What is
Water Footprint?
Did you know that behind every cup of coffee, t-shirt, or book you pick up, there is a vast amount of water hidden?
The amount of water consumed in the production of each product is measured using the so-called water footprint. This indicator includes all the water used throughout the entire production process – from growing raw materials, through processing, to the final product. Sometimes this water is also referred to as virtual water because it is not directly visible, but it is an essential part of every product we use.
How is the water footprint calculated?
The calculation of the water footprint is a process that takes into account the various ways water is used during the production of goods. It’s not just about the amount of water we directly consume, but also the hidden water that is used throughout the entire production cycle – from sourcing raw materials, through processing, to final distribution. This process includes three main types of water:
Blue water
This refers to the amount of water withdrawn from natural sources, such as rivers, lakes, or groundwater. For instance, it includes water used for irrigating crops or in manufacturing processes.
Green water
Green water refers to water from natural precipitation that infiltrates the soil and is used by plants during their growth. It is the rainwater that crops and vegetation absorb directly from the environment, without needing to be drawn from rivers, lakes, or groundwater sources. This type of water is especially crucial in agriculture.
Gray water
The amount of water needed to dilute pollution generated during the production process is known as gray water. It can be thought of as the water used to "clean" wastewater, ensuring it meets cleanliness standards before being safely released back into the environment. This type of water plays a crucial role in managing environmental impact and maintaining water quality.
How Much Water Do Individual Products "Cost"?
On our water marketplace, we have delved into the world of water consumption and mapped out how much water individual products "cost." Of course, these are estimates based on available studies and data, so take everything with a grain of salt—the actual figures depend on various factors, such as production methods or technologies used by manufacturers. Nevertheless, these estimates help us better understand how products impact our water balance. Whether it's the production of clothing, food, or even books, every product has its own "water footprint," which can be quite surprising.
Apple
It takes approximately 123 liters of water to grow one apple. Most of this water comes from natural precipitation (green water) that the trees absorb during their growth. However, some of the water may also come from artificial irrigation (blue water) if the apples are grown in drier areas.
123 liters of water 822 (m³/ton)
🔵 16.2 % 🟢68.3 % ⚪15.4 %
Mekonnen, M. M., & Hoekstra, A. Y. (2011). The green, blue and grey water footprint of crops and derived crop products. Hydrology and earth system sciences, 15(5), 1577-1600.
Egg
An egg may be small, but it still carries its own water footprint. Approximately 175 liters of water are needed to produce one egg. Most of this water is used for growing feed for the hens, which includes both blue water for irrigation and green water from rainfall. The egg itself is not very water-intensive, but the entire production process demands its share of water.
175 liters of water 3 265 (m³/ton)
🔵7.47 %🟢79.39 % ⚪13.14 %
Mekonnen, M.M., Hoekstra, A.Y. A Global Assessment of the Water Footprint of Farm Animal Products. Ecosystems 15, 401–415 (2012). https://doi.org/10.1007/s10021-011-9517-8
Bar of chocolate
Chocolate is produced from cocoa beans and sugar, with the largest cocoa producers being Côte d'Ivoire, Ghana, Indonesia, Nigeria, and Ecuador. The water footprint of chocolate depends on the cultivation methods used—most of the water comes from rainfall (green water), while only a small amount comes from intensive irrigation (blue water). Additionally, the use of fertilizers and pesticides can pollute water (gray water), as well as the processes of production, packaging, and transportation of chocolate.
1700 liters of water 17 196 (m³/ton)
🔵 1.2 % 🟢97.7 % ⚪6.9 %
Mekonnen, M. M., & Hoekstra, A. Y. (2011). The green, blue and grey water footprint of crops and derived crop products. Hydrology and earth system sciences, 15(5), 1577-1600.
https://watercalculator.org/water-footprint-of-food-guide/
Cup of Coffee
The top producers of coffee beans are Brazil, Vietnam, Colombia, and Indonesia. Shade-grown coffee plants utilize rainwater (green water), while sun-grown varieties require intensive irrigation (blue water). Coffee cultivation can pollute water due to the use of fertilizers and pesticides (gray water) and the resource-intensive processing, particularly wet washing. Dry processing is more water-efficient but still consumes a certain amount of water. Additionally, pollution related to the packaging and transportation of coffee further contributes to its overall water footprint.
