WWFMP - 25-year plan
Controlling the debris and pollution that enters our stormwater system is a daily operational commitment. Street sweeping, catchbasin cleaning and standard maintenance procedures are all part of the job. But our 25-Year Plan to help solve water pollution goes beyond that. Take a look at what we’re planning to do over the next 25 years to handle stormwater pollution due to wet weather flow.
Public education
Getting you involved is the real key to the success of dealing with stormwater pollution. That's why raising individual awareness about the WWFMP, its projects and programs is the thrust behind our public education and outreach campaign.
Our campaigns include:
- Stormwater mass media campaign: “Not Grate for the Lake,” “Where Does the Oil End Up” and “Please Walk on the Grass” are just some of our campaigns to raise public awareness about stormwater pollution and encourage public involvement.
- Yellow Fish Road program: This inter-active program sponsored by the Toronto Regional Conservation Authority (TRCA), provided school children of all ages a chance to make a difference by stencilling yellow fish beside storm drains. The idea was to teach them that whatever goes down the drain ends up in a lake or river and that it’s illegal to dump down drains. Read more about the TRCA's Watershed on Wheels in-school programs.
To build on these programs, the WWFMP goes a step further by:
- Establishing a network of community and business partners to work together to prevent stormwater pollution
- Promoting stormwater pollution prevention solutions
- Developing social marketing programs that encourage Torontonians to adopt environmentally sound behaviour
- Celebrating and rewarding our partners who help promote and contribute to pollution solutions
Source controls
Source control measures are the first step in the hierarchical approach to managing wet weather flows by dealing with stormwater on site where it falls. These measures are carried out through programs such as:
- Mandatory Downspout Disconnection Program: This program reduces basement flooding, decreases lake and river pollution, and captures water from disconnected downspouts and then reuses it for watering gardens and grass.
- Green Roof Incentive Pilot Program: The overall goal of this program is to encourage green roof construction in the City. In addition, the program will benefit stormwater management by the reduction in stormwater flows.
- Rainwater Harvesting Demonstration Project: Rainwater harvesting not only manages the path taken by storm runoff to the lake but also diverts it to on-site non-potable uses such as irrigation and toilet flushing, thereby reducing potable water use, saving energy, operating costs and meeting WWFMP goals. Demo project will be taking place at the Automotive Building at Exhibition Place.
- Tree Planting: Planting trees can have multiple benefits in urban areas, including reducing the volume of stormwater runoff. While planting trees can help capture an initial portion of stormwater runoff, it can also increase evapotransporation (water expelled to the atmosphere) and infiltration.
"Search and destroy" cross connections
A cross connection is created when a household sanitary plumbing fixture is mistakenly connected to a storm drain, sending waste directly to a watercourse. Cross connections are responsible for polluting our rivers with raw sewage and contributing to beach closings in the summer due to elevated E.coli (bacteria) levels. Our mission: to locate these cross-connections and fix them.
Basement flooding protection
Protecting homes from basement flooding is one of the City’s first wet weather flow or stormwater pollution prevention projects. Over the next five years, the City is tackling those clusters or areas particularly vulnerable to basement flooding. Some of the ways we’re dealing with it are by:
- replacing sewers where possible
- introducing isolation valves; these valves automatically close when the sewer backs up, stopping water from entering the basement
- reimbursing for the disconnection of weeping tiles and downspouts which contribute to basement flooding
Conveyance controls
Controlling the stormwater as it travels along the drainage system is what conveyance controls methods are all about.
Two major types of conveyance controls are the exfiltration and the filtration systems. Simply put, they refer to having “leaky” pipes that allow the stormwater to leak through and, where possible, seep into the ground. If the soil can’t absorb the water then porous material, such as sand or gravel, is put around the pipes to help filter the stormwater. What isn’t captured by the soil or sand re-enters the stormsewer pipes where we try to control it at end-of-the pipe.
Other conveyance controls include ditches (or swales) and sewer separation -- one of the methods we’re using to handle combined sewer overflows and basement flooding.
The goal is to protect the existing ditch network or put in “leaky” storm sewers to about 25 per cent of the system.
Beach water quality improvements
Toronto’s beaches are some of our greatest treasures. But a few times during the summer, stormwater pollution can take away the pleasure we get from swimming in them during those hot, humid days.
That’s why we have to capture the stormwater before it enters the beach and treat it. And we plan to do this with end-of-pipe solutions such as tanks, tunnels and a flow balancing system. Sounds like a book title…but it’s actually an effective way to improve beach water quality. Here’s how:
- Tanks and tunnels capture and hold combined sewer overflows and stormwaters which then are treated before returning to the lake.
- The captured flow in tunnels and tanks use ultraviolet lights to kill bacteria in the water before releasing it slowly back into the lake.
Flow balancing captures stormwater runoff and filtrates treat it through the use of ponds and wetlands. One example of a flow balancing system is Dunker’s Flow at the Scarborough Bluffs.
Using tanks and tunnels for storing sewer discharge for subsequent treatment is an effective concept that we’re already using in this city. In fact, our eastern beaches have tanks and our western beaches have a storage tunnel but more is needed to protect the environment.
Areas scheduled for work in the early stage of the plan include the Eastern Beaches and the Etobicoke, Toronto (Ellis Ave.) and Scarborough waterfronts.
Stream and aquatic habitat restoration
Stream erosion in various waterways is hurting the stream valley system and affecting aquatic life. To correct this, we are:
- restoring degraded sections of streams
- revegetating various streambanks
- removing fish barriers to allow fish species to pass through
- reforesting and creating wetland
- restoring the Humber River Marsh
This work will take 15 years to complete.
End-of-pipe facilities
If we’re unable to remove enough stormwater when the water enters the system or transports across it, then it will be tackled at end-of-pipe. As the name suggests, this is where the stormwater pollution journey ends before it enters the lake or other water bodies.
Two types of end-of-pipe facilities exist: above ground, which involves stormwater ponds and constructed wetlands, and below ground facilities such as storage tanks and tunnels.
We’ve planned more than 200 end-of-pipe projects, with the bulk of them being above ground. Above ground is preferred because facilities are easier to access, maintain and are cost-effective to build. We do, however, need a lot of land to build wetlands and ponds.
Where land is at a premium, we go underground and build storage facilities or tunnels. Not as easy to get to but definitely very effective in dealing with stormwater and combined sewer overflows (CSO). The plan calls for the building of:
- 175 ponds/wetlands
- 175 subsurface stormwater management facilities
- 44 CSO storage and treatment facilities
Monitoring plan effectiveness
How effective is our plan? Is it meeting our expectations? Are the projects meeting their targets?
Throughout the life of the plan, we’ll be looking at different measurements (depending on the projects) to answer these and other questions to know how well our plan is working.
For instance, we’ll be monitoring ponds, wetlands and shorelines against specific baselines (or references points) to see if they’re performing as expected. Bottom line: we want to know if our projects are making the right kind of difference. Of course, all plans are ‘living’ documents that evolve. That’s why monitoring also identifies projects which might need modifying throughout the 25-year period.