If we consider that an average German household consumes around 120 litres per capita and day, and even though it seems that Germans tend to consume less and less water ‘directly’, they are one of the largest consumers of so called virtual water due to their consumption and living habits. If that amount is added to the 120 litres, we have a much higher per capita consumption that is much closer linked to the water users Agriculture and Industry, than we might have thought. Even though we might not see our indirect water consumption in daily life easily, a substantial volume of water relates to our commodities consumed e.g. a bunch of flowers bought in Berlin may have been grown in and imported from Kenya, a Sweater bought in Portugal may have been manufactured in India with cotton imported from Bangladesh or India. In this second case, we do not only have to think of the water that is used for irrigation purposes and might increase overexploitation of groundwater and surface waters, but also, that from industrial procedures like dyeing, local streams are polluted. These externalities are often not reflected in the price of the commodities, and consumers are not aware of their global water footprint.
The interest in the 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, […]
Professor Arjen Y. Hoekstra,
Creator of the water footprint concept.
Considering this, ecological footprints of different goods and services are the result of global trade, individual consumption habits and the import of water-intensive goods from elsewhere. In general we can differentiate between:
- Blue Water Footprint
Consumption of blue water resources - surface and groundwater - along the supply chain of a product
- Green Water Footprint
Consumption of green water resources - rainwater insofar as it does not become runoff.
- Grey Water Footprint
Refers to pollution and is defined as the volume of freshwater that is required to assimilate the load of pollutants given natural background concentrations and existing ambient water quality standards
The externalization of a country's water footprint puts increasing pressure on natural resources especially in regions already facing water stress or scarcity. If exporting regions are furthermore lacking wise water governance they face increasing challenges in balancing their natural resources. So, how to satisfy international trade and consumers’ demands while securing a sustainable water sector development?