Flood damages result from interacting hydrological and social processes. System dynamics models can describe these interactions numerically, generating insights into possible future impacts. This work analyses the interconnections between floods, community-level public flood risk management, and household-level private flood preparedness. A system dynamics model represents the coupled-interactions between household flood damages, public measures at the community level that reduce exposure to flooding, and private measures at the household level that reduce vulnerability to floods. These interactions are conceptualized based on Protection Motivation Theory and are calibrated to empirical data of 3770 household survey responses on flood risk perceptions and preparedness from various locations in Austria. Model scenarios show that continual and increased proactive investments in public measures minimise future damages. However, because public measures might meet financial, technical or social limitations, private household measures could step in to reduce vulnerability. Flood experience increases household preparedness measures. Modelling shows how these reduce vulnerability shortly after flooding. This is particularly valuable in the time-period before public measures that reduce exposure have been implemented. However, household measures decay rapidly, suggesting the need to promote their implementation (ideally prior to flooding), and ensure their continual functioning through support for their operation and maintenance.