Optimization of the design of an urban runoff treatment system using stormwater management model (SWMM)

This study presents an application of stormwater management model in predicting the optimal physical characteristics and rainfall design criteria of an established low impact development (LID) treating urban stormwater runoff. The optimization of this LID was performed for the purpose of enhancing the treatment performance and serve as future guidelines in designing treatment systems. The values of different calibration parameters used in the model were obtained from the 10 monitored storm events conducted from July 2010 to July 2013. Based on the findings, the runoff volume reduction of the system was found out to be directly proportional with storage volume/surface area (SV/SA) ratio. However, it was also dependent on the amount of rainfall during a storm event. For the total suspended solids load reduction of the system, it has no significant relationship with the rainfall but found to be directly proportional with SV/SA ratio as well. Lastly, the physical dimensions of the system were also analyzed with respect to the SA/SV ratio.