#Climate’s toll on the #ColoradoRiver: ‘We can weather maybe a couple of years’ — AZCentral #COriver #aridification #ActOnClimate

Colorado River “Beginnings”. Photo: Brent Gardner-Smith/Aspen Journalism

Click here to read Ian James’ fantastic article about the current state of the Colorado River from stem to stern that’s running up at AZCentral.com. Click through and read the whole article. Here’s an excerpt:

The warming climate is intensifying drought, contributing to fires and drying out the river’s headwaters, sending consequences cascading downstream.

ROCKY MOUNTAIN NATIONAL PARK, Colorado — Beside a river that winds through a mountain valley, the charred trunks of pine trees lie toppled on the blackened ground, covered in a thin layer of fresh snow.

Weeks after flames ripped through this alpine forest, a smoky odor still lingers in the air.

The fire, called the East Troublesome, burned later into the fall than what once was normal. It cut across Rocky Mountain National Park, racing up and over the Continental Divide. It raged in the headwaters of the Colorado River, reducing thick forests to ashes and scorching the ground along the river’s banks.

The fires in Colorado spread ferociously through the summer and fall of 2020 after months of extreme heat that worsened the severe drought.

As smoke billowed over the headwaters, the wildfires raised warning signs of how profoundly climate change is altering the watershed, and how the symptoms of heat-driven drying are cascading down the heavily used river — with stark implications for the entire region, from Colorado’s ranchland pastures to the suburbs of Phoenix…

Over the past year, the relentless hot, dry months from the spring to the first snows left the soil parched. The amount of runoff into streams and the river dropped far below average. With reservoirs sinking toward new lows, the risks of shortages are growing.

Much of the river’s flow begins as snow and rainfall in the territory of the Colorado River Water Conservation District, which includes 15 counties on Colorado’s West Slope. Andy Mueller, the district’s general manager, said the extreme conditions over the past year offer a preview of what the region should prepare for in the future.

“Climate change is drying out the headwaters,” Mueller said. “And everybody in the Colorado River Basin needs to be concerned.”

Mueller saw the effects while backpacking in Colorado’s Holy Cross Wilderness in the summer with his 19-year-old daughter. Above the tree line, at an elevation of 12,000 feet, they expected to see mushy green tundra. Instead, they found the ground was bone dry…

People who focus on the river have widely acknowledged the need to adjust to a shrinking system with less water to go around.

Many suggest solutions can be achieved through collaborative efforts — often with money changing hands in exchange for water — while working within the existing rules. Others say solutions shouldn’t fall on the backs of farming communities by taking away water that fuels their economies. Some people argue the river seems headed for a crash and its rules need to be fundamentally reimagined…

The deals between the seven states are designed to temporarily lower the odds of Lake Mead and Lake Powell dropping to critical lows over the next five years. The states’ representatives have yet to wade into the details of negotiations on what shortage-sharing rules will look like after 2026, when the current agreements expire.

Still unresolved are difficult questions about how to deal with the shortfall over the long term.

What’s increasingly clear is that the status-quo methods of managing the river are on a collision course with worsening scarcity, and that eventually something will have to give…

Watershed ‘thirstier’ with heat

Last winter, after a dry year, the Rocky Mountains were blanketed with a snowpack that was slightly above average. Then came extremely hot and dry conditions, which shrank the amount of runoff and flows into tributaries and again baked the soils dry.

[Andy] Mueller said the change occurred abruptly at the end of the snow season in the spring…

With the heat, some of the snow didn’t melt but instead evaporated directly into the air, which scientists call sublimation — something that has been happening more over the past two decades. The flows in streams dropped over the next few months, and then August brought record heat, which dried out the headwaters and fueled the fires through the fall…

In a 2018 study, scientists found that about half the trend of decreasing runoff in the Upper Colorado River Basin since 2000 was the result of unprecedented warming. In other research, scientists estimated the river is so sensitive to warming that it could lose roughly one-fourth of its flow by 2050 as temperatures continue to rise…

“A warmer atmosphere is a thirstier atmosphere, and we’re seeing less runoff bang for our precipitation buck,” said Jeff Lukas, an independent climate researcher in Colorado. “We’ll still have wetter and drier years, but the baseline is very likely to be shifting downward, as it has in the last 20 years.”

And when extreme heat comes, it leaves less water running in tributaries and also translates into drier forests, leading to increased fire risk.

The soils were so dry over the past year that they soaked up moisture, contributing to below-average stream flows, said Megan Holcomb, a senior climate change specialist with the Colorado Water Conservation Board.

“You can think of it as like the dry sponge that you haven’t wetted in forever,” Holcomb said. “That kind of soil moisture deficit is not something that you rebound from immediately.”

