The world population is expected to increase to over 9 billion by 2050, 34% higher than today (United Nations, 2012). Alarmingly, most of this population increase will occur in developing countries where access to water for agriculture and domestic purposes is already under stress, and 2.3 billion people lack access to safe drinking water (IWMI, 2007). Until recently, water was an infinite resource because there were fewer than half the current number of people on the planet and they were less wealthy than today. Consequently, they consumed fewer calories and ate less meat, requiring a third of the volume of water we presently take from rivers. Today, the competition for water is much more intense as the consumption of water-thirsty meat and vegetables is rising. Increasing competition for water from industry, urbanization, biofuel crops and water-reliant food items has further exacerbated the water stress problems.