What is stormwater?

In a natural environment, rain and melted snow fall onto soft surfaces such a grass and infiltrate into the ground. In urbanized areas, rain and melted snow fall onto hard surfaces like roads, driveways and sidewalks and continue to travel without infiltrating. This can cause flooding.

As the rain and melted snow flows across these hard surfaces it collects oil, dirt and pollutants. The rainwater mixed with pollutants then flows into our storm sewers, stormwater management ponds, rivers and natural waterways. The Ministry of the Environment, Conservation and Parks (MECP) defines this mixture of rainwater and pollutants as municipal sewage.

What is a stormwater management pond?

Stormwater management pond cycle

A stormwater management pond is man-made infrastructure built to collect and treat rainfall and surface water runoff, as required by MECP legislation. The ponds are usually found in neighbourhoods, where stormwater can easily be collected and treated.

During rainfall, stormwater flows into the pond and fills the basin of the pond. As the pond fills, dirt, sediment and pollutants settle down to the bottom. When the pond fills to its capacity, the water spills out at a controlled rate to reduce flooding and erosion to local waterways. The pollutants and sediment are left behind in the pond. Aquatic plants in the pond help with treating pollutants and plants around the edges of the pond help to stabilize banks and shade the water.

Staying safe around the pond

As these ponds mature, they are also pleasant to look at and walk near. Practice safety when around a stormwater pond as water levels can change quickly during storm events.


  • Keep catch basins clear of debris
  • Enjoy passive recreation around the ponds (walking, bird watching)
  • Report illegal dumping to the Town by calling 905-878-7252


  • Put anything, including garbage and pollutants, down catch basins or in a stormwater management ponds
  • Engage in recreational activities (skating, swimming, fishing, boating, etc.) in the ponds


 How does Milton manage stormwater?
We manage stormwater with a robust infrastructure system. Stormwater flows over hard surfaces and is captured in catch basins within the Town’s roads. These catch basins are connected to storm sewers that lead to stormwater management ponds.
 How does Milton manage stormwater management ponds?

The Town owns and operates stormwater management ponds after assumption of a subdivision. We inspect the ponds annually and conduct an in-depth inspection, including the measurement of sediment every five years. After approximately 15 to 20 years, the Town removes sediment from the pond.

To remove sediment, we need to pump water out of the pond, relocate wildlife and remove sediment with the use of heavy machinery. This process is invasive, but is also necessary to ensure that there is space available in the basin to continue collecting stormwater and sediment, in order to reduce flooding and protect local waterways.