EN: The lack of water is already a major problem in certain areas of the world and as the world's population and living standards increase, the situation will aggravate. An interview in the ZEIT (german) with the CEO and president of the advisory board of Nestlé Peter Brabeck-Letmathe gives more insight into that topic. Brabeck-Letmathe explains that water should be considered as a fossil resource and why it does not make sense in many parts of the world to produce biofuels. The reason for this is that the crops necessary to produce biofuels require the water (and other resources) that would otherwise be used to grow food crops. It is mentioned that agriculture consumes 93% of all fresh water used and that one vegetable calorie needs around 50 liters in production while one animal calorie needs 500 liters. Brabeck-Letmathe proposes less wasteful technologies, genetic engineering and higher water prices to improve the situation.
I assume a reduced consumption of animal products and the industrial usage of organisms that naturally uses less water would also help. Algae like Spirulina might be candidates as they require less water than common crops. If you have a better/newer/contradicting source please let me know. More proposals?