About Stormwater Management Ponds
After rain or snowfall, the water left behind on roads, sidewalks, grass and pathways is called “stormwater.” This is ordinarily absorbed into the ground by plants and soil. However, pavement and other hard surfaces — such as driveways, sidewalks and roofs (especially in urban areas) — can interfere with this absorption. This can lead to water pooling or even flooding.
To help take care of this, stormwater management ponds typically exist in urban developments. They are human-made areas created to gather and retain rainfall and surface water runoff. These ponds are usually found in neighbourhoods where stormwater can easily be collected.
Stormwater management ponds can be either wet or dry and they are designed to maintain a permanent body of water within the pond area.
A dry pond is designed to remain dry until a rain event occurs which may temporarily retain stormwater within the pond area. A wet pond holds water all the time and is designed to collect and store runoff from rain and melted snow. These wet ponds collect sediment so only clean water is released back into rivers and creeks.
How Stormwater Ponds Work
Stormwater ponds have at least one inlet that allows water to flow from the storm sewer system into the pond. Once the stormwater drains into the stormwater pond, any of the sand, dirt and other sediments that pollutants attach themselves to settle to the bottom of the pond. The pond's outlet releases water from the pond into a nearby river or lake system at a controlled rate. This process helps make the water cleaner when it leaves the pond and back into lakes and rivers. Without stormwater ponds, large amounts of water would enter a stream all at once, causing flooding and eroding soil from the stream banks.
Benefits of Stormwater Ponds
- Reduces flooding
- Protects the natural environment from contaminants and erosion
- Protects rivers and lakes by trapping pollutants such as oil, pesticides, bacteria and trash
- Establishes a human-made habitat for wildlife
- Encourages a naturalized space for walking and bird watching
Staying safe in the winter
Stormwater management ponds may look safe to walk and skate on, but they are extremely dangerous due to water constantly flowing in and out of the pond underneath. These ever-changing water levels make the thickness of the ice highly unpredictable. This is a serious safety hazard and one of many reasons to stay off the ice.
Staying safe in the summer
Swimming, boating and fishing are not safe in stormwater management ponds due to the constant flow of water in and out of the pond, multiple pollutants and unpredictable water levels. The bottom of stormwater management ponds is very soft and anyone, including pets, who enter may quickly become stuck.
Prohibited Activities
- Skating, Swimming, Fishing, Planting
- Planting gardens or cutting grass on pond property
- Storing yard materials on pond property
- Installing gates to access pond property from fenced yards
- Disposing of grass clippings, yard waste or garbage on pond property or into the pond
- Disturbing plants and vegetation around the pond
- Disposing of pet fish in the pond
- Disposing of swimming pool water and chemicals on pond property or in the pond
Maintenance of Stormwater Ponds
Each of these ponds need to be properly maintained to control the flow of water. Year-round, routine maintenance includes removal of debris in and around the pond, removal of invasive vegetation; maintenance of structures such as inlets and outlets, and maintenance of surrounding vegetation and plants.
Reporting an issue
Notice a stormwater pond that requires attention? Report issues, including any odours, beaver activity (damming) or high-water levels at here!
Individuals found dumping their household garbage are subject to a maximum fine of $5,000 per offence. If you witness illegal dumping or littering at a stormwater pond, please report it to Town of Gravenhurst at 705.687.3412 or www.gravenhurst.ca
