Are sponge cities the solution to China's growing urban flooding problems?

Nature-based solutions have been promoted as a sustainable solution for urban stormwater management and they are currently adopted at an unprecedented speed and scale to build sponge cities in China, with a primary aim to solving urban flood problems. However, there are limits to how much rainfall sponge cities can absorb, hence, they are unlikely to be a panacea for flooding problems in cities. We argue that bottom-up community-based measures are essential part of the intervention development framework that is required to transform sponge cities into flood resilient cities. This community-based approach can effectively build on the distinctive and unique feature of Chinese cities, that is, the prevalence of gated communities, which provides a solid foundation for implementing community-based measures for flood management. A range of such community-based measures including resilience mapping, property-based resistant and resilient measures, flood insurance, and social resilience building are discussed. Flood resilience building does not just mean investments in gray-green-blue infrastructure, it requires social transformation toward flood resilient communities. This article provides a roadmap for the next stage development of sponge cities which plays a key role in coping with extreme storm events and adapting to climate change in cities. This article is categorized under: Engineering Water > Sustainable Engineering of Water Engineering Water > Planning Water Science of Water > Water Extremes

Automated summary

Nature-based solutions, such as sponge cities, have been advocated as a sustainable approach to urban stormwater management. However, there are limitations to their ability to absorb rainfall, making them insufficient in solving flooding problems in cities. This article argues that community-based measures are essential to transforming sponge cities into flood resilient cities. The prevalence of gated communities in Chinese cities provides a solid foundation for implementing these measures. The article discusses various community-based approaches, including resilience mapping, property-based measures, flood insurance, and social resilience building. It emphasizes the need for social transformation towards flood resilient communities.