Optimizing LID Practices in the Genoa Urban Drainage System Based on the Community's Call for Action Through Participatory Mapping

This paper presents a novel methodology for optimizing installation of low impact development practices (LIDs) in an urban hydrological catchment. This methodology helps stakeholders in deciding on what kind and area of LID must be installed in each sub-catchment to attenuate pluvial flooding as a result of intense rain events. The main novelty consists of the community's engagement in the optimization process, by means of an additional objective function to consider the community's appreciation for the choice of LIDs. The methodology is applied to a real case study, i.e., a part of the urban drainage system (UDS) of Genoa, which is frequently plagued by pluvial flooding events that annoy the community. Following a survey of community preferences, the results of which were collected by means of participatory mapping, the methodology yields a Pareto front of trade-off solutions between installation costs, pluvial flooding volumes, and community satisfaction. From the front, stakeholders can select the ultimate solution based on budget constraints and/or on expected joint performance in terms of flood attenuation and community satisfaction.