Adverse social impacts can reduce the intended benefits of a project aimed to reduce flood risks, and can threaten its viability if they are severe enough. In some other cases, the diverse impacts may mutually counterbalance each other, by furthermore strengthening and amplifying the social resilience. Social changes include those associated with the phenomenon known as the social construction of reality. In the case of proposed actions that involve controversy, attitudes and perceptions toward a proposed policy change are one of the variables that must be considered in determining the significance of impacts. This research entails an analysis of public authorities strategic documents developed during the last ten years in the context of strengthening Paris flood resilience. The review highlights a clear trend to encourage citizen participation and to share responsibilities with the population. This trend does not only express a political will to apply the principle of subsidiarity and decentralise risk management, it also springs from a growing awareness among public institutions of the impact that social construction of the reality can have. Hence the communication between local governments and citizens, especially a two-ways dialogue (i.e. participatory communication), has become a keystone of resilience strategies since it facilitates mutual understanding, shared goals identification and cooperation. More and more frequently flood resilience projects entail a communication strategy or focus on communication actions. However not all these project identify clear communication objectives, target audiences or monitor communication impact. Measuring communication indicators allows decision makers to compare the costs of communication actions with the economic, environmental, social, and sanitary costs of non-action. Those metrics also help to set up clear communication objectives at the beginning of a project, to evaluate and improve management capacities, to increase transparency and stakeholder involvement during and after a project. This research is being undertaken in partnership with Veolia.