How Much Water Does a Cow Need?

By Claire Hamlett

Some good news for California. The federal agency NOAA reports that a winter of heavy rains brought some relief as much of the state is no longer in extreme drought. But predictions aren’t entirely rosy. Researchers warn Oregon and Texas still face severe weather this spring, putting millions of animals at risk.

How much water does a cow drink each day anyway? That’s only part of the equation, it turns out. The amount of meat and milk we eat in the U.S. requires a whole lot of water — more than 72 billion gallons per year according to University of Nebraska scientists. It’s not just what the animal drinks, though each 1200 pound cow needs around 12 gallons every day — and twice that for a lactating dairy cow — but it’s the thirsty feed crops that are the real culprit, especially alfalfa.

Crops to Feed Beef and Dairy Cows Are Sucking Up Water Across the U.S.

Twenty-six million acres of alfalfa are grown and cut for hay in the U.S each year, particularly in the western U.S. According to a 2020 Nature Sustainability study, across the 17 western states where production is concentrated, alfalfa accounts for a whopping 20 percent of all river water consumption, making it the biggest recipient of water in the western region.

Still, the U.S is exporting increasing amounts of feed crops too — particularly to China where demand for meat is on the rise. In 2021, alfalfa hay exports reached a record of 2.86 million metric tons.

Most of the alfalfa and other feed crops go to feed beef. According to the Nature study, a whopping two-thirds of these crops grown in the western U.S. are used to produce this red meat, with the remaining third going to dairy cows. In the U.S., 95 percent of cattle is fattened on grain, silage and hay for the last 160 to 180 days of their lives — which amounts to around 25 to 30 percent of their lifespan. Most dairy cows, by contrast, spend their whole lives indoors or in feedlots, fed a mix of grasses and irrigated crops such as alfalfa, corn and soy.

Climate Costs of Beef and Dairy in a Drought 

Feed crops are not the only reason these farms are so water-intensive. The beef and dairy industries also use a lot of water directly, though this accounts for a much smaller proportion of their overall water use. In both the western states and the U.S. as a whole, just watering livestock accounts for 2 percent of overall water consumption. 

Much of the U.S. – including parts of California — are still in drought, and will continue to experience a dry spring and summer. It’s clear the amount of milk and meat in our diets puts a massive strain on water use and drives climate emissions.