Lake Powell, behind Glen Canyon Dam, shows the effects of persistent drought in the Colorado River Basin. (Source: U.S. Bureau of Reclamation)

After the hot spring came a dry summer. The lack of monsoon rains compounded the drought. And then came August, Holcomb said, when a map of record-hot temperatures hugged the Colorado River Basin like a “massive red handprint.”

In areas of western Colorado that drain into the river, it was the hottest and driest August on record, breaking the previous temperature record by 2 degrees F, said Russ Schumacher, Colorado’s state climatologist and director of the Colorado Climate Center.

The state usually gets its largest wildfires in June and July. But with the severe drought, the fires burned through August, and then exploded in October with unprecedented speed and intensity. The ultradry conditions, together with high winds, contributed to the three largest wildfires in Colorado history, which together devoured more than half a million acres.

In the future, rising temperatures will lead to more of these scorching summers.

Abby Burk of the conservation group Audubon Rockies noticed how low the river was in the summer when she went paddling in her kayak. In parts where the river was full and muddy a year earlier, she found bars of gravel. Where there once were channels to paddle through, she encountered dead-end lagoons.

In November, when Burk drove through the headwaters near the smoldering fires, she snapped photos of the hills and mountains, still golden-brown beneath a dusting of snow.

When the soil is so parched, it will always “take the first drink” before water reaches the streams, Burk said. “We need a lot more snow for many years to come to really replenish the soil moisture deficits that we’re seeing now.”

The fire scars will also bring challenges come spring, she said, when melting snow will send runoff carrying ash, debris and sediment into streams, potentially creating complications for water systems.

Burk said she’s hoping there will be a slow melt so the runoff comes gradually, without “bringing down the mountain into the river.”

Rancher and fly-fishing guide Paul Bruchez raises cattle on 6,000 acres near Kremmling. Bruchez has taken an active role in Colorado River issues ever since his family suffered from a critical water shortage during the 2002 drought. Photo credit: Russ Schnitzer via Aspen Journalism

A rancher looks to adapt

Paul Bruchez raises cattle on his family’s ranch in the headwaters near the town of Kremmling, where the Colorado River winds through pastures…

Bruchez has been involved in discussions about the river as a member of the Colorado Basin Roundtable. And while he’s heard many people voice alarm about the watershed lately, Bruchez said he and other neighboring ranchers have been talking about the need to adapt to a river with less water since 2002, when severe drought came.

The flows dropped so low then that even ranchers with the longest-standing water rights, known as senior rights, couldn’t get it to their fields.

“Within this river basin, we have seen a change over time of the quantity and volume of water that is available. And in that same time, we’ve seen a growth of population that relies on it,” Bruchez said. “We knew this in 2002 when we hit that drought, that if we didn’t change how we operated, we weren’t going to survive.”

Since then, Bruchez and other ranchers have been talking about ideas for adapting…

The closer the region gets to a scenario of curtailing water allotments, Bruchez said, the more investors and representatives of cities and towns are going to be contemplating ways of securing water from elsewhere.

For people in agriculture, he said, “we need to be at the table or we’re going to be on the menu.”

[…]

Blue Mesa Reservoir, Curecanti National Recreation Area. Photo credit: Victoria Stauffenberg via Wikimedian Commons

‘It affects everybody’

One of the main tributaries that feeds the Colorado is the Gunnison River, which like the mainstem has shrunk during the heat-amplified drought. Along the Gunnison, cattle ranchers got less water last year and their pastures produced less hay.

The river’s low flows also forced an early end to the river rafting season on Labor Day weekend. After that, releases from a dam had to be cut back and the Gunnison was left much shallower than usual, with rocks protruding in stretches where boats would normally be drifting until the end of September.

Sonja Chavez via Gunnison Basin Roundtable.

The river has dropped to some of its lowest levels in years, said Sonja Chavez, general manager of the Upper Gunnison River Water Conservancy District.

The effects are visible at Blue Mesa Reservoir, one of the state’s largest, which has declined to less than half its full capacity.

Visiting the lake, Chavez walked on sandy ground that used to sit underwater.

Looking across the inlet where the river pours into the lake, she pointed to a gray line on the rock showing the high-water mark. During spring runoff, she said, the river in this channel can reach about 20 feet higher. But with the soil so parched, its level dropped.

“When we are dry in the Upper Gunnison Basin, it affects everybody downstream of us,” Chavez said. And the swings between high and low flows, she said, have made it difficult to plan how to operate the reservoirs…

In the Gunnison Valley, a local climate action group meets to talk about potential solutions. Some conversations have focused on how to manage forests that have grown thick with vegetation over the past century as federal agencies have focused mostly on putting out fires.

While the forests have grown thicker, warmer temperatures have enabled beetles to flourish, littering the mountains with dead trees.

