The Water footprint is a term used to describe a product total use of water to produce and consume it. Using a product lifecycle approach where all the steps in the production are measured for the use of water, both directly and indirectly volume of water is calculated. The direct water usage is the volume used in processing, washing, cleaning of a final product such as when you buy a new pair of jeans.
The indirect usage is all the water consumed throughout the supply chain to grow cotton to make fibres for weaving and colouring the denim, dyes, sewing and finishing etc. Therefore, Indirect water usage is very important because it considers the hidden or ‘virtual’ water that is needed to produce goods and services. Commonly indirect water usage is considerably larger than direct use because it includes water-intensive processes such as irrigation of crops.
There are many websites that made global averages for products across their whole life cycle. The most important element to know regarding how global average volumes of water are calculated is that they are a sum of three components: blue, green and grey water footprint.
Calculated water footprint
- bluewater footprint measures water consumed from ground and surface water sources such as lakes, rivers and reservoirs
- green water footprint measures the soil such as rainwater
- the grey water footprint is the water necessary to dilute pollutants (fertilizers nitrogen), so the quality remains at tolerable standard.
The Water footprint is a quite useful tool for consumers to understand how much water it takes to produce everyday products and services. The important factor is to know where it is produced because it takes a much higher level of energy if the water is taken from a region with water shortage.
- Bluewater footprint measures water consumed from ground and surface water sources such as lakes, rivers and reservoirs
Green water footprint
- Green water footprint measures the soil such as rainwater
Grey water footprint
- Grey water footprint is the water necessary to dilute pollutants (fertilizers nitrogen), so the quality remains at tolerable standard.