Water Footprint Assessment (WFA) for better water governance and sustainable development

Increasing pressure on the Earth's freshwater resources resulting from growing water consumption and pollution, in combination with the impacts of climate change, has led to widely accepted recognition of the centrality of freshwater in sustainable development and the critical need for improved water governance. Currently, more than 2.7 billion inhabitants in about 200 basins live with severe water scarcity during at least 1 month of the year [20]. Water scarcity and high water pollution levels can result in poor access to water for meeting basic human needs, increased water risk for companies and environmental degradation. While these problems have been well documented and are gaining increased attention, a clear and consistent approach addressing the use of water throughout the value chain, from primary producer to consumer and within river basins, has been lacking. To better understand the linkages between humanity's productive activities and this growing pressure on the world's freshwater resources, the water footprint and subsequently, Water Footprint Assessment (WFA) were developed to measure the amount of water consumed and the pollution assimilation capacity used throughout a product's value chain and to assess its sustainability within both the local and global context [18]. The water footprint is an indicator that can be used to measure the direct and indirect water use (or the virtual water content) of a product, a facility, an organisation, e.g., a company, or a sector. The water footprint can also be applied to a geographic area, e.g., a river basin or nation, or an individual consumer or group of consumers. By considering the linkages between consumer goods and their water footprint, a new understanding of the processes that drive changes imposed on freshwater ecosystems is gained. By providing a structured and consistent way to measure water use and pollution throughout the value chain and across different scales, the water footprint provides a common language that supports dialogue between the range of stakeholders contributing to and resolving unsustainable water use. The four-step process of WFA – setting goal and scope, water footprint accounting, sustainability assessment and response formulation – clarifies the environmental sustainability, economic efficiency and social equitability of water use and prioritises strategic actions. The sustainability assessment identifies hotspots where water use is violating sustainability criteria, where efficiency gains can be