Stormwater Management Ponds

Ponds that help control the flow of surface water from a rain storm or melting snow.

In developed areas, there are a lot of hard surfaces, such as pavement and buildings. Runoff water from rainfall and melted snow can not easily absorb into the ground through these hard surfaces. 

Runoff will build up and travel quickly to the storm sewers, creeks and Lake Ontario. As the runoff gathers, the risk of creek erosion and flooding increases. Runoff water can also pick up contaminants from the hard surfaces.

Stormwater management ponds (SWMPs) help to control the quantity and quality of water runoff that enters storm sewers, creeks and Lake Ontario. SWMPs help prevent flooding, creek erosion and pollution. 

The town currently operates and maintains 52 SWMPs and there are 15 additional ponds awaiting assumption by the town.

Our stormwater management system directs water into SWMPs using catch basins, storm sewers and overland flow routes. 

All SWMPs have at least one inlet that receives runoff water from the stormwater network. The runoff water is stored in the SWMPs and released at a slower, controlled rate. This reduces the potential for creek erosion and flooding. 

SWMPs also improve water quality. Debris and contaminants in the runoff water settle to the bottom of the SWMPs as sediment before the runoff water is released. The areas around the SWMPs are landscaped with dense natural vegetation to help filter sediment.

Visit our YouTube channel to learn more about how these ponds work.

We complete visual inspections of all SWMPs each year. These inspections identify routine and non-routine maintenance needs. 

Routine maintenance includes:

  • Removal of debris in and around the SWMPs
  • Removal of invasive plants
  • Maintenance of structures (gates, locks, valves, etc.)
  • Maintenance of surrounding plants

Non-routine maintenance includes:

  • Bank stabilization
  • Structural repairs
  • Draining the SWMPs to remove sediment 

SWMPs will not function properly if they are full of sediment. When the sediment reaches a certain level, the SWMPs must be drained and the sediment removed.  

Depending on their size and location, SWMPs normally require sediment removal approximately every 10 to 25 years. 


A few things that you can do to help our SWMPs and improve water quality include:

  • Dispose of trash properly to avoid litter build up in and around the SWMPs
  • Dispose of your grass clippings or leaves properly to avoid build up in and around the SWMPs
  • Minimize the use of fertilizer
  • Avoid disturbing the plants around the SWMPs
  • Avoid draining swimming pools or dumping toxic substances (oil, anti freeze) into the SWMPs or into storm sewers
  • Report evidence of beaver activity (damming) or other animal activity by calling 905-845-6601
  • Do not plant any trees in a park area that contains the SWMPs without approval from the town
  • Obey all signs posted around the SWMPs

Benefit of a litter clean up!

  • Reduce the potential for clogging outlets, trash racks, and other parts of the SWMPs
  • Prevent damage to plants and vegetation
  • Reduce potential mosquito breeding habitats
  • Reduce conditions for surface algae
  • A nice looking SWMPs


For your health and safety recreational activities are prohibited, including, but not limited to:

  • Swimming
  • Skating
  • Wading
  • Boating
  • Fishing
  • Sledding

Due to water constantly moving in and out of the SWMPs, water levels can change quickly. In addition, ice that forms in the winter is unpredictable because there may be salt in the water.

Safety/warning signs have been placed at each of the ponds to inform you of prohibited activities. If you visit our SWMPs with younger family members or friends, please review the warnings and make sure everybody understands.

Make the safe choice and stay out of the SWMPs

For more on stormwater management pond safety, here is a message from our Fire Chief.

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