It’s an old joke, and it’s wrong: multinational brewing giant SABMiller has estimated that producing a liter of beer requires 45 to 155 liters of water, depending on the location of the brewery. In the face of the growing perception of water supply shortages, companies around the world are finding themselves under pressure from shareholders, the public, and regulators to account for their water use, that is, their “water footprint”. A recent article from National Geographic even asks if a Water Footprint label will become as ubiquitous as EnergyStar (TM) labels have become for energy efficiency. But who would certify a Water Footprint, and how would it be measured – only consumptive use of the manufactured product, or the entire supply chain and product disposal?
As I’ve noted previously, there are several tools out there for companies to use to calculate their water footprint and evaluate their water risks:
- The Global Water Tool produced by the World Business Council for Sustainable Development, designed for multinational corporations,
- Collecting the Drops, produced by the Global Environmental Management Initiative to help inventory the water use of individual facilities, and
- McKinsey’s article on corporate global water footprints, along with their economic framework to support decision-making, entitled Charting our Water Future (also see their related climate change site)
For the water footprint of individuals, a new resource is H2O Conserve, a program of ICCR, GRACE, Food & Water Watch, and the Johns Hopkins University Center for a Livable Future. H2O Conserve is an online water conservation information center that includes the H2O Calculator. Using it, I estimated that my family uses about 800 gpd/person, about two-thirds the US National average use of approximately 1200 gpd/person. The worst offenders in our household are the dishwasher (which we use a lot) and a non-conserving showerhead (mea culpa). The site has some great K-12 teaching resources, like lesson plans and resources (Thanks to R. Vazirani for the post re: H2O Conserve in the Water Footprint group over at LinkedIn).
Other water-footprint calculators for individuals include :
1414 CDT, Jan 6, 2010: Added a link to SABMiller’s water footprint report — ddw