Drought, climate change, & existential threats along the Colorado River
by Allen Best
From 38,000 feet in a jet, Hoover Dam looks to be a remarkable achievement. The giant plug in the Colorado River about 30 miles outside Las Vegas, the cause of the swathes of blue in the tan desert landscape, stands as a testament to 20th century American ingenuity, stubbornness, and political will.
From the crest of the dam, the achievement looks more flawed. Lake Mead has dropped 130 feet since 2000, when it was full. It’s now at 37 percent of capacity and declining rapidly enough to capture the full attention of water managers from Los Angeles to Denver.
In Phoenix, water managers foresee potential reductions so severe they could “dramatically impact Arizona’s entire economy, society, and the environment,” said Suzanne Ticknor, director of water policy for the Central Arizona Project, or CAP, at a recent forum. She described the risk of what she called “this existential threat” as a low probability that could nonetheless develop quickly and in the relatively near future.
The CAP delivers 1.6 million acre-feet of water annually from the Colorado River through a 336-mile concrete-lined aqueduct to four million people, including 10 irrigation districts and 11 tribes. Built in the 1970s and 1980s, it was financed by the federal government.
Terms of that financing included an import provision: Arizona, along with Nevada, would have to bear the brunt of reduced flows, if there are any. Only later, according to a protocol agreed to in 2007 among the states and the federal government, must California start cutting back. That would be when Meat drops to an elevation of 1,045 feet. As of mid-November, it was at 1,112 feet.
Arizona has also been taking steps. Farms, where half of Arizona’s water from the Colorado River goes, have fallowed 10 percent of their acreage. Reductions have been a “hard sell,” said Ticknor. “People are having a hard time grappling with the size of the reductions and the nature of the impacts.”
Asked at the forum sponsored by the Colorado River Water Conservation District in Grand Junction, Colo., about the willingness to reduce water use for parks, golf courses and other urban greenery, she answered: “Those conversations are ongoing.”
Drought has usually been blamed for the declining reservoir levels. But upper basin states have released 8.23 million acre-feet in all but one year in this century from Lake Powell, located higher in the drainage.
Far more than drought is at work. There’s also something called the “structural deficit.” This water-wonkish phrase is used by Colorado River experts to describe the fact that more is expected of the river than it can possibly deliver. When delegates from the seven basin states assembled in Santa Fe in 1922 to apportion the river’s waters, they assumed 18 million acre-feet. It has rarely delivered that much since then. This century, there’s been much less. Flows in the river since 2005 have averaged 12.7 million acre-feet.
Variability is a given. That’s essentially what the river’s two giant reservoirs, Mead and Powell, were created to moderate. There will be dry years. Framers of the Colorado River compact understand that.
Drought isn’t the real problem here. The real problem, said Ticknor, is “the simple fact that the lower basin (Arizona, California and Nevada) uses 1.2 million acre-feet more water than is delivered.”
Change disguised as drought
Warming temperatures can create the impression of drought. Since 2000, precipitation in the basin has been more or less average. However, all years have been warmer than average, said Jeff Lukas, of the Western Water Assessment in Boulder, Colo.
In Western Colorado, which provides half the water of the river, temperatures have increased about 2 degrees Fahrenheit in the last 30 years. Summer temperatures have spiked even more, nearly 3 degrees F.
Models suggested a degree warming in the basin could produce a 5 to 10 percent reduction in Colorado River flows. Particularly hot years, including 2012, have reduced flows 20 percent. A growing body of evidence compiled by researchers points very strongly if still circumstantially toward rising temperatures as the primary cause for reduced flows.
In a later interview, Lukas explained that this is not new to researchers, who for at least a decade have been linking increased temperatures with reduced flows. But he also pointed to a multitude of factors that influence runoff in any given years.
“We have giant beetle infestations in the headwaters of the Colorado. We have dust on snow events. We have wildfires. We have just crazy variability in our weather, with a ton of snow during one May and another May really dry,” he says. There is great complexity, he adds, between how much snowfalls and the runoff in the Colorado River.
Despite this great variability, which scientists call noise, researchers believe they see a clear effect of climate change as predicted by models.
