The USGS Water Science School
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Water is needed to grow not only everything we eat but also to produce almost all the products we use every day. This water is either supplied by nature as precipitation and/or added by man during the growing/production process. You can't tell by the size of a product or the appearance of a food how much water was actually used to produce the item.
Bread, 1 slice, about 1 ounce:
Your answer: 0 gallons | Correct answer: 10 gallons
10 gallons is a good global average. Producing wheat takes about 150 gallons per pound.
Source: Water Footprint
Chicken, 1 pound of meat:
Your answer: 0 gallons | Correct answer: 500 gallons Water is not only needed for the chicken to drink and to maintain the "chicken house" but also to grow the grains that the chicken eats.
Source: The Water Content of Things.
Coffee, 1 cup:
Your answer: 0 gallons | Correct answer: 35 gallons The world population requires about 120 billion cubic metres of water per year in order to be able to drink coffee. This is equivalent to 1.5 times the annual Rhine runoff and constitutes 2 % of the global water use for crop production.
Source: Water Footprint
Corn, 1 pound:
Your answer: 0 gallons | Correct answer: 110 gallons Maize (corn) consumes about 550 billion cubic meters of water annually, which is 8 % of the global water use for crop production.
Source:: Water Footprint
Eggs, 1 egg:
Your answer: 0 gallons | Correct answer: 400 gallons Most of the water is required for feeding the chickens.
Source: Water Footprint
Hamburger :
Your answer: 0 gallons | Correct answer: 4,000-18,000 gallons Estimates vary a lot due to different conditions of raising cows and to the extent of the production chain of water that is used. It take a lot of water to grow grain, forage, and roughage to feed a cow, as well as water to drink and to service the cow.
Source: The Water Content of Things.
Orange:
Your answer: 0 gallons | Correct answer: 13 gallons One glass of orange juice (200 ml) takes about 45 gallons litres of water, which includes growing the orange, of course.
Source:Water Footprint
Paper:
Your answer: 0 gallons | Correct answer: 3 gallons This number has a lot of variation and depends on the source of the wood. Particularly, forest evapotranspiration and wood yield vary from forest to forest. The number will likely fall in a range of 1/2 gallon and 8 gallons per sheet (A4 size).
Source: Water Footprint
Potato:
Your answer: 0 gallons | Correct answer: 100 gallons
Source: The Water Content of Things.
One cotton shirt:
Your answer: 0 gallons | Correct answer: 700 gallons Of this total water volume, 45% is irrigation water consumed (evaporated) by the cotton plant; 41% is rainwater evaporated from the cotton field during the growing period; and 14% is water required to dilute the wastewater flows that result from the use of fertilisers in the field and the use of chemicals in the textile industry.
Source: Water Footprint
Steel:
Your answer: 0 gallons | Correct answer: 30 gallons
Source: The Water Content of Things.
Wheat:
Your answer: 0 gallons | Correct answer: 110-250 gallons Wheat consumes about 790 billion cubic meters of water annually, which constitutes 12 % of the global water use for crop production.
Source: The Water Content of Things.
Sources of information:
Note: These numbers are only estimates. It is not only very difficult to come up with accurate water-use numbers but the large variety of food-growing and production techniques used worldwide means that a the amount of water needed can vary by a huge amount. Also (yes, another "consideration") is how deep you go in the chain of production to estimate water use. For beef, some estimates consider water for cattle drink and to maintain the animals, while other sources may consider the water needed to grow the food that the cow eats. So, the data is meant to give you a general idea and please note the limitations and uncertainties in coming up with these estimates.
U.S. Department of the Interior |
U.S. Geological Survey
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