130 liters of water 15 897 (m³/ton)
🔵0.73 %🟢95.91 % ⚪3.35%
Mekonnen, M.M., Hoekstra, A.Y. A Global Assessment of the Water Footprint of Farm Animal Products. Ecosystems 15, 401–415 (2012). https://doi.org/10.1007/s10021-011-9517-8
https://watercalculator.org/water-footprint-of-food-guide/
Cup of Tea
Tea, a popular beverage worldwide, is primarily grown in countries like China, India, Kenya, Sri Lanka, and Vietnam, where tea plants mainly rely on rainwater (green water). However, in drier areas, they may receive supplementary irrigation (blue water). During cultivation, fertilizers and pesticides are sometimes used, contributing to gray water, which is further associated with the processing, packaging, and transportation of tea.
27 liters of water 8 856 (m³/ton)
🔵 10,14 % 🟢81,66 % ⚪ 8,20 %
Mekonnen, M. M., & Hoekstra, A. Y. (2011). The green, blue and grey water footprint of crops and derived crop products. Hydrology and earth system sciences, 15(5), 1577-1600.
https://watercalculator.org/water-footprint-of-food-guide/
Bottle of Beer (330 ml)
Beer is not only a popular beverage but also a product with a significant water footprint. The largest beer producers are China, the USA, Brazil, and Mexico. Most of this water is consumed in the cultivation of raw materials, such as barley and hops, while the remainder is used in the actual brewing process. The Czech Republic, renowned for its beer tradition, ranks 21st among the world's beer producers.
99 liters of water 300 (m³/ton)
🔵5 %🟢86 % ⚪9%
Mekonnen, M.M., Hoekstra, A.Y. A Global Assessment of the Water Footprint of Farm Animal Products. Ecosystems 15, 401–415 (2012). https://doi.org/10.1007/s10021-011-9517-8
https://watercalculator.org/water-footprint-of-food-guide/
Chicken Meat (100 g)
Chickens are primarily raised in the USA, China, Brazil, and the EU. This production mainly relies on rainwater (green water) and irrigated water (blue water). However, raising chickens can lead to water pollution (gray water) due to manure runoff and the use of fertilizers and pesticides in feed production.
433 liters of water 4 325 (m³/ton)
🔵 7,2 % 🟢82 % ⚪10,8 %
Mekonnen, M. M., & Hoekstra, A. Y. (2011). The green, blue and grey water footprint of crops and derived crop products. Hydrology and earth system sciences, 15(5), 1577-1600.
https://watercalculator.org/water-footprint-of-food-guide/
Beef (100 g)
Beef is primarily produced in the USA, Brazil, China, Argentina, and Australia. Cattle spend most of their lives on pasture but are fed corn and hay in feedlots towards the end of their lives. The feed mostly relies on rainwater (green water), but an increasing amount is irrigated. However, beef production can pollute water, as fertilizers and pesticides from fields and manure runoff can end up in rivers and lakes. The beef industry also has a significant environmental impact, as high water consumption and greenhouse gas emissions contribute to the degradation of natural resources. For instance, beef production requires about eight times more feed (on a dry weight basis) per kilogram of meat compared to pork and eleven times more than chicken.
1 542 liters of water 15 415 (m³/ton)
🔵3.6 %🟢93.5 % ⚪2.9%
Mekonnen, M.M., Hoekstra, A.Y. A Global Assessment of the Water Footprint of Farm Animal Products. Ecosystems 15, 401–415 (2012). https://doi.org/10.1007/s10021-011-9517-8
https://watercalculator.org/water-footprint-of-food-guide/
Slice of Bread
Bread made from wheat flour requires a significant amount of water for its production. Wheat, the main ingredient in bread, is primarily grown using rainwater (green water), but in some areas, irrigation (blue water) is also necessary. Additionally, gray water, which refers to pollution caused by the use of fertilizers and pesticides, can also contaminate water sources. In the Czech Republic, wheat is mainly cultivated in fields that utilize natural rainfall, and most of the water used for wheat production comes from these precipitation sources.
80 liters of water 1 608 (m³/ton)
🔵 18,7 % 🟢69,9 % ⚪ 11,4 %
Mekonnen, M. M., & Hoekstra, A. Y. (2011). The green, blue and grey water footprint of crops and derived crop products. Hydrology and earth system sciences, 15(5), 1577-1600.
https://watercalculator.org/water-footprint-of-food-guide/
Hamburger
The water footprint of a hamburger is influenced by the amount of water required to produce its individual ingredients. Average water footprint values per kilogram of ingredients are used for the calculation. The main components include the beef patty, a slice of tomato, a slice of cheese, a leaf of lettuce, and the bun. The beef has the largest water footprint because a significant amount of water is needed for feeding and raising cattle. Other ingredients, such as tomatoes, cheese, and lettuce, have a lower but still notable impact on the overall water footprint of the hamburger.
