Hay grown for cattle consumes nearly half the water drawn from Colorado River, study finds

Ian James | (TNS) Los Angeles Times

With chronic water shortages afflicting the Colorado River, discussions about how to cut usage have increasingly focused on a thirsty crop that consumes an especially large share of the river’s water: hay that is grown to feed cattle and produce beef and dairy products.

In a new study, researchers found that alfalfa and other cattle-feed crops consume 46% of the water that is diverted from the river, accounting for nearly two-thirds of agricultural water use. The research also shows that agriculture is the dominant user of Colorado River water, accounting for 74% of the water that is diverted — about three times the combined usage of all the cities that depend on the river.

The study presents the most detailed analysis of its kind to date, including extensive data on where the river’s water goes across seven Western states and northern Mexico. The research sheds new light on how the river’s water is used at a time when representatives of the federal government, states and tribes are seeking long-term solutions to reduce water use and adapt to climate change.

“It’s important to understand where all of the water goes,” said Brian Richter, a researcher who led the study. “This is the first complete and detailed accounting.”

Richter said he hopes the findings will provide vital information for ongoing talks that will determine “what we want the future of the Colorado River to look like.”

The study, which involved a team of 12 researchers and was published in the journal Communications Earth & Environment, expands on previous research by including water use data for Mexico; the Gila River, a major tributary in Arizona; and supplies that are transported through canals and pipelines to areas outside the Colorado River Basin.

The researchers analyzed all water diversions for agriculture, communities and industries from 2000 to 2019, and calculated annual averages. They also included estimates of how much water evaporates from the river’s reservoirs, and the uptake of water by vegetation in wetlands and riparian areas along the river. Together, those account for 30% of overall consumption.

When additional losses that occur naturally along the river are factored in, agriculture accounts for 52% of overall consumption, including 32% of the total that goes toward irrigating alfalfa and other types of grass hay.

Cities — including municipal, commercial and industrial water use — account for the remaining 18% of overall water consumption.

The Colorado River supplies cities and farmlands in seven states from Wyoming to California, as well as 30 tribal nations. For decades, so much water has been diverted that the river has seldom met the sea and its once-vast wetlands in the river’s delta have dried up.

The river’s flow has declined dramatically since 2000, and research has shown that global warming worsened the long stretch of extremely dry years through 2022.

The river’s largest reservoirs, Lake Mead and Lake Powell, remain at low levels despite a series of water-saving agreements, and the region’s water managers have been engaged in difficult negotiations on new rules for dealing with shortages after 2026, when the current rules expire.

“We need to move out of a reactive mode and into a proactive mode for the long term,” said Richter, who is president of the organization Sustainable Waters and senior freshwater fellow for the World Wildlife Fund.

Richter noted that with agriculture using much of the water, there has been increasing attention focused on ways of achieving reductions in usage, and he said the research can help by detailing how much is going to different crops, such as hay, wheat, cotton and vegetables.

Over the last two decades, many cities in the Colorado River Basin have made progress in conserving water. In another study, Richter surveyed 28 urban water utilities and found that total water use dropped by 18% between 2000 and 2020, even as the population grew by 24%.

“The cities that depend upon the Colorado River are doing a miraculous job of reducing their needs for that water, and we now need to see a commensurate reduction in agriculture’s use of the river,” Richter said.

“We need to get very serious about shifting to a different mixture of crops, and we need to reduce the overall footprint, the acreage of land, that is being used for farmland,” Richter said.

Alfalfa and other types of hay are especially water-intensive crops. In one report, Richter and other researchers compared the estimated water demands of different crops and found that alfalfa requires significantly more water per acre than cotton, corn or wheat.

Richter said the purpose of the research isn’t to point fingers at farmers for the crops they choose to grow, but rather to show where opportunities lie for switching crops and transforming agriculture in the Southwest.

“It’s important to acknowledge that farmers are growing what people want and are willing to pay for. And the reason we’re using so much of the Colorado River water to feed cows is because of our demand for beef and dairy products,” he said. “And our demand for dairy, and specifically cheese, has been going up, which is causing expansion of dairies in a lot of the West and in the Colorado River Basin, and so that’s why they’re growing so much alfalfa.”

Richter said that as a scientist, he is reluctant to tell people what to eat, and thinks everyone should “act on their conscience.”

“Personally, once I started this research, I gave up beef consumption altogether,” Richter said.

The study found regional differences in the Colorado River Basin, where the water irrigates more than 5 million acres of farmland and ranchland.

In the upper basin states — Colorado, Wyoming, Utah and New Mexico — cattle-feed crops consumed 90% of all water used by irrigated agriculture on average. In the lower basin states of California, Arizona and Nevada, hay accounted for 57% of agricultural water use, with more water going to crops such as wheat, cotton, oranges, lettuce and broccoli.

The researchers noted in the study that alfalfa is also attractive to growers for other reasons, including its hardiness and ability to survive with less water during droughts and then come back quickly once full irrigation resumes — functioning like a “shock absorber” for farmers dealing with unpredictable conditions.

Richter and other researchers have estimated that two-thirds of the alfalfa and other hay are used for beef cattle while the remaining third is used for dairy production.

Much of the hay is used to feed cows locally or in nearby states. But increasing amounts of hay have also been exported in recent years to countries such as China and Saudi Arabia. In one study, researchers at the University of Arizona examined crop data for seven Western states and estimated that 20% of the region’s total alfalfa production was exported in 2022.