The water footprint is an ...

The water footprint is an indicator of freshwater use that looks at 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 used to produce the goods and services consumed by the individual or community or produced by the business. Water use is measured in terms of water volumes consumed (evaporated or incorporated into a product) and/or polluted per unit of time. A water footprint can be calculated for a particular product, for any well-defined group of consumers (for example, an individual, family, village, city, province, state or nation) or producers (for example, a public organization, private enterprise or economic sector). The water footprint is a multi-dimensional indicator (three colors: green, blue and grey - see definitions below) geographically explicit indicator, showing not only volumes of water use and pollution, but also the locations and time of use and pollution. The WaterStat database (URL: www.waterfootprint.org/?page=files/WaterStat), a comprehensive database on water statistics maintained by the Water Footprint Network, may be of help. There you can find: - Product water footprint statistics Find here statistics on green, blue and grey water footprints of crops, derived crop products, biofuels, and farm animal products. All data are available at national and sub-national level. - National water footprint statistics Download here statistics on green, blue and grey water footprints of national production and consumption. - International virtual water flow statistics Here you find detailed statistics on international virtual water trade flows and on water savings related to international trade. - Water scarcity statistics This is the only database in the world providing data on blue water scarcity per river basin on a monthly basis. - Water pollution level statistics Download here statistics on water pollution level per river basin. [Visit: www.waterfootprint.org/?page=files/WaterStat] If you mean to carry out a water footprint assessment, which refers to the full range of activities to: (i) setting goals and scope of the assessment, (ii) quantify and locate the water footprint of a process, product, producer or consumer or to quantify in space and time the water footprint in a specified geographic area (i.e. wf accounting); (iii) assess the environmental, social and economic sustainability of this water footprint; and (iv) formulate a response strategy, then in the accounting phase it is necessary to collect factual, empirical data on water footprints with a scope and depth as defined earlier. Again, there the WaterStat database may be of help, depending on the goals and scope of the study. A comprehensive and sound set of equations exists on how to determine green, blue and grey water footprint (see Hoekstra et al., 2011). Full information on water footprint assessment can be found in the Water Footprint Assessment Manual (Hoekstra et al., 2011), freely available at: http://www.waterfootprint.org/?page=files/WaterFootprintAssessmentManual Some definitions that may help: * Blue water footprint – Volume of surface and groundwater consumed as a result of the production of a good or service. Consumption refers to the volume of freshwater used and then evaporated or incorporated into a product. It also includes water abstracted from surface or groundwater in a catchment and returned to another catchment or the sea. It is the amount of water abstracted from groundwater or surface water that does not return to the catchment from which it was withdrawn. * Green water footprint – Volume of rainwater consumed during the production process. This is particularly relevant for agricultural and forestry products (products based on crops or wood), where it refers to the total rainwater evapotranspiration (from fields and plantations) plus the water incorporated into the harvested crop or wood. * Grey water footprint – The grey water footprint of a product is an indicator of freshwater pollution that can be associated with the production of a product over its full supply chain. It is defined as the volume of freshwater that is required to assimilate the load of pollutants based on natural background concentrations and existing ambient water quality standards. It is calculated as the volume of water that is required to dilute pollutants to such an extent that the quality of the water remains above agreed water quality standards. Reference: Hoekstra, A.Y., Chapagain, A.K., Aldaya, M.M. and Mekonnen, M.M. (2011) The water footprint assessment manual: Setting the global standard, Earthscan, London, UK. Hope this helps!