A severe rainstorm can turn an ordinary Toronto street into a dangerous flooded area surprisingly quickly. Water may collect beneath railway bridges, enter basement apartments, disrupt TTC routes and cause power outages before residents have much time to react.
Flash flooding is especially confusing for newcomers who may not know Toronto’s emergency numbers, flood-prone locations or the difference between a weather warning and a flood message.
This Toronto flash flood safety guide explains what residents should do before heavy rain begins, while flooding is happening and after the water recedes.
Why Flash Flooding Happens in Toronto
Toronto contains paved roads, parking lots, buildings and other surfaces that prevent rain from soaking naturally into the ground. During an intense storm, large volumes of water can reach storm drains faster than the drainage system can carry them away.
Local flooding can develop around:
- Road underpasses and low-lying intersections
- Basement apartments
- Underground parking garages
- Rivers, ravines and trails
- Subway entrances and transit stations
- Properties with blocked drains or sewer backups
Flood conditions can vary greatly between neighbourhoods. Your street may appear relatively dry while an underpass or ravine only a few blocks away is already unsafe.
Before Heavy Rain Reaches Toronto
Preparation does not have to involve expensive emergency equipment. The most useful first step is knowing where you will get reliable information.
Monitor weather warnings issued by Environment and Climate Change Canada and flood messages published by the Toronto and Region Conservation Authority. TTC riders should also bookmark the TTC service alerts page.
Charge your phone and portable battery before the storm arrives. Keep a flashlight, necessary medication, identification, drinking water and basic first-aid supplies somewhere that can be reached without going into a basement.
People living in basement apartments should identify the fastest safe exit. Make sure windows and doors used as emergency exits can open properly and are not blocked by furniture or stored belongings.
Move important documents, electronics, photographs and valuable possessions away from the basement floor. A waterproof container or sealed plastic pouch can protect passports, immigration papers, insurance documents and rental records.
Renters should save the contact information for their landlord, superintendent or property manager. Condo residents should know how to reach building security or management after regular business hours.
Preparing for emergencies can add small costs to a household budget. Our guide to monthly expenses in Toronto can help newcomers account for emergency supplies and tenant insurance when planning their finances.
What to Do When Flash Flooding Begins
Your first priority is getting away from rising or moving water. Do not delay leaving a dangerous area to collect belongings, move a vehicle or record a video.
Floodwater can hide open maintenance holes, damaged pavement, sharp objects and electrical hazards. It may also contain sewage or other contaminants.
Never walk, cycle or drive through a flooded road. The water may be deeper or faster than it appears. Toronto’s underpasses are particularly risky because water can accumulate rapidly with limited room to turn around.
The TRCA’s flood safety guidance advises residents to stay away from riverbanks, watercourses and low-lying areas during storms. That includes ravines, waterfront trails, culverts and pedestrian paths beside streams. Keep children and pets away as well.
If someone falls into fast-moving water, call 911. Entering the water to attempt a rescue can place both people in danger.
If You Are Driving
Turn around when you see water covering the road. Do not follow another vehicle through it, even if that vehicle appears to cross safely.
Avoid low-lying routes and underpasses during intense rainfall. If water begins rising around your vehicle and you can safely reach higher ground on foot, leave the vehicle. Call 911 if you are trapped or in immediate danger.
Traffic lights may stop working during a power outage. Treat an intersection with non-functioning signals as an all-way stop and proceed cautiously.
For everyday travel planning beyond storm conditions, consider whether a shorter Toronto commute could reduce your dependence on routes that regularly become congested or disrupted during extreme weather.
If You Use the TTC
Heavy rain may cause station closures, bus diversions, slow subway service or interruptions along outdoor portions of the network.
Check official TTC alerts before leaving. Do not assume that a normal route will remain available throughout the storm. Allow additional time and identify an alternative that does not require walking through a flooded underpass or along a ravine.
Follow instructions from TTC employees if water enters a station. Do not cross barriers or enter a closed section to reach a platform. If a station entrance is flooded, use another entrance only if TTC staff or official updates indicate that it is open and safe.
If Water Enters Your Basement
Do not enter a flooded basement until you know the electricity has been disconnected. Water near outlets, appliances or an electrical panel can create a risk of severe shock or electrocution.
Toronto Hydro advises residents whose flooded basement still has power to call 416-542-8000 to request disconnection. Never stand on a wet or damp floor to unplug an appliance, operate a breaker or reach an electrical panel. See Toronto Hydro’s outage and flood guidance for current instructions.
