Extreme weather events are becoming more common across Canada, and flooding remains the most frequent hazard homeowners face. While flooding can feel unpredictable, understanding how and why it happens is the first step toward protecting your home.
As winter transitions into spring, flood risk often increases. Melting snow, frozen or saturated ground, and early-season rainstorms can combine to overwhelm drainage systems and waterways. This seasonal shift makes late winter and early spring one of the most critical times for homeowners to understand and prepare for potential flooding.
At CAA Niagara, we believe informed Members are empowered Members. That’s why we’re sharing practical, easy-to-understand information to help you recognize flood risks and take proactive steps to reduce potential damage.
Before you can take steps to protect your home, it’s important to understand how water can find its way inside. Flooding isn’t caused by just one scenario—it can come from several sources, sometimes at the same time.
Fluvial Flooding – Occurs when rivers, creeks, or streams overflow their banks, often after prolonged rainfall or rapid snowmelt.
Pluvial Flooding – Happens when heavy rainfall overwhelms drainage systems, causing water to pool on the surface. This type of flooding can occur even when there’s no nearby body of water.
Groundwater Flooding – Occurs when underground water levels rise and push water into basements through cracks in foundations, walls, or floors. This is most common during the transition from winter to spring, when snow and ice melt faster than the ground can absorb moisture.
Coastal Flooding – Caused by high winds, storm surges, rising water levels, or wave action along shorelines, including large lakes such as the Great Lakes.
Flooding often results from several conditions happening at once. Some of the most common contributing events include:
Snowmelt Runoff – Rapid warming can cause large volumes of melting snow to overwhelm rivers and drainage systems. Frozen ground prevents water from absorbing into the soil, increasing flood risk.
Heavy Storms and Rainfall – Intense rainfall over a short period can overwhelm both natural and built drainage systems, leading to flash flooding within hours of a major storm.
Ice Jams – Ice buildup in narrow or curved sections of rivers can block water flow, forcing water over riverbanks—often suddenly and without warning.
Natural Dams – Landslides, moraines, or glaciers can block waterways, causing water to back up and flood surrounding areas.
Structure Failure – While rare, flooding can occur if dams, dykes, or levees fail due to excess water, aging infrastructure, or natural events.
Urban Flooding – Paved surfaces in cities prevent water from soaking into the ground. During heavy rain, storm drains can become overwhelmed, allowing water to flow into streets and homes.
Infrastructure-Related Flooding – Sewer systems can become overloaded during storms, causing sewage to back up into homes when water has nowhere else to go.
Flooding can feel complex, but there are practical actions homeowners can take to help reduce risk—especially before spring thaw and heavy rain seasons.
Inspect Your Foundation – Look for visible cracks or gaps where water could enter and seal them using waterproof materials.
Check Your Grading – Ensure the ground around your home slopes away from the foundation to help direct water safely away.
Keep Drainage Clear – Regularly clean gutters, downspouts, and nearby sewer grates to help prevent water buildup and overflow.
Flood risk may be increasing, but being informed puts you in a stronger position to protect your home. Understanding how flooding happens helps you make smarter decisions about maintenance, preparedness, and prevention.
For more practical guidance, explore our blog Protecting Your Home Against Flooding: Preventative Maintenance, where we break down proactive steps you can take today to help safeguard your home.
At CAA Niagara, we’re here to help Members stay informed, prepared, and confident—no matter what the weather brings.