Water footprint
The water footprint is an indicator of water use that includes both direct and indirect water use of a consumer or producer.
The water footprint of an individual, community or business is defined as the total volume of freshwater that is 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

  1. Water Footprint
    The water footprint has been developed in analogy to the ecological footprint concept.
    Chapagain and Hoekstra (2003), described the new concept of water footprint, which is closely linked to the virtual water concept.
    Virtual water is defined as the volume of water required to produce a commodity or service.
    The concept was introduced by Allan in the early 1990's(Allan, 1993, 1994) when studying the option of importing virtual water (as opposed to real water) as a partial solution to problems of water scarcity in the Middle East.

    Allan elaborated on the idea of using virtual water import (coming along with food imports) as a tool to release the pressure on the scarcely available domestic water resources.

    Virtual water import thus becomes an alternative water source, next to endogenous water sources.
    Imported virtual water has therefore also been called 'exogenous water' (Haddadin, 2003).

    When assessing the water footprint of a nation, it is essential to quantify the flows of virtual water leaving and entering the country.

    If one takes the use of domestic water resources as a starting point for the assessment of a nation's water footprint, one should subtract the virtual water flows that leave the country and add the virtual water flows that enter the country.

    River. Lillesand. Photo: Å. Bjørke