Monitoring & Modeling Stormwater Quality for a Catchment in Malaysia

Urbanization has been found to impact stormwater runoff quantity and quality. A study catchment with mixed land use, residential and industrial were investigated and the water quality discharged from the catchment were sampled and tested. The results were analyzed to compare against stowmwater quality benchmark limits, typical stormwater characteristics, effects of rainfall on dry event water quality, first flush phenomenon, comparison of wet and dry event water quality based on land characterize/land use as relative sources. Storm duration is a substantial parameter to characterize the rainfall depth and intensity thus affect the resulting runoff peak and water quality. A typical rainfall duration is computed to stimulate rainfall-runoff using EPA Storm Water Management Model (SWMM) of the subcatchments within the watershed. Parameters used to develop the model of the study catchment are discussed. The nature of the pollutant to the projected rainfall within the model watershed is evaluated.