2 499 liters of water 15 415 (m³/ton)
🔵3.6 %🟢93.5 % ⚪2.9% (převážně hovězí maso)
Mekonnen, M.M., Hoekstra, A.Y. A Global Assessment of the Water Footprint of Farm Animal Products. Ecosystems 15, 401–415 (2012). https://doi.org/10.1007/s10021-011-9517-8
https://watercalculator.org/water-footprint-of-food-guide/
Cotton T-shirt
Cotton, the material from which t-shirts are made, is a very "thirsty" crop—requiring an enormous amount of water for cultivation. In addition, the actual production of textiles, such as dyeing and washing the fabric, is also water-intensive. Whether it's the irrigation of cotton or the processes in the textile industry, the water footprint of a single t-shirt is substantial.
2 720 liters of water
🔵 45,2 % 🟢40,8 % ⚪ 14,0 %
Chapagain, A. K., Hoekstra, A. Y., Savenije, H. H. G., & Gautam, R. (2006). The water footprint of cotton consumption: An assessment of the impact of worldwide consumption of cotton products on the water resources in the cotton producing countries. Ecological Economics, 60(1), 186-203. https://doi.org/10.1016/j.ecolecon.2005.11.027
Jeans
The production of a single pair of jeans requires approximately 11,000 liters of water. Water is consumed not only during the cultivation of cotton, from which the jeans are made, but also in later stages such as dyeing, finishing, and washing the fabric. These processes not only increase water consumption but also lead to pollution—industrial wastewater contains large amounts of dyes and chemicals. With over 3.5 billion pairs of jeans produced annually, the scale of this environmental impact is significant.
10 850 liters of water
🔵45,2 %🟢 41,0 % ⚪ 13,8 %
Chapagain, A. K., Hoekstra, A. Y., Savenije, H. H. G., & Gautam, R. (2006). The water footprint of cotton consumption: An assessment of the impact of worldwide consumption of cotton products on the water resources in the cotton producing countries. Ecological Economics, 60(1), 186-203. https://doi.org/10.1016/j.ecolecon.2005.11.027
Sharma, D. (2020). Water footprint of denim industry. In Sustainability in denim (p. 111). Elsevier.
Leather Shoes
The water footprint of leather shoes is substantial, as their production involves several water-intensive processes. The majority of water is consumed during the cultivation of materials, such as leather and natural textiles, that make up the upper part of the shoes. Leather, primarily sourced from cattle, undergoes a tanning process, where it is treated with chemicals and water to make it durable and long-lasting. This process is water-intensive and often results in water pollution from chemicals and dyes. Additionally, significant water consumption occurs in the production of other materials, such as textiles and synthetic components. Water is also used during various manufacturing stages, including shaping and securing the form of the shoes.
8 000 liters of water
🔵 4, 0 % 🟢93,0 % ⚪ 2,9 % (kůže)
Muñoz, Z. R. (2013). Water, energy and carbon footprints of a pair of leather shoes [Master's thesis, Kungliga Tekniska högskolan]. Open Access.
Book
The overall water footprint ranges between 300 and 2,600 m³ per ton of paper, which corresponds to approximately 2 to 13 liters per A4 page. The largest portion of water is consumed during the cultivation of trees, with most of the water evaporating from the soil and leaves (known as green and blue water). Interestingly, using recycled paper can significantly reduce the water footprint—on average by 40%. Additionally, selecting locations for paper production and using tree species that require less water can contribute to lower water consumption.
300 liters of water
🔵1 %🟢 60 % ⚪ 39%
Rep, J. (2011). From forest to paper, the story of our water footprint. UPM-Kymmene, Helsinki.
Schyns, J. F., Booij, M. J., & Hoekstra, A. Y. (2017). The water footprint of wood for lumber, pulp, paper, fuel and firewood. *Advances in Water Resources, 107*, 490-501. https://doi.org/10.1016/j.advwatres.2017.05.013
10-Minute Shower
An average showerhead uses approximately 12 to 15 liters of water per minute, meaning that a 10-minute shower can consume up to 150 liters of water. For more water-efficient options, low-flow showerheads are available, which use 6 to 9 liters per minute, resulting in a total of 60 to 90 liters of water for a 10-minute shower.
100 liters of water
Water Marketplace Project
In the installation "Water Marketplace," we presented various objects that you can "purchase" to better visualize the water footprint of individual products. This topic, of course, relates to everything we use in our daily lives. The aim of our project was to illustrate daily water consumption in an engaging and interactive way. You can find more information about the project itself here: Prototype 2024.