Vehicular traffic contributes significantly to pollutant buildup in urban carparks and the resulting storm wash-off needs to be treated before it is discharged into receiving waterways. First flush samples from 20 storm events were analyzed to investigate TSS and heavy metal discharge from three urban carparks with different traffic conditions. TSS and total Zn loads in an industrial carpark were found to be higher than in a university and a hospital carpark; however, dissolved metals concentrations were higher for the latter two sites. Results indicate that the design of stormwater filter devices needs to suit carpark characteristics and that a “one size fits all” approach is not adequate.