Floods & Precipitation

Nearly all of the 2,300 people surveyed for a new University of Waterloo study did not know or weren’t sure that they lived in a designated flood risk area. Almost 90% were unaware that their home was in an area vulnerable to flooding.

Floods can happen anywhere in a city

The combination of heavier rainfall on expanding areas of concrete and tarmac along with a higher density of people has made urban flooding a growing threat in cities across Canada.

The insurance industry once received the greatest number of claims from fire. Now it’s water. 

  • Water that cannot be absorbed into the ground through earth, grass and other permeable surfaces, flows on top of it. This floods roads, sidewalks and buildings
  • Inadequately sized and aging storm sewers backup when they’re overwhelmed by volumes of rainwater. This floods basements. 
  • Poorly graded land sends water from higher ground to lower levels. This floods the buildings below. 
  • Heavy rain can overwhelm sewage treatment plants. Untreated sewage pours into freshwater lakes and rivers contaminating the water.  

Where do you live?

If you live in a rental unit, especially a basement, you are at risk of serious damage to your property. Your landlord is not responsible for your personal property. You need content insurance. 

The electrical rooms of high rise apartment buildings are often located at the basement or ground level. They are at risk of flooding that  can cause sometimes lengthy power outages. If you live above the eighth floor you may lose your water supply. You should be prepared to look after yourself and your family with an emergency kit and plan.

If you own your house many cities have subsidy programs for flood protection. Useful tips on protecting your property are also widely available.

Protective action is often a small investment – especially if you keep anything of personal value in your basement.

Overland Flooding

Floods can occur in any region of Canada, at any time of the year

Overland flooding comes from water that flows over the ground. That’s often caused by melting ice and snow in the spring and overflowing rivers. Extreme rainfall that is not absorbed into the ground can also cause overland flooding. 

Flooding also takes place along lake and coastal shorelines, when higher than normal water levels inundate low-lying areas.

Preparedness Strategies

  1. Pay attention to extreme rain warnings.
  2. Do not try to swim or drive through floodwater.
  3. Prepare for power outages with an emergency kit and plan. If you live above the eighth floor you may lose your water supply.
  4. Pay attention to public health alerts.
  5. Don’t eat food that may have been contaminated by floodwater.
  6. Mold can spread very quickly. Get professional help to remove it — fast!
  7. Look out for neighbours and people in your community who may need help protecting themselves. Check in and make sure everyone is safe.

Public Health Impacts

Drowning: Most deaths from flash floods are people who drown while trying to swim away or while trapped in flooded buildings.

Driving: Misjudging how deep the water is and how quickly the current is moving.

Injuries: Heavy objects move quickly through floodwater. Flooded buildings can have damaged wiring and electrical appliances that could electrocute people or cause fires. In any season most floodwater is well below normal human body temperature and can cause hypothermia.

Diseases spread through water contamination and sewage backup. Heavy rain can result in contaminated drinking water. Floodwater can mix with pollutants and can contaminate local waterways that supply drinking water. Combined sewer systems can overflow and contaminate waterways. Combined sewer systems can also back up into household plumbing and increase the risk of contaminating food and water.

Diseases spread through food contamination: Food contamination and related illness can occur following flooding and power outages given that temperatures required to keep food safe may not have been maintained or that food may have come into contact with contaminated water.

Diseases spread by insects: Mosquitoes breed in still water that collects after heavy rainfall. This can result in outbreaks of diseases carried by mosquitos, such as West Nile virus.

Mold is a major health problem caused by floods.

Flooding Infographic

Click on the image to enlarge the infographic for reading.

Flooding infographic with detailed information about flooding in Canada.


Tenant insurance

Content Insurance for Tenants – Informative blog by Ashley Tonkens for the website Cansumer. Includes the average cost of tenant insurance by province and what it covers.

Basic information from the Insurance Bureau of Canada (IBC)

Resources from the Intact Centre for Climate Adaptation

Report on Flood Preparedness of Canadian Cities (PDF)

Flood Protection Subsidy Programs (PDF) – Many Canadian cities offer some help. Check to see if yours has a program. 

How to protect your home from flooding –  Resources for homeowners

Other Resources

How likely is flooding where you live? General overview of the likelihood of flooding in your Canadian region. Think Hazard maps

West Carleton Disaster Response – Wonderful Community Organization formed in response to flooding and tornadoes. Ontario small town, rural. 

Unflood Ontario – Green infrastructure to mitigate flooding.  Small grants.

How the resilience of communities to climate change in the UK is currently understood and practised. Includes great examples of community and government initiatives in the UK.