The Institute for Catastrophic Loss Reduction (ICLR) and Insurance Bureau of Canada (IBC) have a long-standing partnership in helping to protect Canadians from natural hazards. Together, they’ve collaborated on this series of IN Focus articles, which share tips to help you protect your home and property from some of Canada’s most damaging weather.
ICLR specializes in disaster prevention and has conducted extensive research to identify the most impactful steps homeowners can take to withstand winter storms, wildfire, severe wind, earthquake, basement flooding and hail.
In the next edition of the “Good, Better, Best Protection” IN Focus series, ICLR and IBC share tips and info on protecting your basement from flood.
Top basement flood protection tips
It’s every homeowner’s nightmare to discover that water from a recent rainfall has found its way into their lower-level rec room or storage nook. Yet homes across Canada, particularly in urban areas, are increasingly at risk of flooded basements and/or sewer backup. Short-duration, high-intensity rainfalls, caused by warmer temperatures, are leading to more frequent and severe flooding events. These storms can overwhelm municipal infrastructure, especially in older neighbourhoods with outdated stormwater systems.
Ontario experienced over $1 billion in insured damage from floods in 2024 – the second-costliest summer for flooding in the province’s history. In 2023, an atmospheric river event led to significant flooding in parts of Nova Scotia and is estimated to have caused over $170 million in insured damage. The severe downpour produced more than 250 millimeters of rain in the hardest-hit areas, most of that in fewer than 24 hours, leading to a provincial state of emergency, significant infrastructure damage, and flooding of homes and businesses.
The “good, better, best” tiered approach helps homeowners know what improvements to prioritize. While homeowners should take every possible essential precaution, time and budget constraints can get in the way of doing more. The enhanced measures are for those able to take their home’s flood resilience to the next level, and the comprehensive steps are for those who need the best possible protection.
While spring is peak flood season, heavy precipitation can happen at any time of year. Whether homeowners are up against rain, snow, sleet or drizzle, ICLR’s recommendations can help keep the water out.
Essential (good): Reverse the flow
Grade your lot to direct water away from your home.
Install a backwater valve with at least a 2% grade and maintain it at least once a year.
Disconnect foundation drains that are connected to sanitary or combined sewers and install a sump pump system with a battery backup and alarm.
Replace any sump pump that is over 10 years old with a high-quality, appropriately sized pump with a pressure or pendulum switch.
Disconnect downspouts that are connected to sanitary or combined sewers to reduce the risk of sewer backup.
Enhanced (better): Seal the perimeter
Repair foundation drains if your home is exposed to repeated seepage flooding (e.g., water coming in through cracks in the foundation wall or basement floor).
Avoid planting near sewer laterals to prevent roots from blocking proper flow.
Identify and seal cracks and other openings in foundation walls.
Protect exterior stairwells by increasing the height of the ground or by installing curbs around them or enclosing them.
Comprehensive (best): Go for watertight upgrades
Remove reverse slope driveways, which create a direct path for stormwater to enter your basement. This could involve raising the base near the property, so it slopes away from the foundation or installing a trench drain.
Ensure that water drains away from basement windows. For example, install window wells with proper drainage and regrade soil around the window so the ground slopes away from the foundation.
Repair or replace sewer laterals that are in poor condition.
Check out ICLR’s Good/better/best basement flood protection checklist, or the “Protect Your Home from Basement Flooding” booklet, the ultimate stay-dry guide.
Every policy is different. Know what flood damage your insurance covers. Reach out to your insurance representative with any questions about your policy.
Flood insurance coverage is optional and typically covers specific types of water damage, such as that caused by the overflow of lakes, ponds or rivers, or surface water from heavy rainfall or melting snow that enters the home through windows and doors. However, water entering the home through cracks in the foundation, and basement walls is generally still excluded.
Damage to vehicles from wind or water may be covered if you purchased optional comprehensive coverage, which protects against non-collision losses such as flooding, hail, or falling objects.
Water damage in a basement due to a sewer backup is only covered if you have purchased specific optional sewer backup coverage.
In certain circumstances, homeowners who are unable to stay in their homes because of insured damage may be entitled to coverage for additional living expenses.
Visit ibc.ca for more information on flooding and insurance, including what to do if your home, car or business is damaged as a result of flooding, how to file an insurance claim, and what to do if your home has become unliveable after an insured loss.
More tips
For more information on how to protect your home from flood risks and water damage, watch IBC’s “Stay Protected” video on flood and water safety.
See the other “Good, Better, Best Protection” articles:
Your “Better, best” guide to wildfire protection
Good, Better, Best Hail Protection: Learn the most effective resilience strategies for your home
