Planning for resilient cities requires an evidence-based understanding of flood risk and the involvement of stakeholders and local actors. The paper addresses research developed within the URCA!—Urban Resilience to Climate Change: to activate the participatory mapping and decision support tool for enhancing sustainable urban drainage—project. A top-down/bottom-up participatory and flexible methodology for the conception of participatory mapping aimed at the planning and installation of sustainable urban drainage systems (SUDS) on the territory is then developed. The innovative methodology is applied and tested in the case study of the Sampierdarena district in Genoa, northern Italy. This research paper illustrates the development of a participatory map (Pmap) that can support the implementation of SUDS as mitigation/adaptation strategies, integrating technical assessment and containing community visions and expectations. Findings concerning the connections between proposed SUDS locations and their frequencies confirm the relevance of the commercial area and the main traffic lanes along, confirming that all zones characterized by intense vehicular and pedestrian flow are suitable for SUDS as a solution to contribute to urban flood resilience. The georeferenced and intergenerational Pmap may be integrated into a decision support system to be developed as a guidance tool for the public administration.