Sponge city ideas to reduce urban flooding in AsiaCEFR B2
22 Sept 2025
Adapted from Hasya Nindita, Global Voices • CC BY 3.0
Photo by Kelvin Zyteng, Unsplash
Severe urban flooding across Southeast Asia has highlighted limits in city planning and the growing risks from climate change. In March 2025 torrential rains inundated Jakarta and nearby areas, killing at least nine people and displacing 90,000. Manila and Ho Chi Minh City also experienced extreme downpours: one storm in metropolitan Manila delivered roughly five days of rain in a single hour, and heavy thunderstorms left more than a metre of water on some Ho Chi Minh streets.
China adopted the “sponge city” concept into national policy in 2013. Urban architect Yu Kongjian proposed the idea, and President Xi Jinping backed the use of natural methods to retain and purify rainwater. Unlike conventional drainage that moves water away quickly, sponge-city designs aim to absorb rainwater and release it slowly. Common measures include green roofs, rainwater storage and infiltration, sunken green spaces, permeable pavement, bioretention ponds and wetland revitalization.
Researchers say pilot projects in China have significantly improved stormwater runoff control and reformed some poor geographical conditions. In Bangkok, Yu and his team converted a former tobacco factory site into Benjakitti Forest Park; the project reduced stormwater force, filtered polluted water, and provided public space. During a 10-year rainfall event in summer 2022, much of Bangkok flooded while the park and nearby areas did not.
Despite these successes, sponge cities face controversies and practical limits. Many pilots are small and deliver local benefits rather than citywide protection. Scaling up requires cross-departmental collaboration, strong political will and wide coordination. Critics also note sponge designs may not cope with unprecedented rainfall, as seen when heavy rains in Henan in 2021 caused floods that killed 292 people in Zhengzhou, a pioneer city. Experts stress that sponge infrastructure should be combined with comprehensive drainage, emergency shelters and disaster preparedness. In Southeast Asia, high costs, aging drainage systems and limited space are extra obstacles. Indonesia announced plans to use sponge-city ideas in the new capital Nusantara in 2022, but budget cuts and uncertainty have cast doubt on timely completion.
- Key measures: green roofs, storage, permeable pavement
- Benefits: reduced runoff, water filtration, public space
- Limits: scale, cost, record storms, need for coordination
Difficult words
- sponge city — urban design that absorbs and stores rainwatersponge-city
- inundate — to cover with a large amount of waterinundated
- runoff — rainwater that moves over the ground surface
- permeable — allowing water to pass through
- infiltration — process of water entering the soil or ground
- coordination — working together between different groups or departments
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think sponge-city measures would reduce flood damage in a large city? Give reasons and refer to benefits and limits in the article.
- Which combination of measures from the article (for example, green roofs, drainage, emergency shelters) would you prioritise for a crowded coastal city? Explain your choice.
- What practical problems could prevent sponge-city ideas from scaling up in Southeast Asia? Use examples from the text (for example, cost, space, coordination).
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