GRAND COUNTY — In the middle of 300 acres of picturesque hay meadows just north of Kremmling, not far from the headwaters of the Colorado River, a metal pillar surrounded by fencing rises 10 feet from the ground. It looks something like a miniature cellphone tower with various technical instruments and antennas jutting out at the top.
This tower, one of only a few scattered around the state, and the only one situated on the kind of high-altitude pasture land that’s plentiful across Colorado, counts water down to the molecule as it evaporates off the ground. The tower has been positioned in this field for the past two years as part of an ongoing study. It is providing farmers and researchers with critical information about how much water Colorado agriculture could potentially conserve in the drought-stricken West.
“Bare bones, it’s a huge inventory-taking process,” said Perry Cabot, a water resources specialist and research scientist at Colorado State University who is part of the team conducting the studies in these Kremmling fields. “How much water is being lost from these farms? Even under the best-case scenarios, knowing this inventory gives us an ability to put some realities around what role can Colorado actually play in solving this structural deficit.”
On the Colorado River, where demands far outpace the water supply, the deficit is significant. Recently, the commissioner for the Bureau of Reclamation Camille Touton testified to the U.S. Senate Committee on Energy and Natural Resources that water users in the seven states that rely on the river must cut between 2 million and 4 million acre-feet to prevent the system from reaching “critically low water levels” by the end of 2023. The Colorado River supplies drinking water to more than 40 million people and farmers use it to irrigate millions of acres of farmland. (An acre-foot is the amount it takes to cover an acre in a foot of water, or about 325,000 gallons.)
In Colorado, agriculture diverts about 85% of the water statewide, according to the Colorado Department of Water Resources, which often makes the industry a focal point of any discussion of large-scale water conservation. During the past few years, pilot programs have attempted to probe how reducing irrigation on farmland through voluntary, temporary and compensated measures could help conserve water. That water that could then potentially be moved around and used elsewhere.
But, Cabot said, there’s been a lack of key data central to arranging any kind of water-sharing agreement: If a farmer doesn’t irrigate a field, how much water is actually available to be transferred? At the moment, Cabot said, the answer is not particularly well understood on fields above roughly 6,500 feet.
“No one else has high-elevation pasture data for what is arguably the most dominant form of agriculture in Western Colorado,” he said.
Cabot said it’s essential to learn in as much detail as possible how much water is lost from these fields through evapotranspiration — a term that collectively refers to evaporation off the ground and transpiration from plants. “Not irrigating will not reduce this field to zero consumptive use,” he said. “What we want to know is what is the amount of consumptive use that is conserved by the action of not irrigating.”
This fancy, $50,000 water-molecule-counting tower should provide about as good of an understanding as technology currently allows. “As far as water-counting towers go,” Cabot said, “this is the Cadillac.”
Chicken and egg
Known as the Upper Colorado Conservation Project, this research study launched in the summer of 2020, includes about a dozen partners in Colorado and Utah and is funded by multiple grants. Pulling together any group that size can be challenging. At one point early on, though, the prospects for getting the whole thing off the ground hinged on a couple of farmers sipping Budweisers, having a heart to heart.
The idea grew from discussions during the Colorado Basin Roundtable, one of nine regional water workgroups started by the legislature in 2005. Cabot expressed the need for this type of research on high-elevation farmland. Paul Bruchez, a fifth generation Kremmling rancher and the Colorado Water Conservation Board member who represents the main stem of the Colorado River, participated in the roundtable. Bruchez agreed to try to wrangle some landowners for the kind of research Cabot wanted to conduct. “If Perry needs a high-altitude study, I’m the guy in the room who has the high-altitude neighbor friends,” Bruchez said.
The catch was that signing up meant agreeing to not irrigate a chunk of acreage in 2020. During the study’s first year, the idea was to research evapotranspiration on dried up fields and then in subsequent years examine how production on those fields recovered. The problem with getting it all started, Bruchez said, was a chicken-and-egg sort of thing. Bruchez needed ranchers to sign on so that the research group could ask for money, but he needed money to pay the ranchers to get involved. “How do you ask people to participate if you don’t have any money?” Bruchez said.
He started by sitting down with his family and seeing if he could get them to agree to fallow enough acreage to apply for a grant. Cabot wanted between 500 and 1,500 acres for the study. Bruchez’s family was in. With that commitment, the project team got some money, and then Bruchez approached his neighbors. He recalls having a beer with the guy in charge at the farm that would end up becoming the study’s largest participating landowner. The guy wanted to know why Bruchez was motivated to do this.
