Mitigating Urban Flood Using Green Stormwater Infrastructure

Project Title: Mitigating Urban Flood Using Green Stormwater Infrastructure
Landscape Architect: Seattle Environmental Science and Technology Inc.
Category: Research, Analysis and Planning
Location: Zhenjiang, China
Green Stormwater Infrastructure (GSI) has been used worldwide for stormwater management. However, questions remain to many landscape and stormwater professionals if GSI can mitigate large storm events by preventing urban flooding? The Jianger Neighborhood Sponge City Retrofit Project in Zhenjiang provides a unique landscape-civil engineering integrated approach using GSI to mitigate flooding in a low-income neighborhood (1.9 ha) that has suffered flooding on an annual basis.

The goals of this project went beyond minimizing flood impacts up to the 30-year storm event, but also used our team’s landscape designs + N approach to retrofit the neighborhood in to healthy climate resilient places with N elements (energy conservation, utilities upgrades, accessible parking and urban farming).  

The design process was iterative. Hydrologic models were used to guide the landscape design and modified based on the feedback from our engineers. The project was completed in 2016. The monitoring data showed that 98% of runoff remained onsite. The neighborhood has not flooded since 2016 even after experiencing three storms events that exceeded 100 mm/d. 

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