Water use

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Water use can mean the amount of water used by a household or a country, or the amount used for a given task or for the production of a given quantity of some product or crop. The term "water footprint" is often used to refer to the amount of water used by an individual, community, business, or nation.

World water use has been growing rapidly in the last hundred years (see graph from New Scientist article[1]). From 1900 to 2000, water use for agriculture went from about 500 to 2,500 cubic kilometers per year, while total use rose from around 600 to more than 3,000 cubic kilometres per year. Agriculture uses 70% of water resources.[2]

The total water footprint of a typical 3-person household in the U.S. is 23,360 liters (6171 gallons).[3] By comparison, a typical single family home in the U.S. only uses about 262 liters (69.3 gallons) of water per day (2008 estimate). This includes (in decreasing order) toilet use, washing machine use, showers, baths, faucet use, and leaks.[4][better source needed]

Water footprint[edit]

The water footprint of an individual, community or business is defined as the total volume of freshwater used to produce the goods and services consumed by the individual or community or produced by the business. Water use is measured in water volume consumed (evaporated) and/or polluted per unit of time. A water footprint can be calculated for any well-defined group of consumers (e.g., an individual, family, village, city, province, state or nation) or producers (e.g., a public organization, private enterprise or economic sector). The water footprint is a geographically explicit indicator, not only showing volumes of water use and pollution, but also the locations.[5][6]

The water footprint of a country is related to what its people eat. In 1993, Professor John Allan (2008 Stockholm Water Prize Laureate), strikingly demonstrated this by introducing the "virtual water" concept,[6][7] which measures how water is embedded in the production and trade of food and other products. For example, it is a common thought that the water involved in a cup of coffee is just the water in the cup.[6] There is actually 140 litres of water involved. The 140 litres of water is the amount of water that was used to grow, produce, package, and ship the coffee beans.[6] A hamburger needs an estimated 2,400 litres of water. This hidden water is technically called virtual water.[6] Therefore, eating a lot of meat means a large water footprint. The more food comes from irrigated land, the larger is the water footprint.[8]


The water footprint concept was introduced in 2002 by Arjen Y. Hoekstra from UNESCO-IHE as an alternative indicator of water use.[9] The concept was refined and accounting methods were established with a series of publications from two lead authors A.K. Chapagain and A.Y. Hoekstra from the UNESCO-IHE Institute for Water Education, later moved to WWF-UK and University of Twente in the Netherlands respectively. The most elaborate publications on how to estimate water footprints are a 2004 report on the "Water footprint of nations" from UNESCO-IHE [10] and the 2008 book Globalization of Water,[11] and the 2011 manual “The water footprint assessment manual: Setting the global standard”.[12] Cooperation between global leading institutions in the field has led to the establishment of the Water Footprint Network in 2008 that aims to coordinate efforts to further develop and disseminate knowledge on water footprint concepts, methods and tools.

Water Footprint Network (WFN)[edit]

The Water Footprint Network is an international learning community (non-profit foundation under Dutch law) that serves as a platform for connecting communities interested in sustainability, equitability and efficiency of water use. The organization has two work programmes: a Technical Work Programme and a Policy Work Programme. In addition, there is a Partner Forum which offer partners of the WFN a way of receiving, contributing and exchanging knowledge and experience on water footprint. Its mission and activities are listed below and taken directly from the Water Footprint website.[13]

The blue water footprint is the volume of freshwater that evaporated from the global blue water resources (surface water and ground water) to produce the goods and services consumed by the individual or community (either lost through evapotranspiration, incorporated in products or transferred to non-blue catchments).

The green water footprint is the volume of water evaporated from the global green water resources (rainwater stored in the soil as soil moisture) during production or those incorporated in products.

The grey water footprint is the volume of polluted water that associates with the production of all goods and services for the individual or community. The latter can be estimated as the volume of water that is required to dilute pollutants to such an extent that the quality of the water remains at or above agreed water quality standards. It is calculated as WF_{proc, grey}=\frac{L}{c_{max}-c_{nat}} where L is the pollutant load (as mass flux), cmax the maximum allowable concentration and cnat the natural concentration of the pollutant in the receiving water body (both expressed in mass/volume).[14]

Being sustainable means using blue water wisely and not making grey water.[15] Humans have polluted much water. Some rivers have so much rubbish in place that boats are pushing their way through the rubbish, for example, the Lake Karachay in Russia. It was the dumping site for radioactive waste, the water under the rubbish has chemicals from factories and toilets.

