397731 - Coupled Modeling of Flood Control and Stormwater TMDL in Sponge City Construction of Zhenjiang City in China
Monday, June 4
4:00 PM - 5:30 PM
Location: Greenway AB
Jantai Kuo, Seattle – Seattle Environmental Science and Technology
Zhenjiang is one of the pilot sponge cities among the first 16 cities in 2015. The construction goals of Zhenjiang’s sponge city are (1) prevent urban flooding up to 30-year storm even and (2) improve water quality of rivers and lakes in the city to China’s surface water quality standard of Class III.
To work with the designers and landscape architects the study area is delineated into 11 drainage basins first. The layout of green and grey infrastructures in each basin are located. Then coupled hydrologic models with water quality models are built and run at various rainfall conditions. The total runoff volume and pollutant loads to each drainage basin can be obtained from the couple models. We then distribute the runoff volume and pollution load to each treatment facility including low impact development (LID) or green infrastructure (GI), inline detention, storage and treatment at outfalls. If the load is too large and the water environment capacity of the receiving water cannot hold the load, then we work with the designers to modify the layout. The modified coupled models are running again to see if the water quality standard in the receiving water can be reached. This iterative process is continued until the water quality standard is achieved. We model the capacity of the infrastructure to see if they can handle 30-year storm event. If not, then some actions must be taken to either increase the pipe size or to build up more storages. These facilities can serve for both water quantity and quality purposes.