World-wide the frequency and impacts of flooding exhibit a steep increasing trend1. The key drivers are the world’s population growth and the increase of socio-economic activities (development) in flood-prone areas, and society’s growing interdependency on flood protection and drainage infrastructure of which a significant part is of unknown or poor condition2, 3. It is more and more recognized that flood risk management approaches should be able to respond to changes in the natural and socio-economic environment. Moreover they should perform well under various potential futures as there is inherent uncertainty about the magnitude of the drivers of flood risk.