Using Parametric Simulation and GIS to Design a Stormwater Solution for a Chinese Sponge City

In 2013, the Chinese Central Government implemented the Sponge City Program, an initiative for cities to act as “sponges” whereby managing 60% of rainfall on-site without discharging it to local rivers and sewers. Sponge Cities simultaneously reduce flood risk, preserve the natural hydrological cycle, and create opportunities for reducing potable water demand through using collected rainwater instead of drinking water for applications such as irrigation and sanitary uses.

In 2015, the planning department for the City of Wuhan, a nominated pilot city for the Sponge City Program, engaged Adrian Smith + Gordon Gill Architecture (AS+GG) to assist in the preparation of a growth plan for 90 hectares of land directly north of the urban core. As part of the masterplan design, AS+GG suggested utilizing the Sponge City Program as a primary guiding principle for both the streetscape and building design. The project set a goal for stormwater management to manage 90% of 1:100 year 24-hour storm event on-site.

This paper details the simulation approach used in evaluating strategies to accomplish the 90% stormwater management goal. Utilizing data and geometry exported from both GIS and Rhino 3D modeling software, the team developed a custom multi-parameter simulation tool which allowed us to test various stormwater management planning scenarios. The team was able to vary strategies at a feature, parcel or district scale and the results are presented as percentages and total volumes. This workflow allowed the team to quickly adjust local design strategies to monitor compliance with the overall project goals.