Drivers and Barriers to Multi-Layered Flood Risk Management: a Comparative Study of Dutch and Us Practice (PAP014831)
Kim Anema, Jessica Ludy, B. Gersonius, Chris Zevenbergen
Flood resilient societies through community preparedness
After decades of primary focus on protection, the 2009 Dutch National Water Plan introduced Multi-Layered Safety (MLS) as national policy that also integrates spatial planning and emergency management into flood risk management. Around the same time, a number of regions in the US started exploring ?multiple lines of defense? and implementing non-structural flood risk management programs. It proves to be difficult, however, to implement MLS in practice and to (optimally) balance investments across all three safety layers.The purpose of this paper is to identify and compare drivers and barriers to the implementation of MLS in Dutch and US practice. In total, six case studies have been analysed and compared: three in the Netherlands (Kampen, Dordrecht and Almere) and three in the US (Valmeyer, Stockton and Natomas). The case study analysis focused on the participative process and development of the local strategy for flood risk management, the role of each safety layer within the strategy, and the rationale behind the strategy. In the analysis, specific attention was given to geographical, social and political contexts.Drivers for implementing prevention measures (layer 2) were mostly tied to environmental regulations, social values and aesthetics. In Kampen and Almere, the region wanted to preserve the aesthetic and environmental quality that they felt would have been destroyed by simply building a large dike. In Natomas, the environmental stipulations of the Endangered Species Act actually required that the communities protect land for habitat values by purchasing conservation easements that would ensure land would be permanently in nature.Investments in preparedness (layer 3) were influenced by geographical and physical factors. In Almere and Natomas, the presence of deep and densely populated polders demanded sufficient evacuation routes. Regulatory factors drove preparedness measures in both the Netherlands and the US.