Adapting to the impacts of climate change and urban growth in urban flood management requires approaches, which mitigate the flood risk and provide sustainable solutions. A combination of local drainage systems and water retention in public spaces may provide an appropriate strategy to cope with present and future pressures on the urban drainage infrastructure. To implement these small-scale hydrological systems in catchment models, novel hydrological modelling approaches are required that can handle a large number of spatially distributed measures. This paper presents the enhancement of a model system and the application for an urban catchment in Hamburg, Germany. The efficiency study of decentralised systems was conducted on the basis of climate change and urban growth scenarios. The results demonstrate the potential of sustainable drainage systems and multipurpose retention spaces for flood peak mitigation.