Calculation for different actors[edit]

The water footprint of a process is expressed as volumetric flow rate of water. That of a product is the whole footprint (sum) of processes in its complete supply chain divided by the number of product units. For consumers, businesses and geographic area, water footprint is indicated as volume of water per time, in particular:[14]

  • That of a consumer is the sum of footprint of all consumed products.
  • That of a community or a nation is the sum for all of its members resp. inhabitants.
  • That of a business is the footprint of all produced goods.
  • That of a geographically delineated area is the footprint of all processes undertaken in this area. The virtual water balance of an area is the net import of virtual water Vi, net, defined as the difference of the gross import Vi of virtual water from its gross export Ve. The water footprint of national consumption WFarea,nat results from this as the sum of the water footprint of national area and its virtual water balance.

International standard[edit]

In February 2011, the Water Footprint Network, in a global collaborative effort of environmental organizations, companies, research institutions and the UN, launched the Global Water Footprint Standard. On July 24, 2014, ISO issued ISO 14046:2014, Environmental management—Water footprint—Principles, requirements and guidelines. [1] The ISO standard is based on the Global Water Footprint Standard, which can be applied for different sorts of Water Footprint Assessment: for products, companies, countries or river basins.

Life Cycle Analysis of water use[edit]

Life Cycle Analysis (LCA) is a systematic, phased approach to assessing the environmental aspects and potential impacts that are associated with a product, process or service. “Life cycle” “refers to the major activities in the course of the product’s life-span from its manufacture, use, and maintenance, to its final disposal, including the raw material acquisition required to manufacture the product”.[16] Thus a method for assessing the environmental impacts of freshwater consumption was developed. It specifically looks at the damage to three areas of protection: human health, ecosystem quality, and resources. The consideration of water consumption is crucial where water-intensive products (for example agricultural goods) are concerned and need to therefore undergo a life-cycle assessment.[17] In addition, regional assessments are equally as necessary as the impact of water use depends on its location. In short, LCA is important as it identifies the impact of water use in certain products, consumers, companies, nations, etc. which can help reduce the amount of water used.

Water footprint of products[edit]

The water footprint of a product is the total volume of freshwater used to produce the product, summed over the various steps of the production chain. The water footprint of a product refers not only to the total volume of water used; it also refers to where and when the water is used (Source: WFN Glossary). The Water Footprint Network maintains a global database on the water footprint of products: WaterStat

An individual’s daily diet of fruits, vegetables and grains requires more than 1,500 litres (396.3 US gal) of water, as compared to 3,400 litres (898.2 US gal) needed for a daily diet rich in animal protein.[2] Research by the Cranfield University calculated the amount of water required to produce various common foods in the United Kingdom:[18]

Product Amount in litres Amount in gallons
1 cup of tea 32.4 l 8.6 US gal
1 imperial pint of beer 160 l 42.3 US gal
1 glass of wine 120 l 31.7 US gal
1 glass of milk 200 l 52.8 US gal
1 kilogram (2.2 lb) of beef 15,000 l 3,962.6 US gal
1 kilogram (2.2 lb) of poultry 6,000 l 1,585.0 US gal
250 grams (8.8 oz) packet of M&M's 1153 l 304.6 US gal
575 grams (20.3 oz) jar of Dolmio pasta sauce 202 l 53.4 US gal

For more product water footprints: see the Product Gallery of the Water Footprint Network

Water footprint of individual consumers[edit]

The water footprint of an individual refers to the sum of his or her direct and indirect freshwater use. The direct water use is the water used at home, while the indirect water use relates to the total volume of freshwater that is used to produce the goods and services consumed.

The average global water footprint of an individual is 1,385 m3 per year. Residents in some example nations have a water footprints as shown in the table:

Nation annual water footprint
China 1,071 m3[19]
Finland 1,733 m3[20]
India 1,089 m3[19]
United Kingdom 1,695 m3[21]
United States 2,842 m3[22]

Water footprint of companies[edit]

The water footprint of a business, the 'corporate water footprint', is defined as the total volume of freshwater that is used directly or indirectly to run and support a business. It is the total volume of water use to be associated with the use of the business outputs. The water footprint of a business consists of water used for producing/manufacturing or for supporting activities and the indirect water use in the producer’s supply chain.

