Evaluation of low impact development and best management practices on peak flow reduction using SWMM

Rapid urbanisation has caused an increased in peak discharge that conventional drainage systems cannot adequately handle. Low Impact Development (LID) practices are becoming a new approach in helping to better mimic the pre-development discharges. This study aims to evaluate the effectiveness of LID and Best Management Practices (BMP) under different rainfall conditions. Vegetative swale and detention pond were selected to represent LID and BMP. Simulations of four main scenarios namely, base case, LID, BMP, and combined LID-BMP were performed using Stormwater Management Model (SWMM). Results show that among the scenarios simulated, the combined LID-BMP is most effective with average peak flow reduction of 54%. This is followed by BMP that achieved 37% in average peak flow reduction as compared to 27% peak flow reduction by LID. The findings indicate the need for integrated strategy when dealing with stormwater management measures.