Alternative fuels - the water requirements

While I've long been suspicious about the true energy efficiency of "alternative fuels," I hadn't considered the efficiency with respect to water consumption. As major population centers far from fresh water continue to grow, efficient use of water will be a huge issue globally.

While burning food (ala corn ethanol) never seemed like a great idea to me, consuming a bunch of precious water to boot seems like an even bigger problem:

http://www.vwrrc.vt.edu/watercooler.html