Chavez and others want to prioritize efforts to make the forests healthier and more fire-resilient by thinning the trees through logging, mechanical treatments or controlled burns, which they say would make the whole watershed healthier. She said the federal government needs to be more involved and the region needs funding for these projects.

“Our big push this year is to do some watershed management planning and work with the Forest Service to identify zones of concern, or areas that we can treat,” Chavez said. “We’re worried if we had a big fire what would happen.”

Alongside those efforts, water managers are discussing ways of dialing down water usage…

Ranchers, farmers consider using less

One lifelong rancher who had a smaller-than-usual hay crop was Bill Trampe, who has worked on water issues for years as a board member of the Colorado River District.

His cattle graze on meadows near Gunnison where the grasses survive year after year. He was short of water to irrigate after mid-June, which left the pastures parched.

Palisade is just east of Grand Junction and lies in a fertile valley between the Colorado River and Mt. Garfield which is the formation in the picture. They’ve grown wonderful peaches here for many years and have recently added grape vineyards such as the one in the picture. By inkknife_2000 (7.5 million views +) – https://www.flickr.com/photos/23155134@N06/15301560980/, CC BY-SA 2.0,

Over the past two decades, only a few years brought good snowpack, he said, and ranchers have repeatedly had to weather the financial hits of years when they must buy hay for their cattle…

‘We need to set the terms’

In other parts of the river basin, some representatives of agricultural water agencies are worried about the potential consequences of paying farmers to leave land dry.

One such voice is J.B. Hamby, a newly elected board member of California’s Imperial Irrigation District, who said he’s concerned that while cities and sprawling suburbs continue to grow rapidly, agricultural communities are increasingly at risk. He said people in cities need to realize there is a priority system that shouldn’t be changed…

Arizona gets nearly 40% of its water from the Colorado River. Much of it flows in the Central Arizona Project Canal, which cuts across the desert from Lake Havasu to Phoenix and Tucson.

In 2020, Arizona and Nevada took less water from the river under the drought agreement among Lower Basin states, and in 2021 they will again leave some of their water in Lake Mead. The latest projections show Mead could fall below a key threshold by summer, which would trigger a shortage declaration and larger cutbacks in 2022…

Now, with less water flowing to farms, the amount of runoff into the Salton Sea has shrunk, leaving growing stretches of exposed lakebed that spew dust into the air. The dust is contributing to some of the worst air pollution in the country, and many children suffer from asthma.

Hamby said the Imperial Valley would have been better off without the water transfer deal. Looking at the proposed approach in Colorado, Hamby said, it seems to replicate what occurred in Imperial.

“When you tie money to water, you get users who become addicted to the money and don’t actually in the end start to want to farm anymore,” Hamby said. “That is really corrosive to the long-term survival, much less thriving, of rural communities when people get more hooked on money rather than the way of life and putting the water on the land.”

He argued that such an approach would be “subverting the whole priority system” and enabling cities to avoid taking cuts themselves…

‘Are we doing enough?’

At his ranch by the river, Bruchez said he wants to be on “the preventative side,” getting ahead of the looming problems instead of reacting. And that includes studying and promoting conservation, he said, because the bottom line is “we just all have to figure out how to use less water.”

In early 2019, Bruchez began talking with Perry Cabot, a researcher from Colorado State University, about a project that would help provide data on crop water use, impacts of reduced irrigation and strategies for conserving water.

Cabot gave a presentation to the Colorado Basin Roundtable, and members supported the idea of a study. The project began in 2020 with about $900,000 in funding, including support from the Colorado Water Conservation Board and groups including Trout Unlimited and American Rivers.

A group of nine ranchers participated and were paid for leaving some fields dry or partially dry, Bruchez said. More than 900 acres weren’t irrigated for the entire year, and about 200 acres were “deficit irrigated,” meaning they received less water.

Bruchez’s ranch totals about 6,000 acres. He participated on about 41 acres, where he stopped irrigating on June 15 and didn’t water the rest of the year.

“My end goal is to understand the impacts of water conservation for agriculture so that if and when there are programs to participate, agriculture is doing it based on science,” Bruchez said…

Paul Bruchez said he’s seen that when people talk about solutions, they often seem to draw boxes around different approaches like demand management, water conservation, climate change and forest management, but he thinks they’re all quite connected.

“It’s all the same conversation,” Bruchez said. “To me, the question just comes down to, are we doing enough, quick enough?”

[…]

“It’s that water that is provided by the Colorado River that ties us all together,” Mueller said. “And truly, when we recognize the importance of the Colorado River and how it ties us together, that’s when we succeed as a society.”

Ian James is a reporter with The Arizona Republic who focuses on water, climate change and the environment in the Southwest. Send him story tips, comments and questions at ian.james@arizonarepublic.com and follow him on Twitter at @ByIanJames.

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