“When that family agreed,” Bruchez said, “I was sitting there drinking a Budweiser, and he said ‘I want my grandchildren to have the opportunity to be ag producers and have the opportunity to do what I do.’” Bruchez responded that he wanted the same thing and that he thought this research could help in the long run. “He was in,” Bruchez said.
In the end, nine landowners, including Bruchez, signed up, agreeing to dry up about 1,100 acres in 2020 and to cut off irrigation early — no watering after June 15 — on another 200 acres, what’s known as deficit irrigation.
“Look, none of us want to dry out our hay meadows,” Bruchez said. “But there are benefits to us locally and to ag in general in our state of understanding this kind of science.”
The crux
In late June, the conservation project team reported some initial results from its first year of research. On average, when compared to the amount of water consumed on these fields during the spring and summer from 2016 through 2019, as well as a nearby reference field in 2020, halting irrigation resulted in about 42% less water lost through evapotranspiration.
The researchers arrived at that number by using data from the Cadillac water-counting tower and then gauging those numbers against a satellite capturing similar data via a method called remote sensing. The idea is that the in-field tower provides a high quality “ground truth” that the satellite data can be checked against. If the remote-sensing satellite matches closely enough the information registered at the tower — as was the case in these fields — researchers can then confidently use the satellite on its own to gather evapotranspiration data on a larger scale.
So, not irrigating a Kremmling hay meadow for one year could save 42% of the water, the program’s preliminary findings show. In theory, that amount of water would remain in a reservoir somewhere, and, again, in theory, could be used some other way, say, to benefit environmental streamflows, somehow be transferred to and used by a city, or possibly help raise water levels at Lake Powell. How exactly that water might be moved, a process known as shepherding, presents another set of challenges not addressed in this study.
Bruchez cautioned that 42% was an average across all 1,100 acres. In some spots, he said, the water savings was much higher. “You can’t say drying up high-altitude ag saves 42% of water,” Bruchez said. Regardless of what the number is in what corner of which field, Cabot said that 42% is a good starting spot for a discussion about possibly paying a farmer to save water on this kind of agricultural land.
“I think we’re getting to the point where you could say this is a pretty reliable estimate on reduction of consumptive use that would occur from a farm that doesn’t irrigate,” Cabot said. “That’s the crux of the project.”
Aaron Derwingson, water projects director for the Colorado River Program at The Nature Conservancy, a partner in this conservation project, said Commissioner Touton’s startling assessment of the Colorado River only heightens the significance of this work. “When the bureau says you have to save 2 to 4 million acre-feet and you have two months to do it, all eyes are going to ag,” Derwingson said. “If we’re not ready with ideas and potential solutions and opportunities, then what could come down from up top would not be the best for ag and the best for the environment.”
Researchers will monitor these fields through at least the end of next year, continuing to gather data from the tower and remote sensing methods. Part of the additional focus now is understanding how productive a field will be in the years after halting irrigation. “Anyone that has a lawn knows this,” Cabot said. “If you don’t irrigate a lawn you won’t have a very nice lawn next year.”
The numbers aren’t finalized, Bruchez said, but some fields seem to have fully bounced back while others are only up to about 70% of normal production. Understanding the extended impact to a field and the economics of that impact is critical for farmers, Bruchez said.
“For me being an ag guy, it’s relatively reasonable to punch a calculator on your losses in any given year from yield and production,” he said. “But it’s the recovery of those meadows … it’s the aftermath.” Not surprisingly, Bruchez said, it appears the fields planted with more drought-resistant perennials have rebounded more quickly.
The study will continue to examine what forage types appear to grow better under drought conditions or recover faster after a field has been fallowed. Derwingson is excited about this part of the project. “I think we’ve been operating on this assumption that we have time, we have an opportunity where we can rotate water conservation around to use less water on a temporary basis and get through these rough patches,” he said. “I think what we’re seeing now is we probably need something a lot more than that.”
Whether it’s some kind of voluntary compensated program or involuntary because the situation on the Colorado River has become dire enough that officials are curtailing water use, “water conservation is going to become an inevitable reality,” Bruchez said. Across the entire Upper Colorado River Basin — not just in Colorado — agriculture historically since the mid-’80s has used roughly 65% of the water, Bureau of Reclamation figures show. About 20%, according to the BOR, goes to transmountain exports.
“Let’s figure it out so people can have a heads up about what life is going to look like,” Bruchez said.
Once completed, Derwingson said the Kremmling study should help water managers be strategic about how best to consider conserving agricultural water. “You can’t manage what you can’t measure,” he said. “We’re facing this huge water management challenge — we have to know what we’re using and what we might be able to save.”