Every person has a “water footprint,” which is the amount of fresh water that we use daily, plus the water required to produce any goods and services that we also consume. The former gets more attention than the latter, since household water use is easier to track, thanks to the monthly water bill. It’s common to think about water consumption in terms of how long you’re in the shower, how often you run the dishwasher, whether you left the sprinkler on, or someone forgot to turn off the tap.
But it’s important not to forget the water footprint of external goods and services, such as foods, because it’s probably larger than you suspect. Here is a disturbing list of how many gallons of water are needed to produce various products (via National Geographic, “The Hidden Water We Use”).
1 gallon (3.8 litres) of milk requires 880 gallons (3,331 L) of water.
1 gallon of wine requires 1,008 gallons of water.
1 gallon of coffee requires 880 gallons of water. “If everyone in the world drank a cup of coffee each morning, it would ‘cost’ about 32 trillion gallons (120 billion cubic metres) of water a year.”
1 gallon of tea requires 128 gallons of water.
1 cup of orange juice requires 53 gallons of water.
1 pound (0.5 kg) of wheat requires 132 gallons (500 L) of water. “Wheat production accounts of 12 percent of global water use for the planet’s total agricultural crop production.”
1 pound of rice requires 449 gallons of water.
1 pound of corn requires 108 gallons of water
1 pound of beef requires 1,799 gallons of water.
1 pound of goat requires 127 gallons of water.
1 pound of pork requires 576 gallons of water.
1 pound of chicken requires 468 gallons of water.
1 cotton T-shirt requires 713 gallons of water.
500 sheets of paper require 1,321 gallons of water.
1 lb of chocolate requires 3,170 gallons of water.
Professor Arjen Hoekstra created the concept of the water footprint: “Many countries have significantly externalized their water footprint, importing water-intensive goods from elsewhere. This puts pressure on the water resources in the exporting regions, where too often mechanisms for wise water governance and conservation are lacking.” Twenty percent of the U.S. water footprint -- 750, 248 cubic gallons per person annually -- is external, interestingly located in the Yangtze River basin of China.
While we can’t stop buying food altogether, it is possible to make consumer choices that limit the amount of water used to maintain our lifestyle. Go vegetarian, or at least opt for less wasteful meats, such as goat. Order a soy burger instead of beef. Drink water straight from the tap instead of coffee, tea, or orange juice. Don’t buy that extra cotton T-shirt.
Keep in mind that water scarcity affects 2.7 billion people worldwide for at least a month each year. Water should not be treated as disposable. It’s a privilege, and deserves great respect because, without it, we cannot survive.