Integrated stormwater inflow control for sewers and green structures in urban landscapes

Cities increasingly use real-time control of combined sewer systems and green infrastructure to decrease emissions to surface waters, and incorporate infrastructure into the urban landscape to reduce flooding from short, intense rainfall events called cloudbursts, which can cause flash flooding. Inspired by the ‘smart cities’ agenda, we propose the use of integrated stormwater inflow control to dynamically activate cloudburst conveyance infrastructure in the urban landscape as well as green storage elements more often than originally intended. This control facilitates synergy between sewers, green infrastructure and the urban landscape, and has lower environmental impacts than isolated control approaches. A simulated, yet realistic, case study in Copenhagen, Denmark, shows that combined sewage emissions can be eliminated or reduced substantially in this manner. Other potential benefits include increasing amenity value and educating citizens, for example. The results suggest that the proposed control concept potentially provides a viable path towards more resilient, liveable and sustainable cities. Real-time control of combined sewer systems and green infrastructure can be used to reduce flooding. In this Perspective, the authors simulated the use of integrated stormwater inflow control to dynamically activate infrastructure in Copenhagen, Denmark, to substantially reduce combined sewage emissions.