Updated October 2026

Spring is a welcome season for Ontario homeowners. Warmer temperatures, longer days and melting snow signal the end of another winter.

Unfortunately, spring can also bring an increased risk of water damage.

Melting snow, heavy rainfall, frozen ground and blocked drainage systems can all contribute to water entering a home.

Basement flooding, sewer backups and water seeping through foundation walls can result in extensive damage to flooring, furniture, appliances and personal belongings.

The cleanup can be disruptive, and repairs may take weeks or even months.

While homeowners cannot control the weather, there are steps they can take to reduce the risk of water damage.

At L.D. Dermody Insurance Brokers, we encourage homeowners to take preventive measures before the spring thaw and to understand how their home insurance responds to different types of water damage.

1. Why Is Spring a High-Risk Season for Water Damage?

Several conditions can combine to create water problems during the spring.

Melting Snow

As temperatures rise, accumulated snow begins to melt.

If large amounts of snow melt quickly, the resulting water must find somewhere to go.

When drainage systems cannot keep up, water may accumulate around foundations, enter window wells or flow toward basement openings.

Heavy Rainfall

Spring storms can produce substantial rainfall.

When rain falls on already saturated or frozen ground, the water may not be absorbed quickly enough.

Instead, it can collect on the surface and move toward lower areas, including basements.

Frozen Ground

Even when the air temperature is above freezing, the ground may remain frozen.

Frozen soil can prevent melting snow and rainwater from soaking into the ground.

This increases surface runoff and can contribute to water collecting near buildings.

Blocked Drainage Systems

Leaves, ice, debris and sediment can obstruct eavestroughs, downspouts, catch basins and other drainage systems.

When water cannot drain properly, it may overflow or be redirected toward the home.

Understanding these risks is the first step toward preventing damage.

2. Keep Snow Away From Your Foundation

One of the simplest preventive measures is to manage snow accumulation around your home.

Large snowbanks against foundation walls can create problems when temperatures rise.

As the snow melts, water may collect beside the building.

If the ground slopes toward the foundation or drainage is poor, the risk increases.

Where it can be done safely, consider moving excess snow away from the foundation before a major thaw.

Pay particular attention to:

• Basement windows.

• Window wells.

• Walkout basement entrances.

• Exterior stairwells.

• Areas where water has accumulated in previous years.

Make sure that melting snow has a clear drainage path away from the home.

Avoid directing runoff toward neighbouring properties.

3. Inspect Your Eavestroughs and Downspouts

Eavestroughs and downspouts are important parts of your home's drainage system.

Their purpose is to collect water from the roof and direct it away from the foundation.

When they are clogged, damaged or improperly positioned, water can overflow and accumulate near the building.

Before the spring rains arrive, check for:

• Leaves and debris blocking eavestroughs.

• Loose or damaged sections.

• Downspouts that have become disconnected.

• Ice or other obstructions.

• Water draining directly beside the foundation.

Downspout extensions may help carry water farther from the home, provided they are installed in accordance with local requirements and do not create drainage problems elsewhere.

If your home has underground downspout connections, ensure they are functioning properly.

For safety, consider hiring a qualified contractor for work that requires climbing ladders or accessing the roof.

4. Check the Grading Around Your Home

The ground surrounding your home should generally direct surface water away from the foundation.

Over time, soil can settle, landscaping can change and low spots can develop.

These areas may allow water to collect against foundation walls.

Walk around your property and look for:

• Depressions beside the foundation.

• Soil that slopes toward the house.

• Water pooling after rainfall.

• Areas where landscaping obstructs drainage.

• Cracks or gaps near foundation walls.

Improving the grading may help reduce the amount of water reaching the foundation.

However, grading changes should be planned carefully.

Municipal drainage rules, neighbouring properties and existing drainage systems may affect what work is appropriate.

For significant drainage problems, consult a qualified contractor.

5. Inspect Basement Windows and Window Wells

Basement windows and window wells can be vulnerable during spring runoff.

A window well that fills with water can place pressure against the window and potentially allow water to enter the basement.

Check that window wells are clear of leaves, snow, ice and other debris.

If a window well has a drain, make sure it is functioning.

Inspect basement windows for damaged seals, cracks or other visible problems.

Window well covers may help reduce the accumulation of debris and some precipitation, but they are not a substitute for proper drainage.

If water has entered through a basement window in the past, investigate the underlying cause before the next major storm.

6. Test Your Sump Pump Before the Spring Thaw

Homes with sump pumps should have them inspected and tested regularly.

A sump pump is designed to remove water that collects in a sump pit, helping prevent it from accumulating in the basement.

