What is Stormwater & Where Does it Go?
Stormwater is rain and melted snow. When not absorbed into the ground it runs off properties:
- along streets
- down storm drains
- through a complex network of pipes that carry it into:
- local waterways or, in some cases
- wastewater treatment facilities.
The combination of an increase in extreme storms and hard surfaces covering the city is resulting in more water making its way into the stormwater system. Too much water in the City’s stormwater system can overwhelm it leading to:
- flooded basements
- poor water quality in local waterways, including Lake Ontario.
There are two types of sewer system designs in the city.
- Separated sewer systems, found in the newer parts of the city, in which:
- sanitary sewers carry sewage to wastewater treatment plants
- storm sewers carry stormwater (rain and melted snow) directly to nearby waterways
- Combined sewer systems, prevalent in older parts of the city, in which:
- one pipe is designed to take both sewage and stormwater directly to wastewater treatment