March 4, 2020

 

US beef demand sucks Western rivers dry

 

 

New research shows that across the western US, a third of all consumed river water goes to irrigate crops not for human consumption, but for feeding beef and dairy cattle.

 

In some western river basins, such as the Colorado River basin, over 50% of the water goes to cattle feed and fodder for cows.

 

The burgers, steaks, yoghurt and ice cream Americans eat in abundance, the new results show, is directly related to the overuse of river water—leaving the ecosystems and communities that depend on those rivers drastically stressed under even the best of circumstances. During bad drought years, the stress ratchets up on many western rivers, nudging over 50 species of fish closer to extinction or imperilment, according to a study.

 

The good news, says Brian Richter, the lead author of the study and a water expert at Sustainable Waters, is that the detailed tracing they have done gives growers, policy-makers and consumers a lot of power to make different choices.

 

"We could see the water being pulled out of a specific river, going to a specific feedlot or dairy, and then as a product going to a specific place where it was consumed," he says. That kind of detail can be leveraged to make very targeted changes that could save vast amounts of water.

 

Richter and his colleagues tracked the water taken out of rivers and streams in each little fraction of a watershed to the places it was being used to irrigate crops, and in many cases could trace its journey to farms or counties that grew certain cattle feed crops. Then, they could use economic data about supply chains to trace the journey of those crops from farm to feedlot, and from feedlot to the place the beef or dairy products were ultimately sold.

 

They could also estimate how much the water withdrawals from individual watersheds would endanger fish populations living in those delicate waters. Low summer water flows in rivers across the region, particularly when caused by water extractions that end up irrigating cattle feed crops, have added to the local extinction risk faced by nearly 700 species of fish.

 

"The summer—that's the growth season for many species of fish, when the water is needed the most," says Marguerite Xenopolous, an aquatic ecologist at Trent University in Ontario. "When water is taken out of the river, and it's tied to some aspects of species life cycles of the fish, they can be particularly hard hit."

 

Overall, the beef grown with crucial river water supplies was eventually routed mostly to major urban areas in the West: Los Angeles and Long Beach and the Bay Area of California; Portland, Oregon; Denver, Colorado; and Seattle, Washington. If they broke it down per capita, Oregon, Idaho, and some hotspots in Texas ate the most beef associated with river water depletion.

 

Some 23 million acres of alfalfa are grown across the US. The plant was ferried west during the Gold Rush of the 1850s, when it was a crucial feed source for the cows, horses and other grazing animals that settlers relied on for food and labour. Beef cattle and dairy industries expanded across the western US over subsequent decades, but the animals needed more feed than they could forage from the dry landscapes—so feed crops like alfalfa became more and more critical to the burgeoning herds. As large-scale irrigation projects bloomed across the west, more and more cattle-feed crops could be grown, supporting ever-expanding herds.

 

"It's an amazingly adaptable crop," says Brad Udall, a climate and water expert at Colorado State University. "It'll grow from hottest desert to highest mountain, and get you multiple cuttings a year, and it's pretty easy to grow."

 

In the Colorado River, which supplies water to over 40 million people and thousands of industrial users across the West, the average flow is down 17% a year compared to the 20th century average. Up to half of that missing flow is driven by human-caused climate change, Udall says.

 

Last week, a team published a paper in science showing that the Colorado's flow is projected to diminish another 20% to 30% by the middle of the century, ratcheting up the pressure on every single user of the river water and intensifying the need to develop new, innovative solutions. Currently, the seven states that rely on Colorado River water are discussing ways to reduce their usage, both to deal with the fact that the river has been significantly overdrawn for years and to come up with a plan to adapt to a drier future.