Access to water is one of the major challenges the world is facing today. The demand for water will continue to increase as the global population grows and exerts increasing pressure on supplies. This distorted relationship between demand for water and available resources is known as water scarcity. In addition to growing water demand, on-going water pollution is likely to exacerbate water stress – which is a symptomatic consequence of scarcity – by reducing the amount of potable water. As a result of these forecasted developments, access to water over time will become unreliable in many places, leading to water insecurity. Indeed, water security was identified by the World Economic Forum (WEF) in January 2011 as one of the key risks that the world may be facing over the next 10 years.