The Trienger Dorfbach in the canton of Lucerne and its tributaries pose a major flood risk. We are managing the comprehensive participation process for a third-party office's flood control and revitalization project at the preliminary design and construction project stages. The participation concept we developed allows the population and those directly affected to be involved in the planning process for the preliminary design and construction project, to be heard, and to have their ideas taken into account in the planning of the implementation variant.