Siting green stormwater infrastructure in a neighbourhood to maximise secondary benefits: lessons learned from a pilot project

When siting green stormwater infrastructure (GSI), cities do not respond only to technical and regulatory requirements; they also strive to maximise environmental, aesthetic and social benefits. To help cities optimise the siting of GSI in the context of climate change, we developed a participatory decision support tool. Applied to a neighbourhood, this tool identified only a few sites where GSI would yield all secondary benefits and reduce climate change vulnerability. In the light of the need for large-scale implementation of GSI in cities, this finding raises the following questions: How can the potential benefits provided by a site be best identified? Are there potential synergies or antagonisms between benefits? How do they relate to vulnerability? Can a participatory decision-making process involving local stakeholders improve this process? Informed by the existing literature on balancing ecosystem services and vulnerability, these questions are addressed within a broader perspective of landscape design and urban planning.