Note to readers • This article is published through the Colorado River Collaborative, a solutions journalism initiative supported by the Janet Quinney Lawson Institute for Land, Water, and Air at Utah State University.
Water is precious to Dwight Brinkerhoff. Over the decades he’s farmed in Wayne County, the goal has been to stretch water supplies.
“It is the resource that we have,” he said, “that if we did not have, we would not be here.”
Farms in this southern Utah valley were irrigated by flooding when he was young, he said. Now, some of his neighbors have high-tech automated sprayers. And the next evolution might be taking shape in one of his own alfalfa fields.
That’s where Utah State University researcher Maziyar Vaez Roudbari stood spinning the head of a new rotator sprinkler — a brightly colored plastic nozzle roughly the size of a soda can.
He’s testing a potential replacement for the traditional sprinkler heads on Brinkerhoff’s wheel line irrigation system. The rotator throws water in uniform droplets, Roudbari said, so it should help more moisture reach the soil rather than getting lost in the wind.
“Ultimately, our goal is [to] identify a sprinkler system to provide the best balance of water conservation and crop health,” he said.
Roudbari’s team has installed around 250 test sprinklers like this on farms and research plots across Utah to see their real-world performance.
If the project works, it could help farmers put more water where they want it without having to replace their whole irrigation system. That would be especially important in Wayne County, which relies on the increasingly strained Colorado River system.
“The river faces ever more pressure from overuse, climate change and drought,” Roudbari said. “More efficient irrigation could help reduce water demand by providing farmers more tools to conserve water without sacrificing crop yields.”
(David Condos |KUER) Dwight Brinkerhoff flicks the spring-loaded arm of a brass impact sprinkler at his farm in Wayne County, Aug. 22, 2024. Replacing traditional sprayers like this with new water-efficient versions may boost crop production but is unlikely to have a significant impact on saving the Colorado River.
Who will efficiency help?
Agriculture is Utah’s biggest water user. So, many proposals to save the shrinking river depend on finding ways for farmers to cut back. The state has set aside $276 million to help modernize sprinklers and canals. Some farmers are testing out alternative crops that may use less water than the state’s top crop, alfalfa.
Utah also launched a program to pay farmers to leave fields temporarily unplanted and unirrigated, a practice known as fallowing.
Many of the efforts — from the state’s big-money modernization program to the nozzle test in Wayne County — aim to use water more efficiently. It’s not clear, however, how big of a dent that can make when it comes to boosting Colorado River levels.
It can even do the opposite, said Burdette Barker, an assistant professor of irrigation at USU.
“It is kind of, in a way, the wicked problem of water efficiency,” Barker said. “For quite a long time in the irrigation science and engineering world, it’s been understood that in general — so, not every case, but in general — when we improve efficiency, we increase consumptive water use.”
If you feel like that sounds paradoxical, you’re not alone. Frank Ward, an agricultural economist at New Mexico State University didn’t believe it at first. To him, “it didn’t quite seem plausible.”
Higher efficiency means a larger percentage of the applied water makes it to the plant roots, which is good for crop yields. Ward and his colleagues have found in their research, however, that installing more efficient irrigation does not automatically mean saving water. It simply changes where the water goes.
“Drip irrigation and center pivots are good things to do,” Ward said. “They promote the goal of lower food prices, higher food production and farm income, if they’re subsidized. Just don’t call it investments in water conservation.”
That’s because of the difference between water use and consumptive water use. For water to be considered consumed or depleted, it needs to be removed from a river basin.
Let’s say you have a farm with an old wheel line sprinkler system where 70% of the water you draw ends up in your crops. Some of the remaining 30% then seeps into groundwater or runs into streams. As far as the river basin is concerned, that leftover water wasn’t depleted because it stayed in the watershed.
If you upgrade to a new 95% efficient irrigation system, a lot more water is consumed by your crops and a lot less runs off back into the local water supply.
That may work economically, but not hydrologically, said Zohrab Samani, a NMSU professor who has researched farm water use along with Ward.
“Efficient systems are good for the farmers because they maximize the profit from the unit of water they use,” he said. “But nothing goes back to the reserve.”
(David Condos | KUER) Utah farms commonly use wheel line irrigation systems, like the one seen here in Wayne County, Aug. 22, 2024. Making these sprinklers more water-efficient may help farms produce more crops, but that doesn’t mean it would save more water for the Colorado River.
The possible trade-off ahead
Farms are where our food comes from, Samani said, so supporting agricultural producers and communities is a worthwhile investment. But government agencies need to balance the positive economic impacts of subsidizing new irrigation equipment against the potentially negative hydrologic impacts.
As states across the West look to irrigation efficiency as a conservation solution, it’s been a challenge for Ward and Samani to get this message to sink in. The federal government set aside hundreds of millions for similar programs to help conserve agricultural water in 2024.
Other example projects would be lining a leaky irrigation canal with concrete or converting an open ditch into a pipe. Half of the $30 million in Utah’s 2025 agricultural optimization funding is set aside for these types of fixes.
Because a lot of the water leaking from a canal trickles back into the local water supply, Barker said, it isn’t really depleted. So, improving that type of inefficiency has a limited impact on the river.
“Piping projects don’t really reduce this consumptive water use. What they do do is give the canal operators more control of the water,” he said. “So, I don’t want to make it seem like these projects are not beneficial, but they don’t immediately make water available in the basin.”
Improved efficiency has other benefits, Barker noted. It can control weeds and pests. It may also improve water quality, since runoff from inefficient systems can carry salt from underground deposits or nitrate from fertilizer when it returns to the water supply.
It could also help Utah grow more food per gallon of water by cutting down on evaporation, a common form of depletion.
Barker said more pilot programs, such as the Wayne County nozzle test and a Colorado River Authority of Utah subsurface drip project in northeast Utah, can help us understand how different tools work in practice. Showing Utah farmers which options can squeeze the best possible harvests from their water could help sustain them in a drier future when there may be mandatory cuts.
At some point, however, better efficiency would need to be paired with other Colorado River conservation efforts that reduce the total amount of water Utah agriculture consumes.
That could mean farmers shortening their growing season — say, three months of irrigation instead of six — or reducing the acres they water. Switching to crops like wheat or oats that require less irrigation than alfalfa could help, Barker said, but those crops aren’t as profitable.
If the goal is to save Colorado River water, that’s a trade-off Western leaders may need to take.
This story was produced as part of the Colorado River Collaborative. KSL TV photographer Mark Wetzel contributed to this story.