The Carbon Trust argue that a more robust approach is for businesses to go beyond simple volumetric measurement to assess the full range of water impact from all sites. Its work with leading global pharmaceutical company GlaxoSmithKline (GSK) analysed four key categories: water availability, water quality, health impacts, and licence to operate (including reputational and regulatory risks) in order to enable GSK to quantitatively measure, and credibly reduce, its year-on-year water impact.[23]

The Coca-Cola Company operates over a thousand manufacturing plants in about 200 countries. Making its drink uses a lot of water. Critics say its water footprint has been large. Coca-Cola has started to look at its water sustainability.[24] It has now set out goals to reduce its water footprint such as treating the water it uses so it goes back into the environment in a clean state. Another goal is to find sustainable sources for the raw materials it uses in its drinks, such as sugarcane, oranges, and corn. By making its water footprint better, the company can reduce costs, improve the environment, and benefit the communities in which it operates.[15]

Water footprint of nations[edit]

The water footprint of a nation is the water used to produce the goods and services consumed by the inhabitants of the nation. The internal water footprint is the appropriation of domestic water resources; the external water footprint is the appropriation of water resources in other countries. About 65% of Japan's total water footprint comes from outside the country; about 7% of the Chinese water footprint falls outside China.[6]


Each EU citizen consumes 4,815 litres of water per day on average, 44% is used in power production primarily to cool thermal plants or nuclear power plants. Energy production annual water consumption in the EU 27 in 2011 was as billion m3 for gas 0.53, coal 1.54 and nuclear 2.44. Wind energy avoided the use of 387 million cubic metres (mn m³) of water in 2012 avoiding a cost of €743 mn. The cost of droughts in Europe over the past thirty years is according to the European Commission €100 billion.[25][26]


Insufficient consideration of consequences of proposed water saving policies to farm households[edit]

According to Dennis Wichelns of the International Water Management Institute: Although one goal of virtual water analysis is to describe opportunities for improving water security, there is almost no mention of the potential impacts of the prescriptions arising from that analysis on farm households in industrialized or developing countries. It is essential to consider more carefully the inherent flaws in the virtual water and water footprint perspectives, particularly when seeking guidance regarding policy decisions.[27]

Insufficient consideration of regional water scarcity[edit]

The application and interpretation of water footprints may sometimes be used to promote industrial activities that lead to facile criticism of certain products. For example, the 140 litres required for coffee production for one cup [6] might be of no harm to water resources if its cultivation occurs mainly in humid areas, but could be damaging in more arid regions. Other factors such as hydrology, climate, geology, topography, population and demographics should also be taken into account. Nevertheless, high water footprint calculations do suggest that environmental concern may be appropriate.

The use of the term "footprint" can also confuse people familiar with the notion of a carbon footprint, because the water footprint concept includes sums of water quantities without necessarily evaluating related impacts. This is in contrast to the carbon footprint, where carbon emissions are not simply summarized but normalized by CO2 emissions, which are globally identical, to account for the environmental harm. The difference is due to the somewhat more complex nature of water; while involved in the global hydrological cycle, it is expressed in conditions both local and regional through various forms like river basins, watersheds, on down to groundwater (as part of larger aquifer systems).

The water footprint of a business, the 'corporate water footprint', is defined as the total volume of fresh water that is used directly or indirectly to run and support a business. It is the total volume of water use to be associated with the use of the business outputs. The water footprint of a business consists of water used for producing/manufacturing or for supporting activities and the indirect water use in the producer’s supply chain. Water Credit for conserving water: Nagpur based innovator Shripad Vaidya's idea of giving water credit's, much like carbon credits, to those who save and conserve water is gaining ground. These water credits can be marketed or sold to those in need of surplus water for social,agricultural or industrial ventures.[28][29][30]

See also[edit]


