Regulation of Stormwater Runoff in Sponge Reconstructed Community Based on SWMM

A multi-level regulation system of stormwater runoff in a sponge reconstruction demonstration project of a residential community of Tongzhou, Beijing was established by SWMM software. The model parameters were calibrated and verified by measured rainfall data. The influence of LID facilities and pipeline parameters on stormwater regulation capability before and after sponge reconstruction at different scenarios was analyzed. After the firstª²level regulation, annual runoff control rate could reach 41.51%-57.40%, and the reduction rate of pollutants was more than 25%. The secondary level regulation of storm pipeline size was the most effective. No ponding took place in the area during the rainfall with 10-year return period when the bottom width or the maximum depth of drainage ditch increased by 60%. The third level regulation of reservoir volume could realize no ponding in the community during the rainfall with 3- year return period, and the utilization rate of rainwater resource could reach 3.93%.