What is a Stormwater Management Pond?
A stormwater management pond is an engineered structure constructed to gather rainfall and surface water runoff. The pond temporarily stores water and then releases it at a controlled rate. A single pond can provide erosion and flooding control while enhancing water quality.
Through a combination of landscape and structural features, stormwater management ponds allow sediment and contaminants to settle out of runoff before it is released into a natural watercourse. Stormwater ponds also hold back water in order to release it at a controlled rate during large storms. Controlling the flow of stormwater protects downstream lands from erosion and flooding.
In addition, stormwater ponds are constructed to be an attractive feature with an environmental benefit. Stormwater management facilities are designed to be surrounded by natural vegetation and to provide habitat for birds and animals.
How can you help?
- Do not pour anything down the catchbasin that you would not want in a stream or river
- Properly dispose of pet and yard waste
- Minimize the use of fertilizers and pesticides on your lawn or garden
- Recycle and safely dispose of hazardous waste such as used oil, paint, paint thinners, and batteries
- Use eco-friendly salt alternatives for melting ice and snow
- Do not release unwanted household fish, game fish or aquarium pets into the pond (contact pet store where purchased or The Ministry of Natural Resources for proper disposal)
- Drain pools and hot tubs only after they are free of chemicals and salt
- Use a commercial car wash or use eco-friendly car wash soap
- Ensure your vehicle is not leaking fluids
- Allow for a natural un-mown buffer around ponds while respecting municipal property lines
- Plant native species of shrubs, wildflowers, and trees
Protect Natural Buffers
Stormwater ponds are designed to mimic a natural system; therefore, it is important to allow a natural buffer to grow around the perimeter of the pond. The natural buffer is made up of native plants and grasses and should not be mown or trimmed. It is important to note that the property lines for homes near stormwater ponds do not extend to the water's edge. These buffer areas should not be mown or altered.
Reduce or Eliminate the use of Fertilizers and Pesticides
The use of pesticides or fertilizers in grassed lawns around stormwater ponds should be limited or eliminated completely. These chemicals are easily carried away by runoff into the stormwater pond which can cause algae blooms and negative impacts to the downstream natural watercourse. Where possible, use organic alternatives to chemicals and plant native species that require low maintenance and no pesticides.
Planting native species of trees, shrubs, grasses and flowers has numerous benefits. These species can dramatically reduce the amount of water used for irrigation, chemicals used for pest control, and fertilizers used for growth. Information on native landscaping species can be obtained from the Upper Thames River Conservation Authority.
Managing Yard Waste
Dumped yard waste in natural areas or around stormwater ponds can have an adverse affect on the health of the natural system. Dumped materials smother natural vegetation, may contain harmful chemicals, and non-native plant seeds. The best solution is to compost leaves, grass clippings, and weeds on your own property. The City of London has yard waste collection days for brush and leaves throughout the year. To learn more about waste collection days, please refer to the most recent version of the City of London’s Residential Recycling and Garbage Collection Calendar.
Did you know?
Over time, sediment will accumulate in the pond reducing the pond's ability to improve water quality. As part of the City of London's maintenance program, a pond clean-out will occur to restore the water quality function. During the pond clean-out, the water level in the pond will be lowered to safely remove the sediment and some vegetation may need to be removed. An ecologist will safely manage any wildlife that may be impacted in accordance with the City's Human Wildlife Policy. The sediment will be tested for contaminants and disposed of safely at a waste facility or dried out and reused depending on test results. During a pond clean-out, additional repairs may be completed. It usually takes one or two seasons for the pond to look natural again.
Mosquitoes and Stormwater Ponds
Stormwater management ponds are designed in such a way to prevent mosquito breeding. Mosquitoes need shallow water depths and standing water; where as stormwater ponds are deep and water is moving, (water from the ponds is typically draining below the surface which impedes mosquotoes from laying their eggs)
Culex pippiens and restuans are the most common carriers of West Nile Virus and prefer to lay their eggs in artificial containers with standing water (like old tires, buckets, birdbaths, etc).
If you have any concerns or would like to report mosquitoes please contact the Middlesex Health Unit.