The determinants of private flood mitigation measures in Germany - Evidence from a nationwide survey

•National household survey on private flood mitigation in Germany (N > 4200).•Flood mitigation increases with damage experience and damage expectations.•Climate change implies a mitigation probability increase of more than 10%-points.•Households expecting insurance coverage do not reduce their mitigation efforts.•Charity hazard is observed for risk averse and highly educated heads of households.

Public flood protection cannot eliminate totally the risk of flooding. Hence, private mitigation measures which proactively protect homes from being flooded or reduce flood damage are an essential part of modern flood risk management. This study analyses private flood mitigation measures among German households. The final data set covers more than 4200 households from all parts of the country, including flood plains as well as areas which are typically not at a high risk of riverine flooding. The results suggest that the propensity to mitigate flood damage increases i.a. with past damage experience and damage expectations for the future. The latter effect can be interpreted as a 'climate adaptation signal' in the flood mitigation behaviour. All other factors remaining equal, a strong belief in a climate-change-induced increase of personal flood damage in the next decades correlates with an increase of the probability of flood mitigation by more than 10 percentage points. Moreover, empirical evidence for moral hazard in the flood mitigation behaviour cannot be observed. Households expecting insurance coverage do not reduce their mitigation efforts. Likewise, the expectation of government relief payments hinders mitigation only for some groups of households.