Water is essential for human wellbeing in many ways. We need water for drinking, cleaning, food production and industrial purposes. Today the pressure on the existing freshwater resources is such that more than 25 % of the world’s rivers run dry before reaching the oceans – and the demand for freshwater is growing. The fact that many river basins are shared between countries is increasingly regarded as a potential cause of conflict. The increasing pressure on existing freshwater resources calls for water scarce technologies in agriculture and industry as well as in water supply and sanitation.