If you live in a basement apartment and water begins rising, leave immediately when it is safe to do so. Take your phone, medication, keys and identification only if they are within easy reach. Warn other occupants and contact the landlord or property manager after reaching a safe location.
Call 911 if someone is trapped, injured or facing an immediate electrical, fire or structural danger.
The City asks residents to report basement flooding and sewer backups to 311. Tenants should also notify their landlord or superintendent in writing. If a sewer backup may have caused the flooding, minimize the use of toilets, sinks, dishwashers and washing machines until the problem has been assessed. The City explains these steps on its basement flooding information page.
Elevators and Underground Parking
Do not use an elevator when a building is flooding or experiencing an unstable power supply. An elevator can stop between floors if electricity fails. Use stairs when building staff confirm that the stairwell is safe.
Never enter a flooding underground garage to retrieve a vehicle. Garage ramps can channel water downward, and conditions below ground may be much worse than they appear from the entrance.
Contact building management if water is entering the garage. Call 911 when flooding creates an immediate danger to occupants.
Who Should You Contact?
Use 911 for situations involving immediate danger to life, a trapped person, a serious injury, fire or an urgent electrical hazard.
Use 311 to report basement flooding, sewer backups, blocked catch basins and other non-life-threatening City service problems. A request can also be submitted through Toronto 311.
Contact Toronto Hydro at 416-542-8000 when a flooded basement still has electrical power or when you see a damaged power line or other electrical hazard. Remain well away from downed wires.
Renters should contact their landlord, superintendent or property manager once they are safe. Condo residents should notify building management or security.
What to Do After the Water Recedes
Do not assume an area is safe simply because the rain has stopped. Rivers and streams may continue rising after a storm, while roads, trails and riverbanks may remain unstable.
Wait for official instructions before returning to an evacuated property. In an apartment or condo, ask management whether the building’s electricity, elevators and underground areas have been inspected.
If it is safe to enter, photograph and record the damage before moving items or beginning cleanup. Capture the water line on walls, damaged flooring, affected possessions and the apparent source of the water. Save written messages to your landlord, building management, 311 and your insurer.
Contact your insurance provider as soon as reasonably possible. Ask what documentation it requires and whether you must wait for an adjuster before discarding damaged property. Keep receipts for emergency accommodation, transportation, food and necessary replacement purchases.
A landlord’s insurance generally protects the building rather than a tenant’s personal belongings. Renters should check their own tenant insurance policy to understand whether water damage, sewer backup or temporary accommodation is covered.
Treat Floodwater as Contaminated
Water that entered through a sewer, floor drain, street or overflowing watercourse may contain bacteria, chemicals and sharp debris.
Avoid direct skin contact. Keep children and pets away from affected rooms and belongings. Do not consume food, medicine or cosmetics that came into contact with floodwater.
Wet electrical appliances, outlets and breaker panels should not be used until they have been inspected by a qualified professional. Materials that remain wet can also develop mould, so drying and assessment should begin as soon as the area is electrically and structurally safe.
Inspect the Home for Continuing Problems
Look for cracks, warped walls, sagging ceilings, damaged flooring and persistent sewage odours. Leave the property and request professional assistance if you notice structural movement, unusual sounds or signs that walls or ceilings may collapse.
Tenants should send their landlord a written description of the damage and request a timeline for inspection and repairs. Keep copies of messages and photographs in case questions arise later about the condition of the rental.
Homeowners can review the City’s basement flooding prevention information to learn about grading, downspouts, sump pumps and backwater valves. Eligibility and subsidy amounts can change, so confirm the current rules before arranging work.
Learn From the Flood Before the Next Storm
Once the immediate problem is resolved, consider what would make the next warning easier to manage.
That might mean moving valuables permanently off the basement floor, improving your emergency contact list, purchasing tenant insurance, arranging a backup place to stay or choosing a safer route home during heavy rain.
Residents who enjoy Toronto’s parks and ravines should remember that familiar trails can become dangerous during and immediately after a storm. When planning future outings, our guide to exploring Toronto like a local can help you discover alternatives away from affected areas.
Flash flooding develops quickly, but a few practical decisions can substantially reduce your risk. Follow official warnings, stay away from moving water, leave basement areas when conditions worsen and never place possessions or a vehicle ahead of personal safety.
Note: This guide provides general safety information and does not replace instructions from emergency services, the City of Toronto, TRCA, Toronto Hydro, the TTC or your building’s emergency personnel. Call 911 whenever someone is in immediate danger.