“It’s a really noisy system with a lot of different factors, but I think we are starting to see the warming signal emerge – now and not just 30, 50 or 70 years out,” says Lukas.
Lukas points out that much of the infrastructure and many of the water management policies are predicated on the climate of the 20th century, when we made dams and other decisions about how to manage our natural resources.
“And the climate was roughly 2 degrees cooler than it is in the Western Colorado than it has been in the 21st century,” he says.
More blunt yet in his assessment was Abrahm Lustgarten, a writer for ProPublica, a non-profit journalism foundation, who spent two years researching the Colorado River issues. Western water use amounts to “wishful thinking that there is more water than there actually exists,” he said in a noon-hour speech at the forum. “This is a fundamental untruth.”
Lustgarten zeroed in on cotton farming in Arizona. He told of one cotton farmer in central Arizona who has 8,000 acres. Each acre of cotton requires six times as much water as an acre of lettuce, and 60 times as much as wheat. Why grow cotton? The price is low, because of a world-wide surplus.
The farmer grows cotton, he said, partly out of habit, partly from pride—but also because of federal incentives. In Arizona and California, $4 billion has been doled out by the federal government to cotton farmers.
In a pinch, can water be diverted from farms to cities? Cities from Denver to Los Angeles have been participating in a basin-wide study that is seeking to study how savings can be wrung from farms and industrial uses, if necessary.
One such project is near Hotchkiss, along the North Fork of the Gunnison River in Colorado. There, Tom Kay, of North Fork Organics has voluntarily participated in a program begin underwritten by Denver Water, the Central Arizona project and other water agencies, but also The Nature Conservancy and Trout Unlimited.
Those organizations are providing money for Kay and other farmers to plant crops crops that need less water. We’re using one acre-foot per acre instead of three acre-feet, and they’re compensating the farmer for the two-acre-feet not used,” explained Kay at the forum in Grand Junction. A side benefit for Kay is that he has been able to transform production to certified organic, with a significant increase in pay.
The program is half-way through a four-year trial, but results have been dramatic. “When you go from furrow flooding to field sprinklers, you can get by with a half or a quarter of the water,” said Dave Kanzer, chief deputy engineer for the Colorado River Water Conservation District.
As general manger of the Colorado River Water Conservation District, Eric Kuhn has been warning of the influence of global warming in the basin for a decade. He is also a proponent of practical politics.
After the searing drought of the early century, the U.S. Department of Interior guided creation of a protocol for sharing shortages not anticipated by the 1927 compact. Adopted in 2007, the interim shortage criteria set the course for the reductions now being instituted in Arizona and those ahead for California.
More will almost certainly be necessary, as a new report from the Getches-Wilkinson Center at the University of Colorado has advised.
Bottled water for Colorado Springs?
“Sixteen years of drought had continued overdraft of supplies have taken their toll on its major reservoirs and have stressed operational protocols, and climate change threatens further reduction to runoff,” he says. “Lake levels are hovering around the elevation at which the first-ever shortage declaration on the river must be announced by the secretary of Interior. The declaration could come as soon as August 2017.”
Kuhn, who was one of 65 “thought leaders” interviewed for the report, says the states need to come up with solutions, which inevitably entail compromises. “We have to make some decisions, and we are not gong to get what we want, but we are not going to push ourselves over the cliff, either,” he said. Letting the courts sort out how to respond to shortages is “too risky,” he said.
While much has been made of the lower-basin living beyond its means with over-drafts of the Colorado River, Kuhn said that Colorado itself is not immune. The 1948 upper-basin compact apportions 51.75 percent of Colorado River flows upstream of Lee’s Ferry to Colorado, But in this century, he said, Colorado has been taking 58 percent.
Kuhn also stressed political realities. Cities tend to have junior water rights, but turning off their spigots isn’t going to happen.
“No governor of any state, of any political part, or either gender is going to turn off water to people, especially big cities,” he said. “If you have a town of 100, you can send them bottled water. But you aren’t going to meet the needs of Colorado Springs with bottled water.”
A crisis in the Colorado River? That’s the easy story, and without action it’d be the accurate story. The more nuanced story is one of changes underway and more yet to come—because, after all, the climate does seem to be shifting.