The water footprint is an indication that how much water is used directly and indirectly by a human. Consumption of rainwater (green water), consumption of groundwater or surface water (blue water), and pollution of water (grey water) are the three major components of water footprint. We find the sudden interest in the water footprint as humans try to recognise the impact on fresh water systems which can be ultimately linked to the human consumption, and the resultant issues like water shortages and pollution. These issues are easy to understand and address if the entire production and supply chains are considered as a whole.
Common people these days are aware of their carbon footprint but they are mostly ignorant about the water footprint. It can be a startling eye opener for us when we realise that over 2.7 billion people across the world are affected by water scarcity for at least one month each year. This is so because though the water covers up 71% of the earth; the sources of fresh water constitute only 2.5% of it. Of the 2.5% fresh water only a small fraction is found on large water bodies rest all is in the form of glaciers and ice caps of Antarctica and Greenland.
The main two ways in which water use can be classified is in-stream and withdrawal. In-stream use for generating hydro-electricity, boating, swimming and such activities does not use up water but can pollute the water. Withdrawal for agricultural, industrial, thermal and nuclear power generation, livestock and household use does not return water to its source and so can be termed as consumption.
Over the span of few years it has been observed that many nations have externalised their water footprint by importing water-intensive products from other nations. For example about 10% of 1070 cubic meter per year per capita Chinese consumption of water falls outside China and 77% of 1380 cubic meter per year per capita Japanese consumption of water falls outside Japan. This tactic only results in increasing the pressure on the water resources in the exporting nations especially the nations that do not have proper water governance and conservation policies. However, this tactic is a boon for water-short countries when they import water-intensive agricultural goods from nations that have larger water endowments.
Most experts advise to consider the inherent flaws in the virtual water and water footprint perspectives especially when seeking guidance regarding policy decisions. This is so as few of the available estimates of prospective national and worldwide water savings made feasible by the way of global trade are quite large and do not reflect actual or latent opportunities to save water.
The major factors that determine the water footprint of a country are: Volume of consumption (in comparison with the gross national income); Consumption pattern (how much meat is consumed); Climate (conditions for growth of vegetation); and Agricultural practice (how efficiently water is used). Nations and individuals generally try to be ‘water neutral’ which means trying to reduce negative economic, social and environmental externalities as far as possible. Being ‘water neutral’ does not mean bringing down the water use to zero.
One way to be water neutral is to manage aquifer recharge (MAR). This system provides cheapest form of fresh and safe supply of water human. The extent to which MAR can achieve the potential for water supply depends on understanding of the capacity and limitation of various techniques used within the catchment and aquifer system in relation to the need of the community, existing water infrastructure, space available for water harvesting, regulations for harvesting and skills of people who install and manage the MAR.
The only way to make sure that the water is efficiently consumed is to make sure that not only the governments but also consumers, corporates and communities play an active role in better management of water resources. By harnessing rainwater, villages like Rajsamadhiya have become self-sufficient in their water supplies. India’s water footprint is below world average; however, huge population makes the country’s overall footprint too high. On a positive side India’s higher incidence of vegetarianism (approximately 30% of the population) does play a role in keeping individual footprints lower – the water contained in our diets varies with a vegetarian diet using 2.6 cubic meters of water each day, while a U.S.-style meat based diet uses over 5 cubic meters. At this juncture it will be interesting to know how much water we use directly and indirectly to produce one kg of following widely used products
|Product||Litres of water required|
|Mango / Guava||1,800|
Dillon, P., 2005, “Future Management of Aquifer Recharge”, Hydrogeology Journal, Vol. 13, No. 1, pp. 313-316
Hoekstra, A. Y., 2008, “Water Neutral: Reducing and Offsetting the Impacts of Water Footprints”, UNESCO-IHE Institute for Water Education, Research Report Series No. 28
Hoekstra, A. Y. and Chapagain, A. K., 2007, “Water Footprint of Nations: Water Use by People as a Function of Their consumption Pattern”, Water Resource Management, Vol. 21, No. 1, pp. 35-48.
http://www.waterfootprint.org/?page=files/home accessed on 10th September 2012.
Wichelns, D., 2010, “Virtual Water and Water Footprints Offer Limited Insight Regarding Important Policy Questions”, International Journal of Water Resources Development, Vol. 26, No. 4, pp. 639-651
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