However, a sump pump is only useful if it operates when needed.

Before spring, consider checking:

• Whether the pump turns on and off properly.

• Whether the float switch moves freely.

• Whether the discharge line is clear.

• Whether the pump is connected to a suitable electrical supply.

• Whether water is being discharged to an appropriate location.

• Whether the sump pit contains excessive debris.

Follow the manufacturer's instructions when testing or maintaining the pump.

If you are uncertain about its condition, arrange for a qualified professional to inspect it.

What Happens During a Power Outage?

Heavy storms can sometimes cause power failures.

Unfortunately, this may happen at the same time your sump pump is needed most.

A battery backup sump pump or other suitable backup system may provide additional protection.

Some homeowners also install water alarms that provide an alert when water is detected.

These measures cannot eliminate the risk of flooding, but they may help reduce the likelihood or severity of damage.

7. Consider Installing a Backwater Valve

A backwater valve is a plumbing device designed to help prevent sewage from flowing backward into a building through the drainage system.

During heavy rainfall or other conditions that overload municipal sewer systems, wastewater can sometimes back up toward connected properties.

A properly selected, installed and maintained backwater valve can help reduce this risk.

However, it is important to understand that a backwater valve is not a guarantee against all basement flooding.

It does not prevent every type of water entry, including surface water entering through doors or windows or water seeping through foundation walls.

Backwater valves also require appropriate installation and maintenance.

Is Financial Assistance Available?

Some Ontario municipalities offer financial assistance or rebate programs for eligible homeowners who install backwater valves, sump pumps or other flood-prevention measures.

Programs, eligibility requirements and funding availability vary by municipality.

Before arranging installation, contact your municipality to determine whether a program is available and whether approval is required before work begins.

A qualified plumbing contractor can help assess whether a backwater valve is appropriate for your property.

For more information, see our article about backwater valves and the role they can play in preventing sewer backup losses.

8. Look for Foundation Cracks and Signs of Seepage

Small foundation cracks may allow water to enter a basement, particularly when the surrounding soil is saturated.

Some cracks are primarily cosmetic, while others may indicate a more significant issue.

Watch for signs such as:

• Damp patches on basement walls.

• Water stains.

• Peeling paint.

• White mineral deposits on masonry.

• Musty odours.

• Repeated dampness after rainfall.

• Visible cracks that appear to be changing.

Do not ignore recurring moisture problems simply because the amount of water seems small.

Over time, moisture can damage building materials and contribute to mould growth.

If you suspect foundation leakage, have the problem assessed by a qualified professional.

9. Check Your Roof for Winter Damage

Ontario winters can be hard on roofs.

Snow, ice, wind and repeated freezing and thawing can damage shingles, flashing and other roofing materials.

When spring rain arrives, existing damage may allow water to enter.

From a safe location, look for visible concerns such as:

• Missing or damaged shingles.

• Loose flashing.

• Damaged roof vents.

• Sagging or damaged eavestroughs.

• Signs of water staining in the attic or upper floors.

Do not climb onto a roof if conditions are unsafe.

A qualified roofing contractor can perform a more thorough inspection.

Regular roof maintenance is important because insurance is generally intended to respond to insured events, not ordinary deterioration or a lack of maintenance.

For more information, see our article Check Your Roof: Why Regular Maintenance Matters for Your Home Insurance.

10. Understand the Different Types of Water Damage

One of the most important things homeowners should understand is that insurance companies distinguish between different causes of water damage.

The cause of the water entering the home can determine whether a claim is covered.

Sudden and Accidental Escape of Water

Many home insurance policies provide coverage for certain sudden and accidental water losses, such as a burst interior plumbing pipe.

However, coverage depends on the policy wording, circumstances and applicable exclusions.

Sewer Backup

Sewer backup generally involves water or sewage backing up through drains, toilets or other plumbing fixtures.

Coverage for sewer backup often requires a specific endorsement or coverage option.

Availability, limits and deductibles vary by insurer.

Overland Water

Overland water coverage is intended to address certain types of water entering a home from above-ground sources, such as heavy rainfall or overflowing bodies of freshwater.

The precise definition, coverage and exclusions vary.

Not all properties qualify for overland water coverage, and some insurers impose restrictions or special limits.

Groundwater and Seepage

Water entering through foundation walls, floors or other openings may be treated differently from sudden and accidental water damage.

Gradual seepage, ongoing leakage and water infiltration may be excluded.

Some insurers offer additional groundwater-related coverage, but it is not universally available.

Flooding

The word flooding is often used to describe almost any situation where water enters a home.

However, insurance policies use more specific definitions.

