Storm water billing

Storm water billing is not based on a water meter. It attempts to compensate for the amount of rain water that is not absorbed by the soil because there is some surface erected over the soil on privately-owned property – building, footpath, garage – that causes a water run-off into the public drainage system. This is usually known as the “impervious area”. Since these areas vary in size, billing systems usually apply stepped rates – if the area is up to A then the rate is Y, if it is between A and B, the rate is X and so on.