Economic optimization of flood prevention systems in the Netherlands

After the flood disaster of 1953, the Netherlands adopted a rational approach to flood risk management with the use of protection standards determined by means of cost-benefit analysis. Due to scientific and political developments that have recently taken place, an update of the Dutch protection standards is being undertaken. One of the major priorities considered, is the need to address three issues, namely: (1) expressing the protection standards as failure probabilities of the flood defences, i.e. probabilities of breaching, instead of exceedance frequencies of water levels that is currently the case, (2) taking into account a spatial variability of those failure probabilities, and (3) considering various flooding scenarios. These aspects have been comprehensively addressed within a national flood risk analysis project, and partly considered in a numerical cost-benefit analysis approach, developed for the determination of new protection standards in the Netherlands. This paper presents an analytical economic optimization approach that makes an explicit link with all results of the national flood risk analysis project. In particular, an approach is outlined for the approximation of economically optimal design values of the failure probabilities along dyke-ring segments, which are treated as a series system of flood defences. The approach can assist in the determination of new protection standards in the Netherlands, but also in the design of flood prevention systems elsewhere. Copyright The Author(s) 2015