Charges are calculated using property size (A), development intensity (I), and a runoff coefficient (R), based on land zoning and a city-wide monthly rate.
The charges are calculated as follows:
A x I x R x Rate = Stormwater utility charge
A: The area of the property in square metres (m2), and the proportion of the building lot area attributable to each unit for multiple units sharing a single building of property.
I: The measure of the portion of lot being used for its intended development. The development intensity factor of 1.0, except for properties where owners demonstrate that they contribute significantly less stormwater runoff per property area to the City's land drainage system during rainfalls than other similarly-zoned properties.
R: Runoff coefficient—the permeability of your lot's surface (i.e. grass versus concrete), based on land zoning.
- The run-off coefficient for a single detached residential house is typically 0.50. However, depending on your property's land zoning classification, the run-off coefficient can range from 0.20 to 0.95.
Rate: The monthly charge of $0.046490 per square metres (m2).