Eating Us Dry: Cows, Water Scarcity, and How a Plant-Based Diet Helps

The prevailing mood of Earth, looking upon it as an orb in space, is blue. Blue, accented with curling white streaks. Blue, wrapped around misshapen bundles of green and brown. Blue, seeming to give off its own radiance. This blue is water, and life hinges upon it.

There doesn’t seem to be much to worry about, really. Water covers 70% of the Earth’s surface and remains a relative constant. When we drink water, for instance, we don’t destroy it. When we boil it to steam, it becomes vapor and rises to the air – only to return to liquid again.

So how is water scarcity an issue – and what can we do about it?

To start, look at your eating.

Global Water Scarcity

Of the 326 million trillion gallons of water on Earth, about 96.5% is salt water and brine in oceans, bays, and seas. We can’t really do much with that. An additional 1.75% is found in ice caps, glaciers, and permanent snow – not terribly useful either. Subtract another 0.9%, which is saline groundwater, and we’re left with less than 1% of water that is fresh and accessible for human use. Most of this exists as groundwater. Only a tiny fraction can be obtained from surface aquifers like rivers and lakes. 1

There is still enough fresh water on Earth to fulfill mostly every human need, only it is unevenly distributed. Some regions, like the Great Lakes, have enough fresh water for many times their populations. Others have little and are faced with daily choices. Shifting and unpredictable weather patterns, population growth and its demands on food supply, desertification of land, exhaustion of freshwater aquifers, and glacial melt linked to climate change all pose threats. According to a 2016 study by Mesfin Mekonnen and the late, great Arjen Y. Hoekstra, four billion people (66% of the world’s population) face severe water scarcity at least one month of the year. 2

We need to begin thinking globally about where our water resources are going. This starts by thinking personally.

Cows and Water Use

Rainwater services some human needs, but most people and communities rely at least in part on natural aquifers like lakes, rivers, and groundwater for their livelihoods. About 70% of all such freshwater withdrawals are used in agriculture. Industry and municipal use cover the other 30%. 3

Not all agricultural products are equally efficient in providing nutrition relative to their water appetite, however. Hoekstra developed a way of evaluating how much water is required to make the products we use every day: virtual water. This refers not to how much water is in a product, but how much it takes to bring it to you, the consumer, starting from the farm. 4

Beef: A Virtual Drain

An 8oz steak on your plate looks like, well, a steak. There seems to be nothing liquid about it, except maybe the juices. However, including irrigating feed crops, filling the trough, and cleaning the stables, it took 930 gallons to create the steak. 5 This is the product’s virtual water content: 23 standard bathtubs full of water! By contrast, 8 ounces of beans require 27 gallons – or 1/70th the water. 6

Why does beef require so much water?

  • Cows eat a lot before they produce any yield. There is much variation from place to place, and between farming methods, but a beef cow may consume over 18,000 lbs. of feed in its lifetime. All of this, whether pasture or grain, takes water to grow – as much as 800,000 gallons total for 440 lbs. of beef. 6,7
  • Additionally, a beef cow may drink 6,300 gallons and require 1,850 gallons for servicing. This is a lot of water but negligible compared to the massive “thirst” of cattle feed. 4 In fact, 98% of a cow’s water footprint is in its food. 8

Cows also have a poor conversion efficiency. This means beef and dairy’s nutritional benefits are hardly exceptional given the resources – such as water – they consume.

For instance, cereal crops like oats form a significant portion of the average beef cow’s feed. Beef requires an average of 236 gallons to produce 8g of protein. Now, say you were to obtain the protein directly from a cattle feed crop like oats. In this plant-based case, 8g protein would consume only 44 gallons. 5 That’s one-fifth as much water to obtain the same quantity of this vital nutrient, simply by going around the “middleman” who says “moo.”

Beef and “Blue” Water

While most of beef’s virtual water use is rainwater, a significant proportion is drawn from what we call “blue” water sources. These include lakes, rivers, and the ground.

This is important because blue water is finite in a given time and place, and its overuse creates scarcity. It’s also vital for enduring drought and meeting the fresh water needs of growing populations. Overreliance on blue water, primarily for agriculture, has caused Asia’s Aral Sea – once the world’s fourth largest lake – to vanish. It is also the reason the Colorado River, which carved the Grand Canyon, no longer reaches the sea. 4

On average, an 8oz steak uses about 35 gallons of “blue” water withdrawn from the surface or ground. 5 A cup of dry beans, by contrast, delivers 16g protein with a blue water footprint of just 8 gallons. 9,10 Replacing half of your beef consumption with beans would save 1,500 gallons of freshwater withdrawals each year.

If 1% of the population were to do the same, we’d save almost 5 billion gallons of “blue” water annually. 5 That’s enough to cover the annual at-home needs of 45,000 U.S. households. 11

What About Dairy Milk?

