Stormwater Management Ponds

The Town of Whitby currently owns and maintains 44 stormwater management ponds (SWM) with more than 10 additional ponds pending assumption throughout the municipality. As owners of SWM facilities it is the Town's responsibility to clean and maintain them in proper working condition.

What are stormwater management ponds?

Stormwater management ponds are containment facilities designed to collect runoff from the local storm sewer system. Water enters the storm sewer system through the following:

rainfall
snowmelt
activities such as washing cars or watering lawns

Stormwater management ponds are built to temporarily hold this water, provide treatment to remove the pollutants, and then slowly release the water back into the natural waterway to prevent downstream erosion and flooding.

Public access is prohibited

Public access to stormwater management ponds is prohibited due to unsafe site conditions such as:

Murky water
Sudden drop offs
Subsurface currents
Potential for entanglement with vegetation, sewer debris or containment booms

These hazards are created when the water levels in stormwater management ponds experience dramatic and rapid changes during and following periods of rain and snow melt.

Safety tips

Here are some tips for safety around stormwater management ponds:

Exercise caution at all times around frozen ponds or bodies of water as the fluctuating temperatures and use of road salts can create thin or unstable ice and potentially hazardous conditions
Stay away from the pond's side slope, vegetated barriers and outfall areas
Be aware that water levels can rise rapidly, so never wade or swim in a stormwater management pond

Stormwater management ponds are not intended for recreational use. We don't monitor the water level or ice thickness and will vary. Town assumes no responsibly for unintended use.

Don't dump garbage or other household waste (including used medical products, fertilizers, soap scum, paint, oil, etc.) into storm sewers, creeks or stormwater management ponds because these pollutants represent a community safety hazard and compromise the environment.

To learn more about stormwater management ponds and proper clean-out, visit the Ministry of Natural Resources and Forestry.

Wildlife protection for stormwater management ponds

The Town makes a conscious effort to protect the fish and wildlife that have inhabited stormwater management ponds. If we need to complete work on or near stormwater management ponds, we take the following safety precautions:

Fish and amphibian rescue is completed prior to works and is an accepted practice by the Ministry of Natural Resources and Forestry
Birds and mammals that are often found around the ponds are mobile and will leave the work areas during the maintenance however, will return to the habitat when it is safe to do so
The time frame chosen for the work considers bird migration and nesting in order to minimize impacts to the birds during sensitive times

Study updates for stormwater management ponds

Review recent studies on stormwater management.

Storm sewer outfalls study

There are more than 230 storm sewer outfalls along the three major creeks to discharge storm water runoff collected by the storm sewers. The Town conducted a stormwater outfall study in 2001 and the study revealed that the majority of the outfalls constructed before the stormwater quality control concept didn't have any quality control mechanism.

The outcome of the 2001 study was the identification of SWM upgrade opportunities, including the location of specific quality and erosion enhancement features. Based on the outcome of the assessment, a total of 14 water quality and erosion control enhancement projects were identified and prioritized based on environmental and cost factors. Based on the study recommendation, a pond construction program was developed and included in the capital budget. Six new stormwater management facilities were constructed under the pond program including four wet ponds/wetland facilities and two large oil and grit separators.

The 2001 study report was revised again in 2019 study and under the study many of the outfalls were revisited and previous recommendations were reevaluated based on:

Contributing drainage area
Contributing impervious area
SWM water quality and erosion control
Impacts to the physical environment and sensitive channel reaches
Construction cost
Private property constraints

Twelve stormwater enhancement projects (ponds, plunge pools and oil and grit separators) were proposed under the study update and prioritized. The current Town Pond construction program was revised based on this priority list and included in the next 10 to 20 years capital budget forecast for construction.

Stormwater management ponds needs study

The Stormwater Management Ponds Needs Study was first completed in 2011 to assess the sediment accumulation in Town owned Stormwater Management Ponds. The study included 31 stormwater management ponds to identify short term and long term sediment removal requirements.

Based on the study recommendation, a pond cleanout program was developed. Since then, 19 facilities have been cleaned, 6 facilities have not yet been cleaned and the remaining 6 facilities do not need cleaning as they are dry ponds.

Since the first study was completed, the Town has added many more ponds through subdivision projects. Eleven ponds were studied again under the 2019 study including 6 ponds, which were reevaluated. Ponds were evaluated based on sediment accumulation and a priority list was developed. Based on this list, current pond cleaning program was revised in included in the capital budget forecast and will be executed under capital works or through any other funding opportunities.