The water footprint is an indicator of water use and looks at both direct and indirect use of water. It includes water consumption and pollution throughout the full production cycle from the supply chain to the end-user. The water footprint can measure the amount of water used in a single process (e.g. growing crops) or to create a product (e.g. T-shirt, cup of coffee). It can also cover the amount of water resources taken up by a company or provide information on the water use that is embedded in a country’s import and export patterns. The concept of water footprint is rooted in the recognition that human impacts on freshwater systems can ultimately be linked to human consumption and that issues like water shortages and pollution can be better understood and addressed by considering production and supply chains as a whole. Calculating one’s personal water footprint provides surprising information and motivates changes in consumption behaviour, making it a good tool for social change.
Depending on the entity or product whose water footprint is measured, it can be given in metres per tonne of production, per hectare of cropland, per unit of currency, and in other functional units. The water footprint looks at green, blue, and grey water. By considering them jointly, it provides a comprehensive picture of water use by identifying the source of water consumed, either as rainfall/soil moisture or surface/ground water, and the volume of fresh water required for the assimilation of pollutants.
Calculating water footprints offers surprising answers to a broad range of questions for consumers, policy makers and companies. Those questions include: Where is the water dependence in my company’s operations or supply chain? Are existing regulations protecting our water resources well enough? How secure are our food or energy supplies? Can I do something to reduce my own water footprint and help manage water for both people and nature?
Many countries have significantly externalized their water footprint and import water-intensive goods from elsewhere (see the Tool on Virtual Water C1.03). The water footprint visualises the hidden water use behind products thereby facilitating an understanding of the global character of fresh water and to the effects of consumption and trade on water resources. Uncovering the link between consumption and water use further helps to formulate new strategies for water governance, since new triggers for change are identified. Traditionally, final consumers, retailers, food industries, and traders in water-intensive products have not been considered responsible for good water governance. The concept of the water footprint puts them in the picture and identifies them as potential agents of change.
- The water footprint helps water managers to know the extent to which scarce water resources in the basin are allocated to low-value export crops.
- For companies, the water footprint helps to identify their dependence on scarce water resources in the supply-chain. It also provides them with ways to contribute to lowering the impacts on water systems throughout the supply chain operations.
- The concept of a water footprint brings water consumption and pollution along with entire production and supply chains to the attention of water scientists and practitioners.
- In an awareness raising campaign, the water footprint is a good way to communicate complex relations to a wider audience (see C8.02).
Photo: By by Lili Csóti, Marcell Hajdu and Boglárka Jelinek, Kaposvári Kodály Zoltán Központi Általános Iskola, Kaposvár, Hungary - GWP Central and Eastern Europe photo competition.