Cow’s milk has a lower water footprint per serving than beef, mostly because there is greater yield across the animal’s lifecycle. A dairy cow will produce on average 100,000 glasses of milk (240mL) in a lifetime; a beef cow, the equivalent beef of almost 900 8oz steaks. 7,12

Still, owing to the dairy cow’s feed requirements – 100 to 120lbs. of water-intensive feed per day during the lactation cycle – a glass of milk requires 56 gallons in water to produce. 5,13 Imagine a pantry closet stocked, top to bottom, with gallon-sized containers of H2O. That’s what your little cup of milk looks like in virtual water. A glass of plant-based milk, by contrast, may require one-quarter to one-third of this. 14,15

The Water Savings of a Plant-Based Diet

All this water adds up. According to Hoekstra’s research, 27% of humanity’s water footprint is in animal products. At-home use is just 4%. “This means that if people consider reducing their water footprint,” wrote Hoekstra, “they should look critically at their diet rather than their water use in the kitchen, bathroom, and garden.” 8

Let’s focus on cows, which represent more than half of the water footprint of the entire global livestock sector (beef, 33%; dairy, 19%). 8 As of 2017, the average American was consuming 55.6 lbs. of beef and 18 gallons of milk annually. 16,17 If you’re this person, swapping just half of your beef and dairy consumption for plant-based alternatives for a year could save 60,000 gallons of water. 7,14 This is enough to cover 10 years of daily showers, 37,500 toilet flushes, and 1,700 car washes.

Hoekstra estimated that moving toward not even a vegan, but a vegetarian diet could reduce your personal food-related water footprint by 36%. 8

Elmhurst Saves Water

A plant-based diet saves our vital water resources, plant milks included. Some, of course, are easier on water than others. Top of this list is certainly Elmhurst Milked Oats™ and its variations: unsweetened, single-serve, barista, and creamer.

A glass of oat milk may have as little as 1/18th the water footprint of a glass of dairy, which requires about 56 gallons. 5,14,15 Elmhurst’s contains 4g of protein – half as much as a serving of dairy milk. It also contains something dairy can’t deliver, no matter how many oats cows may consume: 20 g of whole grain. Measuring nutrition obtained per gallon of water used, oat beats dairy – no contest.

A similar comparison can be made for most plant-based foods compared to their animal alternatives. Wrote Hoekstra, “The water footprint of any animal product is larger than the water footprint of a wisely chosen crop product with equivalent nutritional value.” 8


We must care for ourselves, and plant-based foods help us do this. Still, it is important to have a reason for our behaviors that reaches beyond ourselves, perhaps even touching faraway corners of this deeply yet deceptively blue Earth.

Carbon emissions may be the headliner among environmental crises, but the depletion of freshwater resources is not far behind. Half a billion people are currently living with severe water scarcity year-round. 2 If you’re saving water – particularly surface or ground water – you’re helping relieve water stress; perhaps indirectly helping people living in extreme need.

If you’re still wondering what you can do, think about this. In 2012, global animal production was consuming 2,422 billion metric tons of water, more than the combined volume of Lakes Erie and Ontario. 8 Working together to cut this in half – even by a third – would be like saving a Great Lake. Imagine what all that water could be doing! Certainly not bad for what could also be a very healthy change.

Are you in?


  1. United States Geological Survey. “Where Is Earth’s Water?.” Accessed January 22, 2019.
  2. Mekonnen, Mesfin M. and Arjen Y. Hoekstra. "Four Billion People Facing Severe Water Scarcity." Science Advances 2, no. 2 (2016). doi: 10.1126/sciadv.1500323
  3. Food and Agriculture Organization of the United Nations. “Water Withdrawal by Sector, Around 2010.” AQUASTAT Database. 2016.
  4. Hoekstra, Arjen Y. and Ashok K. Chapagain. Globalization of Water: Sharing the Planet’s Freshwater Resources. Malden: Blackwell, 2008.
  5. Mekonnen, Mesfin M. and Arjen Y. Hoekstra. “A Global Assessment of the Water Footprint of Farm Animal Products.” Ecosystems 15 (2012). doi: 10.1007/s10021-011-9517-8
  6. “Hidden Water.” National Geographic, April 2010.
  7. Hoekstra, A.Y. and A.K. Chapagain. "Water Footprints of Nations: Water Use by Person as a Function of Their Consumption Pattern." Water Resource Management 21, no. 1 (2007). doi: 10.1007/s11269-006-9039-x
  8. Hoekstra, Arjen Y. “The Hidden Water Resource Use Behind Meat and Dairy.” Animal Frontiers 2, no. 2 (2012). 3-8. doi: 10.2527/af.2012-0038
  9. Mekonnen, M.M. and Hoekstra, A.Y. "The Green, Blue, and Grey Water Footprint of Crops and Derived Crop Products." Hydrology and Earth System Sciences 15 (2011). doi: 10.5194/hess-15-1577-2011
  10. Raatz, Susan. “Nutritional Value of Dry Beans.” The Bean Institute. Accessed January 31, 2020.
  11. United States EPA. “How We Use Water.” WaterSense. Accessed January 31, 2020.
  12. Novakovic, Z. et al. “Lifetime Production of High-Yielding Dairy Cows.” Biotechnology in Animal Husbandry 30, no. 3 (2014). doi: 10.2228/BAH1403399N
  13. DAIReXNET. “How Many Pounds of Feed Does a Cow Eat in a Day?.” August 16, 2019.
  14. Poore, J. and T. Nemecek. "Reducing Food's Environmental Impacts Through Producers and Consumers." Science 360 (2018). doi: 10.1126/science.aaq0216
  15. Whiting, Tabitha. “What Milk Should You Buy To Reduce Your Environmental Impact?.” Medium. May 18, 2019.
  16. Meyer, Zlati. “Beef Is Back on the Grill and Its Sales Are Heating Up, Too.” USA Today. July 5, 2017.
  17. Evstatieva, Monika and Audie Cornish. “Why Are Americans Drinking Less Cow’s Milk? Its Appeal Has Curdled.” NPR. May 16, 2017.

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