City of Toronto Crews Prepare for Wet Weather Conditions

Posted on May 4, 2017

City of Toronto crews are preparing for rainfall that is expected to start later today and add significantly to Toronto’s existing high water levels. The City and agencies including the Toronto and Region Conservation Authority (TRAC) are working with residents to prevent or minimize flooding and related problems.

A low-pressure system reportedly moving into southern Ontario this afternoon is predicted to bring heavy rainfall – from 40 to 70 millimetres between today and Saturday, according to Environment Canada. Toronto has already received more than 100 millimetres of rain since early April, which has resulted in rising water levels in Lake Ontario and some flooding in low-lying areas and beaches along the city’s waterfront.

The high water levels in Lake Ontario this spring are also seen in rivers and streams, which are moving quickly and at high levels. Residents are advised to stay clear of rivers and streams throughout the city and to take precautions to protect their properties. During heavy rain storms, residents are advised to avoid travel and are asked to check in on elderly neighbours or other people who may need assistance.

The ground is already wet and unable to absorb as much rainfall as would under normal spring conditions. During a rain storm much of the rain falling in the city will flow on top of the ground and drain into the sewer system. Ponding may occur around homes where the ground is saturated.

City crews have been working to clear catchbasins in advance of the storm in order to minimize the risk of road flooding. Residents can assist by removing debris from catchbasins on local roads in their community. In addition, crews will continue to patrol areas that have been susceptible to flooding the past. Residents are asked to call 311 to report any instances of road flooding.

The storm sewer under Lower Simcoe underpass has been affected by Lake Ontario’s high water level. Current water levels are above the usual catchbasin threshold. As a result, that area has experienced ponding on the road. Toronto Water has implemented a temporary repair but the anticipated precipitation starting later today and continuing tomorrow could result in temporary flooding of this area again. Toronto Water will continue to monitor the underpass.

All parts of Toronto can be affected by flooding and there may be little or no advance warning that localized flooding is imminent. Flooding is most likely to occur in areas that have historically experienced frequent flooding such as the Don River Valley, the eastern and western beaches, the Toronto Islands, and other lakefront/shoreline areas.

Basement Flooding

  • Residents should call 311 immediately to report basement flooding. Toronto Water crews are available 24/7 to respond to flooding calls.
  • Clear catch basins and eavestroughs around the home.
  • Consider moving valuables to shelves or upper floors if flooding is imminent. Cleaners, paint, or chemicals should be removed from the floor to prevent contamination of floodwater that may enter the home.
  • During an extreme storm, reduce use of water in the home (avoid doing laundry or washing dishes) to prevent water from entering the sewer system, which can become overwhelmed during severe wet-weather events.

More information about basement flooding, including subsidies available under the City’s Basement Flooding Protection Program, is available at

Update on Island and Beaches

City services and facilities in Toronto Island Park are currently closed or are operating at reduced levels until further notice. The City is taking steps to support Toronto Island residents. Updates and further information are available at or by calling 311.

Five City-managed beaches – Cherry Beach Park, Rouge Beach Park, Woodbine Beach Park, Toronto Island Park, and Marie Curtis Park – have already experienced flooding this week. Public access to and use of these areas is restricted. Toronto’s Parks, Forestry, and Recreation division is working closely with TRCA to complete remediation work such as bolstering and/or repairing stone break walls and redistributing sand where appropriate to mitigate harmful erosion.

The Toronto and Region Conservation Authority ( is monitoring local watersheds for possible flooding.

May 2017