Many coastal cities are experiencing growing risk to hydrological hazards through the combination of uncontrolled urban development and exposure to natural phenomena linked to climate change, including rising sea levels, intensified storms, and amplified storm surges. This growing risk is particularly acute in Asian coastal mega-cities, many of which have yet to develop adequate adaptation policies to address plausible impacts of climate change. In this analysis, we review how Hong Kong and Singapore, two of the most affluent coastal cities in East Asia, have initiated many flood mitigation strategies policies that have allowed them to reduce the impacts flooding. These strategies, once relying largely on building flood control structures, have now evolved to include holistic flood risk management approaches that include socio-economic factors. Arguably these two success stories provide inspiration for other coastal Asian cities. However, as climate change and uncontrolled development are likely to increase urban flooding in the future, general improvements could be made to improve knowledge transfer: e.g., develop means to work across policy silos and strike compromises between conflicting sectoral responsibilities, and develop long-term integrated strategies using planning tools and practices to address growing risk. While knowledge transfer cannot be direct because of different geographical settings, socio-economic situations, and political situations, we encourage governments to look beyond engineering-based flood control structures as to develop flood governance programs.

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