The biggest users of water on the planet are agriculture and food production. According to a study by the Stockholm International Water Institute, their share of all water consumption adds up to 70%. On the other hand, as much as half of the water used by agriculture is wasted on account of evaporation and inefficient use.

The water footprint was introduced at the University of Twente in the Netherlands in 2002. The concept itself is still considered to be evolving and not without dispute. The calculation methods are not so far unambiguous and established.

The standardization is in its developing stages. However, some environmental stakeholders have already been visioning a “Water Stewardship Council” along the lines of certifying seafood and forests.

Forest certification may expand further in the direction of including carbon and water footprints. European forest industries are actively involved in these networks in order to avoid the controversy the forest certification has resulted in at times.

There are many ways to estimate
The water footprint can be calculated for example for a company, a product, a country or a human being. The human water footprint for the whole world amounts to about 1200 litres on average. Obviously, the scope of variety is considerable.

The water footprint can also be divided into a direct and an indirect one. The indirect footprint consists of the amount of water that the raw materials of the product contain.

The operational footprint is the footprint caused by manufacturing of the product or service. This can be divided into the footprints at the beginning and the end of the production chain.

Where and when water is used defines the time and place dimensions of the footprint. International trade policy may hence have an effect in domestic production and usage of water, even in countries with abundant water reserves, such as Finland.

Both the domestic footprint as well as the one made in other countries affects a country’s water footprint: The virtual footprint consists of water, which is immersed in exported and imported goods.

The water footprint can also be divided into green, blue and grey water footprint. Green is the rain water, blue originates in waterways and grey is water discharged from the production.

There is room for interpretations
The water footprint is sometimes used in a simplistic way. As an example, the Water Footprint Network has calculated the water footprint for a cup of coffee as being 140 litres, a kilo of beef 16,000 litres and a cotton t-shirt as 2,700 litres.

The forest industries’ water footprint can be exaggerated at the forest end of the production chain. This is due to evapotranspiration, which means evaporation of water in the forest, which surprisingly is considered as a problem for the forest sector although the phenomenon is completely natural.

The WFN calculates a single A4 sheet of paper weighing 80 grams per square meter as having a green water footprint of ten litres. On top of this come the blue footprint of the production as well as they grey one. The WFN estimates the total water footprint of an A4 sheet as being between 2–30 litres.

Numerous forest sector stakeholders have disapproved of these kinds of simple estimates. It is said, that a single figure does not take into consideration the many services and products forests provide, such as the water purification effect of forests. The method does not seem to distinguish between plantations, natural forests, vegetation zones nor various tree and plant species.

It remains to be seen how big a question the water footprint will turn out to be. Even if the Finnish forests’ and forest industries’ footprint seems to be very favorable and both water and forest resources are abundant, the evolving process may bring surprises about, and it pays to take this into consideration and to get involved.

By Kai Lintunen



Stockholm International Water Institute
Water Footprint Network