Experimental results are described to evaluate the diffuse pollution profile according to land use in the catchments and street sweeping as a best management practice (BMP). We studied the variation of pollutant concentrations in outfalls discharging runoff from residential, commercial and high-traffic areas and in street sweeping. Pollution profiles varied with the land use in the catchments and seasons along with other factors such as rainfall intensity, construction works and street maintenance. Microbial indicator organisms were relatively high in all three outfalls. Heavy metal concentrations were low with lead (Pb) as the predominant heavy metal. The organic and solid contents were low but non-degradable and persistent. Relatively high quantities of pollutants were found in street sweeps in all catchments suggesting street sweeping as an effective measure to control diffuse pollution. Regular and frequent sweeping is important as a BMP.