Modelling the potential damage-reducing benefits of flood warnings using European cases

Flood warning systems are now centre-stage in flood risk management strategies in Europe. This is due to advances in flood forecasting and the rapid communication of flood risk information, coupled with a growing understanding that communities need to find better ways of co-existing with rivers and the realization that structural flood defences are insufficient on their own to prevent flooding. However, not enough is known about the potential and actual benefits of flood warnings for avoiding property damages. This paper presents an extended approach to the estimation of potential flood damage reduction benefits of flood warnings for fluvial and tidal floods, drawing upon research completed for the European Commission’s Floodsite project. Its aim is to demonstrate the potential economic benefits of coupling flood warnings to a combination of structural and non-structural flood risk management measures. Previous research in this area is critiqued, including that which suggests that flood warnings are futile, and the features, strengths and weaknesses of the extended approach are presented and discussed. Two case studies, a national-level (England and Wales) and a local-level (Grimma, southeastern Germany) assessment of flood damage-saving potential, are presented to illustrate the new approach. Although a number of data quality issues need addressing, the model outputs and estimations of potential damage savings may be used to make wise decisions about investment in flood warning systems, and to identify those areas, such as public flood risk awareness, that need attention to achieve the full scope of potential benefits in practice.