Calculating your water footprint
Water scarcity affects 2.7 billion people worldwide for at least a month each year and in the same way that each of us has a carbon footprint, Professor Arjen Hoekstra of the University of Twente in the Netherlands posits that every person also has a "water footprint". Our water footprint is calculated by counting the amount of fresh water that we each use daily and the amount of water required to produce the goods and services that we consume. Due in large part to our monthly water bill, we recognize our daily fresh water use more than we do the amount of water that it takes to produce other foods and products that we consume. We more commonly think about water consumption in terms daily showers dishwasher and sprinkler usage or dripping spigots.
But the water footprint of external goods and services, including food and daily consumables, is also an important consideration. Listed below are the aquatic production needs for various products as described in National Geographic’s, "The Hidden Water We Use".
-1 gallon of milk requires 880 gallons of water.
-1 gallon of wine requires 1,008 gallons of water.
-1 gallon of coffee requires 880 gallons of water, approximately 32 trillion gallons of water annually.
-1 gallon of tea requires 128 gallons of water.
- 1 cup of orange juice requires 53 gallons of water.
-1 pound of wheat requires 132 gallons of water accounting for 12% of global water use.
-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 pound of chocolate requires 3,170 gallons of water.
"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." In the United States, approximately 750,248 cubic gallons per person annually or 20% is external.
As consumers we need to consider our water footprint and make more sustainable consumer choices. These may include a vegetarian diet, choosing soy instead of beef, drinking tap water instead of coffee, tea or orange juice or simply eating less wasteful meats like goat and reducing our clothing and paper consumption.
Water is a necessity and must be treated more carefully.
Water footprint image via Shutterstock.