Maintenance of Stormwater Management Facilities

Stormwater management facilities, or stormwater ponds, serve to control and treat the runoff from urban areas before it discharges into our watercourses such as rivers and streams. There are over 140 stormwater ponds in Markham with over 110 owned and maintained by the City. Several new facilities are added each year.

The City inspects, maintains and where appropriate retrofits assumed facilities to maintain or enhance their function. Retrofits to older facilities can include:

  • enhancing the runoff detention capability to reduce erosion stresses in downstream watercourses,
  • adding “cooling trenches” to limit temperature impacts on sensitive aquatic species, or
  • adding earth berms to enhance water quality treatment and facilitate future sediment removal activities.

While ponds can appear as attractive, natural features and are often surrounded by trails and parks, the public is encouraged to exercise caution around facilities due to fluctuating water levels and hazards associated with deep pools and fast moving water at inlets and outlets.

Swan Lake is an example of a stormwater management facility that is receiving ongoing monitoring to ensure healthy water quality is maintained.