Trial by typhoon shows city's resilience

Over 40 percent of the city's built-up area met sponge city standards by the end of 2025, with target coverage reaching 50 to 60 percent in suburban new towns, according to officials. By 2030, the figure is expected to reach 80 percent in the city's built-up area.

Heping Park in Hongkou district is an example of this approach after its central lake was transformed into a retention basin. Pedestrian walkways were covered in permeable paving, while wet stretches of land were covered in vegetation to collect, filter and move surface water.

"Normally, our lake water level is maintained between 2.3 and 2.6 meters," He Yizhi, director of Hongkou district greening management center, explained to Shanghai Morning Post.

"During heavy rain, the storage level can rise to 2.8 meters, absorbing 8,787 cubic meters of runoff. When extreme weather requires park closure, the storage level can expand to 3.1 meters, providing 17,400 cubic meters of emergency retention capacity to protect surrounding residential blocks."

Heping Park used its lake as a temporary flood basin to help nearby streets drain faster. While closed for safety reasons, park workers pumped excess rainwater from surrounding roads into the park's central lake, relieving pressure on the city's drainage system.

Wu said Shanghai's priority is to create functional spatial pathways and ecological capacity for water management while safeguarding its core economic operations.

To forge true climate resilience, Wu said a strategy should take into account infrastructure, technology, ecology and emergency management.

This requires urban renewal to include localized sponge-city water retention, integrate local pipe networks with regional river systems for multi-scale drainage, utilize advanced technologies including artificial intelligence for predictive forecasting and dynamic scheduling, and establish designated surface runoff pathways to protect below-ground infrastructure during extreme downpours.

"Shanghai's most urgent task is to genuinely organize urban renewal, sponge city construction, drainage networks, river system management, watershed flood control, and intelligent scheduling into a complete integrated system," Wu said.

zhengzheng@chinadaily.com.cn