Practical Sustainability Strategies, 2nd Edition

CHAPTER 23Water Footprint

OVERVIEW

A.Y. Hoekstra introduced the water footprint concept in 2002; it has been developed as an indicator, used to express the total amount of volume of fresh water consumed to produce a particular good, or to provide a service.

The main objective of assessing the water footprint of goods is to analyze how their production is affecting water resources (and pollution), and how these processes can be more sustainable (from a water perspective).

The water footprint is composed of three components: green, blue, and gray water footprint. The blue water represents the volume of water, which is withdrawn from surface (sea, lake, and river) or grand-water, and does not return to the same basin of catchment, or to the sea.

The green water is the rainwater, the soil moisture adsorbed, and the evapotranspiration of the plant. As it is easy to imagine this component of water footprint is of particular relevance toward the agriculture sector in comparison with the industry sector (just in the case in which they have green roof, but, even in that case, is usually not significant).

The last component of the water footprint, the gray water, represents the amount of water, which is necessary to dilute the load of pollutants/emitted substance from the production chain, in order to make them harmless.

The water footprint can be expressed in a variety of ways, according to what is most relevant to underline in the assessment. For instance, it can be expressed as water ...