Flooding is the most costly natural hazard in Ontario and it can happen at any time of year.
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Floods are the costliest natural hazard in terms of property damage in Ontario. Floods are typically caused by melting snow, ice jams, high lake levels, and heavy rains and thunderstorms. They can happen at any time of year and in urban and rural areas. Flash flooding can occur in rain storms or when a storm drain is plugged – often with little or no warning.
Flood forecasting and warning program
Flooding in Ontario is caused by extreme rain, rapid snowmelt, lake/storm surge or ice jams.
If you are instructed by emergency officials to evacuate, do so immediately.
If you are indoors:
- ensure necessary personal items (medications, and important documents) are secured and easily accessible in case of evacuation
- disconnect electrical appliances — don’t touch electrical equipment if wet or standing in water
- don’t eat food that’s come in contact with flood waters
- ensure your cellphone is charged (safely) – it may be your only means of communication during an evacuation
If you are outdoors:
- if your property is impacted by flooding:
- and your electricity is on, leave the area immediately
- follow your emergency plan and move to a safe place on higher ground
- avoid travelling on roads that are near water, bridges, ravines, embankments, low laying areas and any bodies of water
- don’t drive through, stand or walk in any moving water – you may fall
- if you must walk, look for where the water is not moving and use a stick to check the ground in front of you
- account for all of your family members, keeping children and pets away from floodwaters
What you can do
Before a flood
Inside your home:
- store any personal belongings in sealed bins
- move documents and keepsakes out of the basement
- test sump pumps regularly and install a back-up system (for example, battery back-up or generator)
- put weather protection sealant around basement windows and ground-level doors
check valvesin sewer traps to prevent floodwater from backing up into the drains of your home
Outside your home:
- extend downspouts at least 2 metres from your home to move water away from the building
- remove debris that could present danger during flood events
- secure outdoor furniture and items around piers, docks or boathouses
- regularly maintain water drainage systems, such as weeping tile, culverts and ditches
During a flood
If you are instructed by emergency officials to evacuate, do so immediately. If an evacuation is not in place, consider these safety precautions:
- avoid travelling on roads that are near any bodies of water
- don’t drive through, stand or walk in any moving water
- if you must walk, look for still water and use a stick to check the ground in front of you
- keep children and pets away from floodwater
- avoid using the plumbing system if the septic tank or the disposal field is under water
After a flood
Before returning home, check with your local municipality for any information from local public health units, utilities and other community officials who are working to keep you and your family safe.
- Don’t use flooded appliances, electrical outlets, switch boxes or fuse breaker panels until they have been checked by your local authority.
- Follow instructions from your local public health unit when it comes to water in and around your home, which could be heavily contaminated.
- Don’t eat food that’s come in contact with flood waters.
- Contact your local municipality about debris management programs.
- Report any broken utility lines to the appropriate authorities.
- If your property has been damaged:
- For on-the-ground flood response, such as providing sandbags and debris removal, visit your municipality’s website
- For local flood information, visit your local conservation authority’s website
- For communities not serviced by a conservation authority, contact your local MNRF district office
- For First Nation communities, please contact Indigenous Services Canada.
- To plan your route in an event of a flood and for travel safety, call or visit 511.
- Find the latest flood condition information in Ontario at Surface Water Monitoring Centre