kongjian yu's sponge cities show how urban design adapts to climate change

Kongjian Yu’s Legacy in Urban Design

Landscape architect Kongjian Yu, who passed away on September 23rd, 2025, in a small plane crash in Brazil at the age of 62, became globally renowned for pioneering the ‘sponge city’ concept, a design framework that uses natural landscapes and nature-based solutions to catch, store, and purify urban water.

As cities around the world struggle with flooding, water scarcity, and the consequences of rapid urbanization, the Chinese architect and his practice, Turenscape, spent three decades shaping an alternative. His vision of the sponge city has shifted from an academic concept to national policy in China and an international model for climate resilience.

The concept, officially adopted into the Chinese government’s urban development policy in 2014, was projected to influence more than 80% of mid- to large-sized Chinese cities by the end of the decade. Yu’s work combined scientific research with practical design, demonstrating how ecological infrastructure can mitigate floods, recharge groundwater, and support biodiversity, while simultaneously creating public green spaces.

Qian’an Sanlihe River Ecological Corridor | images by Turenscape, unless stated otherwise

Scaling Sponge Cities: From Regions to Neighborhoods

The sponge city strategy operates across three scales. At the macro scale, national and regional planning focuses on protecting ecological water processes and maintaining a balance between human activity and natural hydrology. Large-scale projects safeguard rivers, wetlands, and floodplains, forming ecological security patterns that guide urban expansion and infrastructure development. Regions such as Beijing, Taizhou, and Weihai have incorporated these principles into regional planning, emphasizing water-sensitive ecological infrastructure.

At the medium scale, sponge city principles guide urban development across several to tens of square kilometers. Planners integrate green infrastructure with the existing urban fabric, delineate system boundaries, and establish regulatory and design guidelines. Notable examples include Haikou’s Meishe River Greenway, Qian’an’s Sanlihe River Ecological Corridor, and Nanchang Fish Tail Park, where flood mitigation, habitat restoration, and public recreation coexist within functioning urban ecosystems.

At the micro scale, communities and households participate in stormwater management. Green roofs, permeable courtyards, and other small-scale ecological infrastructure convert residential land into functional ‘green sponges.’ Studies suggest that converting even 20% of residential land into green infrastructure can significantly reduce urban flooding, demonstrating that effective water management is both a citywide and neighborhood-level effort.

Jinhua Yanweizhou Park

from theory to prototypes

The seeds of the sponge city idea were planted in the mid-1990s, when Yu’s research at Harvard and later in China proposed integrating wetlands and floodplains into urban form. In 1998, he introduced the idea of security patterns in planning, framing rivers and wetlands as infrastructures of safety. These ideas materialized in early 2000s projects like the Beijing Olympic Green (later Houtan Park) and stormwater systems in Shenyang, which tested wetlands as green sponges that could mitigate both droughts and floods.

By 2005, Yu had consolidated the idea of ecological stormwater management, advocating for what he called ‘negative planning’, designing with natural processes in mind.

Fish Tail Park

Milestones: projects that proved the concept

Constructed for the 2010 Shanghai Expo, Houtan Park quickly became a flagship example, featuring a riverside wetland that filtered polluted water and doubled as a public park, later winning the American Society of Landscape Architects’ Award of Excellence. Soon after, the Harbin Qunli Stormwater Park transformed 34 hectares of wetlands into a living sponge that could absorb urban runoff while creating biodiverse habitats.

When devastating floods hit Beijing in 2012, Yu publicly criticized the reliance on grey infrastructure and used national television to call for sponge cities. His advocacy helped pave the way for China’s State Council to launch the Sponge City Program in 2014, rolling out pilot projects across the country.

Between 2014 and 2018, sponge city pilots spread across dozens of Chinese cities. Yu’s firm Turenscape refined the approach with projects such as the Sanya Dong’an Wetlands and Beijing’s Olympic Forest Park, introducing the modular Life Cells concept, networks of ponds, terraces, and wetlands acting as green infrastructure at different urban scales.

The International Federation of Landscape Architects awarded sponge city projects for ecological design, while UN Habitat and the World Bank cited them as models for climate-adaptive planning. By 2018, sponge cities had become a central pillar of China’s urban strategy.

Turenscape transformed a disused 126-acre waterscape into a floating forest