The Water Nexus project is an interuniversity research platform led by UCLouvain with the aim to develop a water strategy for the Belgian development aid. The University of Antwerp supported the development and analysis of a survey with actors in Belgium and the Belgian partner countries on the barriers and opportunities for a forthcoming water strategy. We also compared the water strategies of other countries and international organisations. Finally, we reviewed the potential of public-private participation in sanitation and waste water treatment in developing countries.