A flooded basement caused by a sewer backup may be treated differently from one caused by overland water or foundation seepage.

Two homes on the same street can experience water damage during the same storm and have different insurance outcomes because the water entered in different ways.

For more information, see our articles Are You Covered for Water Damage? and Flood Damage – Frequently Asked Questions.

11. Does Every Homeowner Have Sewer Backup and Overland Water Coverage?

No.

These coverages should not be assumed to be included automatically.

Some insurance companies offer sewer backup and overland water coverage as optional endorsements.

Others may include certain coverage within broader packages, subject to conditions.

Coverage may be unavailable or restricted for properties with particular risk characteristics.

Insurers may also apply different deductibles and coverage limits.

For example, a homeowner could have a substantial amount of insurance on the dwelling but a lower limit for certain water damage losses.

It is important to review not only whether the coverage exists, but also how much protection is available.

Ask your broker to explain the applicable limits, deductibles and exclusions.

12. Can Preventive Measures Affect Your Insurance?

Some insurance companies consider water damage prevention measures when evaluating a property.

Depending on the insurer, information about sump pumps, backwater valves and other protective systems may affect eligibility, underwriting requirements or available discounts.

However, not every insurer offers a discount for these installations.

A backwater valve or sump pump also does not automatically guarantee eligibility for sewer backup or overland water coverage.

If you install new flood-prevention equipment, advise your insurance broker.

Your insurer may want to know what was installed and may request supporting documentation.

Keep copies of invoices, permits and inspection records where applicable.

13. What Should You Do if Water Enters Your Home?

Even with preventive measures, water damage can still occur.

If you discover water entering your home, take appropriate steps to protect people and prevent further damage.

Put Safety First

Do not enter standing water if there may be an electrical hazard.

Avoid contact with sewage-contaminated water.

If necessary, contact emergency services or qualified professionals.

Take Reasonable Steps to Limit the Damage

If it is safe to do so, stop the source of water, move undamaged belongings away from affected areas and arrange appropriate emergency assistance.

Do not attempt repairs or cleanup that could put you at risk.

Document the Damage

Take photographs or videos showing the affected areas and damaged belongings.

Keep records of emergency work and expenses.

Contact Your Insurance Broker or Insurer

Report the loss promptly and ask about the claims process.

Your insurer may arrange an adjuster or provide instructions about emergency cleanup and repairs.

Keep Damaged Items Until You Receive Guidance

Where practical and safe, avoid discarding damaged property before documenting it and discussing the situation with the insurer.

Items that present a health or safety hazard may require immediate removal.

Do Not Delay Necessary Emergency Work

Reasonable steps to prevent additional damage may be necessary before an adjuster can attend.

Keep receipts and records, and communicate with the insurer as soon as possible.

14. A Spring Water Damage Prevention Checklist

Before the snow begins to melt, consider the following:

• Clear snow away from vulnerable foundation areas.

• Remove debris from eavestroughs and downspouts.

• Make sure downspouts direct water away from the home.

• Check that the ground slopes away from the foundation.

• Inspect basement windows and window wells.

• Test the sump pump.

• Consider a suitable sump pump backup system.

• Check for foundation cracks and signs of moisture.

• Inspect the roof for visible winter damage.

• Keep exterior drains and drainage paths clear.

• Review your sewer backup and overland water insurance coverage.

• Keep important belongings off basement floors where practical.

• Know how to contact your insurance broker or insurer if a loss occurs.

Taking these steps before spring weather arrives may help reduce the risk of an expensive and disruptive water damage claim.

Prevention and Insurance Work Together

Water damage is one of the more serious risks facing Ontario homeowners.

Heavy rainfall, rapid snowmelt and drainage problems can affect properties that have never experienced flooding before.

Good maintenance and preventive measures can help reduce the likelihood of water entering your home.

However, even a well-maintained property can suffer water damage during severe weather.

That is why prevention should be combined with an appropriate insurance review.

At L.D. Dermody Insurance Brokers, we can help Ontario homeowners understand the water damage coverage available through the insurance companies we represent.

We can also help you review your existing policy to determine whether sewer backup, overland water or other water damage coverages are included and what limits or restrictions apply.

If you are unsure how your home insurance would respond to spring flooding or water damage, contact L.D. Dermody Insurance Brokers. We would be pleased to help you review your coverage before a loss occurs.

This article provides general insurance information for Ontario homeowners as of October 2026. Insurance coverage, eligibility, limits, deductibles, conditions and exclusions vary by insurer and policy. Municipal flood-prevention programs and requirements also vary by location. Always refer to your policy wording and consult qualified professionals regarding drainage, plumbing and structural concerns.