The water footprint concept was introduced in 2002 by A.Y. Hoekstra from UNESCO-IHE as an alternative indicator of water use.[2]. The concept was refined and accounting methods were established with a series of publications from two lead authors A.K. Chapagain and A.Y. Hoekstra from the UNESCO-IHE Institute for Water Education, now at WWF-UK and University of Twente respectively. The most elaborate publications on how to estimate water footprints are a 2004-report on the 'Water footprint of nations' from UNESCO-IHE [3] and the 2008-book Globalization of Water by A.Y. Hoekstra and A.K. Chapagain, published by Blackwell, 2008. Cooperation between global leading institutions in the field has led to the establishment of the Water Footprint Network in 2008 that aims to coordinate efforts to further develop and disseminate knowledge on water footprint concepts, methods and tools.