Integrated urban flood design in the United States and the Netherlands

Spatial design integrates social, cultural, economic, and political perspectives with natural site conditions and man-made construction to plan for sustainable urban development. The current flood-risk-related challenges induced by climate change place pressure on designing cities in which both natural and man-made conditions can be imbalanced. Creating a purely engineered line of flood defense to restore this balance does not always work. The idea of living more closely with water includes the discipline of spatial design more into flood risk management than the current dominant paradigm. Following the probability approach defined as risk = probability × consequences, the current Dutch paradigm is focused on reducing the probability with dikes; the United States focuses on reduction of consequences by evacuation and recovery. This chapter focuses on urban design and planning strategies for reducing flood risk not just by a flood defense line such as a dike, but also reducing risk by means of urban development behind the dike. Integrated urban flood design must integrate site-built environment characteristics and natural systems, and simultaneously solve challenges posed by hazards. Effective design, therefore, must be conducted on the basis of hydraulic engineering knowledge, leading to spatial designs that introduce resilient urban qualities. Two cases for this approach are presented and compared: Vlissingen, the Netherlands and Galveston, Texas, United States.