The Water Content of Things: How much water does it take to grow a hamburger?
Water is needed not only to grow everything we eat but also to produce almost all the products we use every day. This water is supplied by nature as precipitation or added by people during the growing and production process. You can't tell by the size of a product or the appearance of a particular food how much water was actually used to produce the item.
Bread, 1 pound (lb) (.45 kilogram (kg)) loaf: Your answer: gallons Correct answer: About 200 (193) gallons, 731 liters) 193 gallons is an estimated global average. Actual production and use of the wheat flour uses 80% of the water. Source:Water Footprint
Chicken, 1 pound (.45 kg) of meat: Your answer: gallons Correct answer: 500 gallons/pound (1,890 liters/.45 kg) Water is needed for the chicken to drink and, to maintain the chicken house, and for growing the grains that the chicken eats. Source:Water Footprint
Coffee, 1 cup: Your answer: gallons Correct answer: 35 gallons (132 liters) The world population requires about 120 billion cubic meters of water per year in order to be able to drink coffee. This is equivalent to 1.5 times the annual Rhine River runoff and constitutes 2% of the global water use for crop production. Source:Water Footprint
Corn, 1 pound (.45 kg): Your answer: gallons Correct answer: 110 gallons (416 liters) Maize (corn) consumes about 550 billion cubic meters of water annually, which is 8% of global water use for crop production. Source:: Water Footprint
Eggs, 1 egg: Your answer: gallons Correct answer: 50 gallons (189 liters) Most of the water is required for feeding the chickens. Source:Water Footprint
Hamburger (beef, in general) (1/4 pound, 113 grams) : Your answer: gallons Correct answer: About 460 gallons for 1/4 pound of beef, or about 1,750 liters per 113 grams Estimates vary a lot due to different conditions of raising cows.The number also varies depending on how far back in the production chain you go. It takes a lot of water to grow grain, forage, and roughage to feed a cow. Water is also needed for drinking supplies as well as for servicing the cow. Per kilogram of product, animal products generally have a larger water footprint than crop products. Source:Water Footprint
Orange (150 grams): Your answer: gallons Correct answer: 13 gallons (49 liters) One glass of orange juice (200 ml) takes about 45 gallons (170 liters) of water. Source:Water Footprint
Paper, sheet: Your answer: gallons Correct answer: 3 gallons (11 liters) This number has a lot of variation and depends on the source of the wood; 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
One cotton shirt: Your answer: gallons Correct answer: 650 gallons (2,495 liters/250 grams shirt) 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 fertilizers in the field and the use of chemicals in the textile industry. Source:Water Footprint
Wheat: Your answer: gallons Correct answer: 110-250 gallons (415-946 liters) Wheat consumes about 790 billion cubic meters of water annually, which constitutes 12% of global water use for crop production. Source:Water Footprint
Note: These numbers are only estimates. It is difficult to come up with accurate water-use numbers. The large variety of food-growing and production techniques used worldwide means that the amount of water needed can vary by a huge amount. Another consideration is how far back to go in the chain of production to estimate water use. For beef, some estimates consider only water used for drinking and for maintenance of the animals, while other sources may consider the water needed to grow the food that the cow eats. Keep in mind the limitations and uncertainties in coming up with these estimates.