Application of a catchment water quality model for an East-Australian catchment

This paper presents the calibration of a catchment water quality model developed for the continuous simulation of stormwater pollutants from a catchment to the catchment outlet. Calibration of the model was performed using the rainfall and water quality data collected for 'Saltwater Creek Catchment' in Gold Coast, Australia. Runoff estimations from the hydrologic model were compared with calculated discharges through widely used Australian runoff models, WBNM and DRAINS. Sensitivity analysis of the model parameters showed that maximum build-up rate, build-up rate coefficient and wash-off coefficients are sensitive parameters of the model. Based on measured water quality data, different parameters of the model were calibrated for the above-mentioned catchment. Calibration of the model was demonstrated for the water quality pollutants suspended solids (SS), total nitrogen (TN) and total phosphorus (TP).