Stormwater

When rain falls in natural environments, much of it is infiltrated through the soil and slowly discharged into local streams.

When rain falls in urban environments, much of it is not infiltrated. This is because roofs, roads, sidewalks and other impervious surfaces do not allow rain to infiltrate into the soil.

• Instead, stormwater runs off these surfaces, picks up pollutants, and is discharged rapidly to local streams.
• Also, urban stormwater runoff results in poor groundwater recharge.

Poor stormwater management leads to erosion, poor water quality, pollution and property damage caused by flooding. In order to mitigate the undesirable impacts of urbanization stormwater management practices are implemented to preserve the natural hydrologic cycle, and protect and enhance stormwater quality before it outlets to the natural environment.

Caledon is uniquely positioned in the headwaters of the Credit, Humber and Etobicoke Rivers with much of the landscape and its thriving environment influenced by the ecologically and hydrologically significant natural and scenic features of the Niagara Escarpment and Oak Ridges Moraine.

Together with the Oak Ridges Moraine Conservation Plan, the Niagara Escarpment Plan and Watershed Plans, the Greenbelt Plan provides direction on the protection of the key natural features that comprise the Caledon landscape. With this unique geographical position, the Town works to manage the impacts of growth in line with each plan and is committed to sustaining the health of the natural landscape by working closely with Conservation Authorities.

The Town’s stormwater management infrastructure helps to manage runoff and minimize the risk of flooding. As the impacts of climate change continue to be felt, Caledon is expecting increased frequency and severity of rainstorms and droughts.

Changing precipitation patterns and Caledon’s continued growth require that the Town apply a treatment train approach to stormwater management. The treatment train approach involves managing rainfall at the lot level, along the conveyance path, and at the end-of-pipe to meet multiple objectives for quantity, quality and erosion control.

The use of a treatment train approach to stormwater management provides the redundancy necessary to building a sustainable Caledon. In addition to managing stormwater through a treatment train approach in new developments, the Town will continue to improve the operation and maintenance of stormwater throughout the existing urban network by including innovating practices in our older areas as opportunities arise.