Sponge cities and sustainable drainage systems: sharing best practice in China and the UK

Flooding from rivers, surface water and the sea is a major hazard in many cities of the world and is expected to increase in the future due to climate change. With funding from the UK-China Urban Flooding Research Impact Programme, part of the UK-China Newton Fund, researchers and practitioners from both countries are collaborating on a project which focuses on surface water flooding and aims to enhance technical co-operation and knowledge-sharing in urban flood risk management. A comparison of current approaches to urban flood risk management in China and the UK is presented, and a case study of the benefits of Sponge City construction in the city of Wuhan, China is used by way of demonstration. Interventions to increase infiltration rates and on-site storage prove most effective for the 1-year return period, but have a more limited effect as flood event rarity increases. The paper discusses how similar results have been found in the UK for case studies of Sustainable Drainage Systems (SuDS), either installed in new urban developments or retrofitted in older ones. These studies also recognise the multiple benefits brought by the installation of green infrastructure, particularly in terms of community engagement and well-being.