  1. ^ "Looming water crisis simply a management problem" by Jonathan Chenoweth, New Scientist 28 Aug., 2008, pp. 28-32.
  2. ^ a b Nitti, Gianfranco (May 2011). "Water Is Not an Infinite Resource and the World is Thirsty". The Italian Insider (Rome). p. 8. 
  3. ^ "Mekonnen, M.M. and Hoekstra, A.Y.,National water footprint accounts: the green, blue and grey water footprint of production and consumption, Value of Water Research Report Series No. 50, UNESCO-IHE, Delft, the Netherlands." (PDF). Water Footprint Network. 2011. Archived from the original on 2014. 
  4. ^ "Cashing in on climate change". IBISWorld. 29 May 2008. Archived from the original on 4 October 2008. 
  5. ^ Definition taken from the Hoekstra, A.Y. and Chapagain, A.K. (2008) Globalization of water: Sharing the planet's freshwater resources, Blackwell Publishing, Oxford, UK.[2]
  6. ^ a b c d e f g "Waterfootprint.org: Water footprint and virtual water". The Water Footprint Network. Retrieved 9 April 2014. 
  7. ^ Allan, Tony (2011). Virtual water : tackling the threat to our planet's most precious resource. London: I.B. Tauris. ISBN 978-1845119836. 
  8. ^ Morelli, Angela (2012). "Virtual Water - Discover how much WATER we EAT everyday". Retrieved 9 April 2014. 
  9. ^ Hoekstra, A.Y. (2003) (ed) Virtual water trade: Proceedings of the International Expert Meeting on Virtual Water Trade, IHE Delft, the Netherlands [3]
  10. ^ [4]
  11. ^ Globalization of Water, A.Y. Hoekstra and A.K. Chapagain, Blackwell, 2008
  12. ^ Hoekstra, Arjen (2011). The water footprint assessment manual: Setting the global standard (PDF). London: Earthscan. ISBN 978-1-84971-279-8. 
  13. ^ "Why a Water Footprint Network". Water Footprint Network. Retrieved 2013. 
  14. ^ a b "The Water Footprint Assessment Manual". Water Footprint Network. Retrieved 2015-01-20. 
  15. ^ a b Naumann, Ruth (2011). Sustainability (1st ed. ed.). North Shore, N.Z.: Cengage Learning. pp. 56–58. ISBN 978-017021-034-8. 
  16. ^ Scientific Applications International Corporations (SAIC) (2006). Life Cycle Assessment: Principles and Practice. Reston, VA: SAIC. 
  17. ^ Pfister, Stephan; Koehler, Annette; Hellweg, Stefanie (20 March 2009). "Assessing the Environmental Impacts of Freshwater Consumption in LCA". Environmental Science 43: 4008–104. 
  18. ^ Davies, Jack (31 March 2009). "Experts warn of major UK water shortage". Farmers Guardian. Retrieved 30 May 2011. 
  19. ^ a b Hoekstra, AY (2012). "The Water Footprint of Humanity". PNAS. doi:10.1073/pnas.1109936109. 
  20. ^ Data obtained from the Finnish Wikipedia article page Vesijalanjälki
  21. ^ Chapagain, A.K. and Orr, S. "U.K. Water Footprint: The Impact of the U.K.'s Food and Fibre Consumption on Global Water Resources, Volume 1" (PDF). WWF-UK (WWF-UK).  and volume 2 Chapagain, A.K. and Orr, S. "Volume 2" (PDF). WWF-UK (WWF-UK). 
  22. ^ "The Water Footprint of Humanity".  JournalistsResource.org, retrieved 20 March 2012
  23. ^ "Water, water everywhere... or is it?", The Carbon Trust, 26 November 2014. Retrieved on 20 January 2015.
  24. ^ "2013 Water Report: The Coca-Cola Company". The Coca-Cola Company. Retrieved 8 April 2014. 
  25. ^ Saving water with wind energy EWEA June 2014
  26. ^ Saving water with wind energy Summary EWEA
  27. ^ Wichelns, Dennis (2010). "Virtual water and water footprints offer limited insight regarding important policy questions". International Journal of Water Resources Development 26 (4): 639–651. doi:10.1080/07900627.2010.519494. Retrieved 2015-01-21. 
  28. ^ http://www.scribd.com/doc/97302583/Water-use
  29. ^ Limca Book of Records2012 page 278
  30. ^ https://arnoneumann.wordpress.com/tag/environment-2/page/2/

External links[edit]