WWFMP - Frequently asked questions
What is wet weather flow?
Wet weather flow -- also known as stormwater pollution -- is runoff that’s generated when it rains or snow. In a natural setting where there’s a lot of grass or vegetation it’s not usually a problem because the rain filters into the ground. But we live in a modern city where there’s a lot of concrete, asphalt, brick, and this changes the way water moves and what it picks up along the way to the sewer.
That means that, in our city, a lot of stormwater runs off roofs, roads and parking lots. It trickles down drain pipes and empties into stormwater grates. Once it enters the grate (having collected dirt, oil, grease and a lot of other debris along the way), it then travels through our extensive storm sewer system - 4,500 km in all - to some 2,600 outfalls or outlet pipes. From there it enters our rivers, streams and Lake Ontario.
Why is stormwater pollution a problem?
Stormwater pollution affects our environment, and here’s why:
- It picks up oil, grease, metals pesticides and other pollutants and deposits them in streams and along the waterfront.
- It contributes to poor water clarity, high concentrations of bacteria and elevated concentrations of metal and organic contaminants and the piling up of trash.
- A lot of diluted sewage is discharged into our rivers and the waterfront because of combined sewer overflows. Combined sewers have single pipes which carry both sewage and stormwater.
- Runoff generated when it rains also leads to surface flooding, erosion of streambanks, destruction of fish habitat and basement flooding, to name a few.
How much will Toronto's Wet Weather Flow Master Plan (WWFMP) cost?
The 25-year implementation plan addresses a whole spectrum of goals including, but not exclusive to:
- protecting our environment
- basement flooding protection
- keeping our beaches safe to swim in
- promoting health and safety
- meeting legislative requirements
The capital cost to meet these goals, supported by a multitude of projects, is estimated at $42 million annually, over the next 25 years. Operational costs for these projects once in place are approximately $16 million per year.
How can I help eliminate stormwater pollution?
Individual participation plays a big role in handling stormwater pollution. Here's how you can help:
- disconnect your home’s eavestrough downspouts from the sewer. See downspout disconnection
- don't use chemical fertilizers and pesticides. It's against the law.
- leave mulched grass clippings on your lawn to help absorb rain.
- take your car to a commercial car wash for cleaning to reduce the amount of toxins entering the storm sewers.
- don’t dump toxic substances into the sewer. Take them to Household Hazardous Waste Depots.
- stoop and scoop animal waste.
- put in porous pavement in your driveway or patio..
- increase the amount of green space around your home, by planting native plants and trees.
- use the water that falls on your property. Don’t let it go down the drain
Why will the Water Pollution Solution take so long to implement?
No matter how you look at it, putting in place water pollution solutions is a long-term commitment. There are several reasons for this:
- Toronto is a large urban centre. That means we have to balance the social, financial and environmental issues that a big city likes ours faces every day.
- We’re connected to other neighbouring municipalities by watersheds. What we do affects them and how they manage their water issues affects us. This requires monitoring and reviewing the process every step of the way.
- The environmental impact on our neighbourhoods, beaches and city, in general, also demands that each project undergo an environmental assessment. Environmental assessments – which include hearing from neighbourhood committees, officials, etc., - can take up to three years before construction begins on a project.
- Residential participation is another key factor. Many of our solutions require involvement by everyone…especially our citizens. Whether it’s disconnecting downspouts, eliminating the use of pesticides, toxins or putting porous pavements in place, we can’t do it alone. One way we are encouraging participation is through education and awareness. Changing the way we think or do things is not something that happens over night.