Water footprint and ISO 14046:2014 water footprint, two different methodologies for quantifying water use that provide valuable information for rational use. Among the services offered by inèdit, there is one to quantify them. With the proximity of World Water Day (March 22), let’s take the opportunity to explain what each one calculates and how they differ.

Water footprint

The water footprint is an indicator that helps us understand how our choices when consuming or producing affect natural resources. It informs us how much water is needed to carry out activities such as producing the food we consume every day or the clothes we wear, and to indicate the pressure we exert on freshwater natural resources. It can be calculated for an individual, a process, the value chain of a product, or for a company, a river basin, or a country. The concept of water footprint was born in 2002 by Arjen Y. Hoekstra, a professor at the University of Twente in the Netherlands, and founder, in 2008, of the Water Footprint Network.

This indicator provides very powerful information for companies to understand the risks of the business in relation to water, for governments to understand the role of water in the economy and the dependence on this resource, and for consumers to know how much water is behind the products they use. In addition, it is a starting point to promote strategic actions towards sustainable, efficient, and equitable water use.

According to the focus of the Water Footprint Network, the water footprint can be divided into three types of indicators: the green water footprint, which is the water from precipitation that is stored in the roots, which incorporate the plants and evaporates; blue water footprint, related to the consumption of freshwater, and grey water footprint, which is the amount of freshwater needed to dilute pollution and comply with specific water quality standards.

The water footprint reflects the impact of humans on global freshwater resources and provides a knowledge base for formulating strategies to minimize it.

ISO 14046:2014 Water Footprint

The ISO 14046:2014 water footprint is a global indicator of consumption and changes in the quality of water resources to produce goods and services indirectly by the consumer, the producer, and the marketer. It follows ISO 14046 and is based on Life Cycle Assessment (LCA). Unlike the water footprint, it does not only account for the volume of water consumed but evaluates the possible environmental impacts linked to this water consumption through various indicators.

How do water footprint and ISO 14046:2014 water footprint differ?

While the water footprint has a volumetric approach, the ISO 14046:2014 water footprint has an environmental impact approach. The former is well established and, being very easy to interpret, has always served to raise awareness about the actual use of the resource behind a product. The ISO 14046:2014 water footprint, on the other hand, evaluates the impacts in a region caused by the use and degradation of water. Thus, the impacts on the environment, human health, and on water consumed and changes in its quality related to a product, process, or organization are evaluated. It is a more exhaustive and complex analysis, and it requires familiarity with LCA methodology to interpret the results.

These are two compatible tools. The analysis of the water footprint can serve to raise awareness and also as a tool for regional water evaluation and management; in contrast, the ISO 14046:2014 water footprint is more useful for environmental sustainability studies of a product or organization.