"Water is probably the only natural resource to touch all aspects of human civilisation, from agricultural and industrial development, to cultural and religious values embedded in society," says Koichiro Matsurra, former director-general of Unesco.
As well as being vital for human society, water plays a key role in sustaining ecosystems
around the world. Unfortunately, we are entering an era of increasing freshwater scarcity due to the over-exploitation of renewable but finite resources in large parts of the world.
But much of this water use is effectively hidden from us, its final users. Each of us, on global average, uses nearly 25 times more water indirectly (about 3800 litres per person per day) in the form of products and services compared to direct water use in our households (about 150 litres per person per day).
There is growing concern around the world that the increasing population, industrialisation, urbanisation and changing lifestyles cannot be sustained if we continue on our current trajectory of water use. Instead, we must start using more water-efficient products and changing our everyday practices.
But how will we know which products are more water-efficient? And how can companies develop and market more water-efficient products? Water footprints are able to answer these questions, and are already used in environmental certification programmes such as the Australasian Environmental Product Declaration Programme, carboNZero and GreenStar. Globally, companies such as Unilever and Nestlé are using water footprint information about their products to guide their sustainability programmes.
A water footprint accounts for both the direct and indirect use of water and its associated environmental impacts during the production and use of a product or service. The concept was popularised by the Water Footprint Network in the early 2000s and more recently the International Standards Organisation (ISO) has published an ISO standard to guide water footprint studies. These initiatives, and a rapidly increasing body of academic research on water footprint methods, have begun to untangle and clarify the complexities in assessing the environmental impacts associated with water use.
