep dropping. A 2017 study by Brad Udall, a senior water and climate research scientist at the Colorado Water Institute at Colorado State University and Jonathan Overpeck, dean of the School for Environment and Sustainability at the University of Michigan, showed that flows between 2000 and 2014 averaged 19 percent below the 1906-1999 average, with one-third of those losses due to higher temperatures, versus changes in precipitation. If warming continues, according to that 2017 study, Colorado River flows could decline by 20 to 35 percent by 2050 and 30 to 55 percent by the end of the century.

A study published the following year by Udall and others reiterated that “unprecedented basin-wide warming” was responsible for the declines, this time looking at 1916 through 2014, when the river’s flows dropped by 16.5 percent during that period, even though annual precipitation had increased slightly. The study also revealed the entire basin’s sensitivity to shifts in precipitation patterns—that it matters whether precipitation comes as rain or snow, and also where it falls. Snowfall in the upper basin is more beneficial to the system, for example, than rainfall in southern Arizona. And the future doesn’t look promising: The 2018 study forecasts a future decline in snowfall within four sub-basins in Colorado.

Healthier snowpack this past winter offered everyone a bit of a reprieve, but the Colorado River Basin’s problems aren’t over. At the end of the water year, total system storage was at only 53 percent, according to Reclamation, though that’s up from just under 47 percent in October 2018.

Aspinall Unit operations update: The February 15th runoff forecast for Blue Mesa Reservoir predicts 83% of average for April-July inflows

Aspinall Unit dams

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased to 600 cfs on Wednesday, February 26th. Snowpack in the Upper Gunnison Basin is currently at 103% of normal. The February 15th runoff forecast for Blue Mesa Reservoir predicts 83% of average for April-July inflows. 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 January through March.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 800 cfs. After this release change Gunnison Tunnel diversions will still be at zero and flows in the Gunnison River through the Black Canyon will be around 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.