What's Your Waterprint?

(Originally posted on waterefficiency.net)

By Elizabeth Cutright
Editor
Water Efficiency

Did you know that it takes 30 gallons of water to produce one cup of coffee? And that half-pound steak you had for dinner required 774 gallons of water to get from the ranch to your table. Where do these numbers come from, and what do they mean? These total refer to water footprints, and the totals themselves are calculated by adding up the total amount of freshwater used to create a particular item or support a specific activity.
The idea of a water footprint was first introduced by A.Y. Hoekstra and P.Q. Hung from UNESCO-IHE in 2002. Hoekstra and Hung believed that one should total up both the direct and indirect water used by a particular entity—consumer, community, or commercial/industrial enterprise—so that total amount of freshwater needed to produce the goods and services consumed by that entity could be measured. These measurements include the actual water in the product, along with all the virtual water embedded in every action associated with the cultivation, collection, and delivery of that item.
The water footprint of foodstuffs, for example, include actions by the farmer, food processor, retailer, and consumer. These tasks that consume actual water include growing, harvesting, delivering, or purchasing a food item. But the cultivation and exportation of food brings with it a variety of embedded water costs, including those associated with the byproducts created by food cultivation (agricultural runoff for example), as well as the items and actions necessary for the production and distribution of food. (This includes fertilizers and insecticides, as well as the fuel required for transportation and the packaging that keeps the food safe and fresh as it travels from field to home.)
But what does water footprinting (or virtual water) have to do with water efficiency? Well, as I stated in an editorial on the subject last year, entitled “How Much Is That Droplet in the Window, “efficiency depends upon the ratio of work expended to benefit received. Many times, there are a variety of methods available to achieve a particular end, and knowing which of those many options is less water-intensive can make a big difference. As I’ve stated before, I believe that by redefining how we measure the value of water—by monitoring our “water footprint” and keeping track of our virtual water costs—we can harness new tools to help us protect, and efficiently manage, our resources.”
In keeping with our commitment to provide you with all the information and tools necessary to manage your water resources, I’m excited about our latest venture, the first Water Efficiency iPhone application: Waterprint. Waterprint is a free application that lists and calculates how much water is imbedded in a variety of activities and products, including what you wear, eat, and drink. You can learn more about the application at the Waterprint Web site, and it’s available now at the App Store. If you’re iPhone enabled, please take it for a spin and let us know what you think. We plan to continue to update and improve the application, and, as always, your feedback is a valuable resource for us.
For more on the origins of the water footprint concept (as well as a list of the many water footprint totals we’ve included in our application), go to: www.waterfootprint.org.