气候变化领域集成服务门户

And thanks to research mandated by the 1992 Grand Canyon Protection Act, the fate of the chub and the canyon ecology are factors that will also need to be considered in the yet-to-be-scheduled negotiations. Ultimately, everyone's worried about losing their share of the Colorado River, of going home with partly empty buckets because there's just not enough water to go around.

"The pie is getting smaller," said Jack Schmidt, director of the Utah State University's Center for Colorado River Studies, noting that more users sharing less water increases pressure to revamp water agreements.

To understand what he means, here's a quick primer on Colorado River allocations beginning with the term "acre feet." It's roughly the water needed to fill a football field a foot deep or about 326,000 gallons.

Under original agreements, including the Colorado River Compact, Schmidt's "pie" amounted to 17.5 million acre feet of water, which has proven to be an overestimation of "average" flows because the calculation was made when the river was unusually full. So over the last two decades, thanks in part to climate change and drought, the size of that pie has shrunk to an average annual flow of about 12.5 million acre feet. In short, the pie is about one-third smaller on average than when water users divvied up the river.

"People have to come to terms with the fact that they can't keep the size of that [accustomed] slice when the whole pie is getting smaller," said Schmidt.

Having once led the humpback chub "alien abductions" and the rest of the scientific program at the U.S. Geological Survey's Grand Canyon Monitoring and Research Center, Schmidt is now studying how climate change might affect not just the endangered fish species and the basin environment overall but also traditional river flows and hydropower output. And, although he says environmental concerns in the canyon typically have been "an afterthought" in how the river is managed, he hopes the research becomes central during upcoming negotiations.

Opportunities to tinker with river management plans are coming up fast.

The U.S. Interior Department must begin updating plans for managing the river, and convene all the states that rely on it, by the end of the year under the Colorado River Interim Guidelines, one of the agreements that determine how much water is allocated for each stakeholder to use or develop.

Like everything about Colorado River management, it's legally complex and controlled by a deeply entrenched power structure involving the seven basin states, the federal Bureau of Reclamation and established users in agriculture and municipalities that have assigned positions in the line to the spigot—spots known as "water rights." Dry as it might sound, it's dramatic stuff, grist for a neo-noir thriller like the 1974 film, Chinatown.

But even the guidelines, which were implemented in 2007, have fallen short in the new, drier West. Last year, Congress approved a pair of Drought Contingency Plans, requiring varying levels of conservation to be implemented, state-by-state, whenever water levels sank too low at Lake Powell or Lake Mead, the ginormous storage reservoirs for Colorado River water. Both lakes dropped to emergency levels within months.

The original compact guarantees certain water volumes to the lower basin states—Arizona, Nevada and California.  The upper basin states—Wyoming, Utah, Colorado and New Mexico—historically haven't used all of their allocations but plan to develop theirs, too. For example, Utah is pressing forward with a multibillion-dollar project to pipe 86,000 acre feet halfway across the state to the fast-growing southwestern part of the state. A diversion of water from the Utah-Wyoming border to Colorado's populous Front Range—killed and resurrected so many times it's called the  "zombie pipeline"—would use 55,000 acre feet.

Still, Schmidt said: "I am actually very hopeful. I believe that climate change and the real need to renegotiate agreements have brought us together."

The role of global warming as a motivator for revisiting the water allocations probably can't be overstated. The average temperature in the Southwest has already risen twice as fast as the global average and future temperatures are projected to increase as much as 9.5 degrees Fahrenheit by 2100.

Climate change is just one reason Daryl Vigil, water director for the Jicarilla Apache Nation and interim director of the Ten Tribes Partnership, is determined to see tribes at the table in the next round of negotiations. He says the 29 basin tribes have priority rights to about 20 percent of the Colorado River's water but were snubbed by current users from past Colorado River talks.

"The system is going to protect itself, to perpetuate what it already does because it benefits those who already are doing okay," he said. "Familiar story, right?"

The exclusion, which amounts to environmental racism, means tens of thousands of indigenous people have not been able to access their water and tap into the associated economic opportunities, such as selling their water rights and using the water for energy projects, he said. Instead, other stakeholders are using tribal water without paying for it. 

Another reason the tribes should be part of the decision making, he said, is because of their experience—thousands of years of dealing with water scarcity in the region—and their cultural views about the environment belong in any critical conversations about the Colorado. Otherwise the future looks "pretty catastrophic to us," Vigil told High Country News this spring.

"When we start talking about climate change," he said, "absolutely pushing to make sure that we're thinking about a mindset of how we fit into Nature, rather than Nature fitting into us."

The humpback chub helps illustrate Vigil's point that water is living, that the river basin is more than a plumbing system.

Preserving the chub's DNA—and data about what's enabled the fish to survive 3 to 5 million years of life in the Basin—did not become a priority until the 1992 Grand Canyon Protection Act. Experimental releases at Glen Canyon Dam, studies about predation, water chemistry, temperature changes and insects have helped revive populations, and now the U.S. Fish and Wildlife Service is proposing to downlist the humpback chub from endangered to threatened status.

The U.S. Geological Survey's Grand Canyon Research and Monitoring Center, directed by Scott VanderKooi, has led efforts to monitor environmental balance while dam operations continue to generate energy and regulate reservoir levels.

When the pandemic prompted the closure of the river to boating this spring, several scientific trips had to be scrapped or postponed, he explained. They included cultural resource monitoring, the juvenile humpback chub "abductions" and an important three-year test of ways to boost insect life along the river. 

"For short-term changes, we're missing some data," VanderKooi said. "But for looking at these longer-term trends, we're confident that we'll have enough information to determine whether or not the experiment was successful and whether we were able to instigate those changes in the aquatic ecosystem that we believe will occur by altering these flows."

Populations of humpback chub have stabilized in the Colorado River Basin, and earlier this year the U.S. Fish and Wildlife Service proposed changing the legal status from “endangered” to “threatened.” The fate of this species is tied to operations of the Glen Canyon Dam which irrigates 5.5 million acres of farmland and provides water to around 40 million people. Credit: U.S. Fish and Wildlife Service