Understanding the Interrelationships Between Stormwater Quality and Rainfall and Runoff Factors in Residential Catchments

This paper discusses the outcomes of a research project which involved in-depth investigation of stormwater quality by analysing rainfall-runoff and water quality data from four urban residential catchments. The outcomes of the investigations confirmed that the pollutant export characteristics from these catchments are strongly correlates with the rainfall intensity rather than other rainfall-runoff parameter. Further, the overall pollutant export from the catchment is mostly dependent on lesser number of high intensity storm events. These findings suggested that the rainfall intensity would be the most suitable rainfall-runoff parameter for pollutant export equations in stormwater quality models. Furthermore, the variation of stormwater quality with range of rainfall-runoff parameters emphasis the necessity of long term calibration of models.