15 minutes of checking now can prevent thousands in flood damage later
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Toronto's storm season runs roughly from April through October, with the heaviest rainfall events typically hitting between May and September. The time to check your flood protection is before the rain starts, not during it. This checklist covers everything you should inspect, test, and maintain before storm season. Most items take 5 to 15 minutes each and require no tools or plumbing experience. A few items require a licensed plumber. The goal is to catch problems while they are cheap to fix, not after they cause a flooded basement.
Pour a bucket of water into the sump pit until the float switch activates. Watch for three things: Does the pump turn on? If it does not, check the plug (it may have been accidentally unplugged), check the breaker, and check whether the float switch is stuck or jammed by debris. Does it pump the water out quickly? A healthy pump should empty the pit within 15 to 30 seconds for a standard bucket volume. If it is slow, the impeller may be clogged or the motor may be weakening. Does it shut off cleanly after the water is gone? If the pump keeps running after the pit is empty, the float switch is stuck in the on position. A pump that runs dry will burn out. Also check the discharge line outside. Walk to where the pipe exits the house and make sure the opening is clear of debris, ice (early spring), or dirt. Water should flow freely away from the foundation, not pool next to the house. If your pump is more than 7 years old, consider proactive replacement before it fails during a storm. A planned replacement costs $360 to $900. An emergency replacement after a flood costs the same for the pump plus $5,000 to $50,000 in water damage.
If you have a battery backup sump pump, test it by unplugging the primary pump and pouring water into the pit. The backup should activate and pump the water out independently. Check the battery charge indicator. Most backup systems have an LED or display showing battery health. If the battery is more than 3 to 4 years old, it may not hold enough charge to run through a long outage. Replace batteries proactively. If you do not have a battery backup and rely on a single primary pump, you have no protection during a power outage. Power outages and heavy storms often happen at the same time in Toronto. A battery backup installation costs $1,080 to $2,800 and is covered under the City of Toronto sump pump rebate (up to $1,750).
If you have a backwater valve installed, locate the access cover in your basement floor (usually a round or square cover near the main drain). Open the cover and visually inspect the flap. The flap should be clean, move freely, and sit in the open position during normal conditions. If you see debris, toilet paper, or grease on the flap, clean it off. A dirty flap may not close fully during a backflow event, allowing sewage into your basement. Test the flap by gently pushing it closed and releasing it. It should open freely when you let go. If the flap is stuck, corroded, or the gasket is deteriorated, schedule a professional inspection and cleaning ($90 to $200). A malfunctioning backwater valve provides zero protection. If you do not have a backwater valve and have experienced floor drain backups during rain, this is the single most important installation you can make. Cost: $1,440 to $2,600. City rebate: up to $1,250.
Clogged gutters cause water to overflow and pour directly along the foundation wall. This water can enter the basement through cracks, window wells, or by saturating the soil and overwhelming the weeping tile system. Clean all gutters and remove leaves, shingle grit, and debris. Check that downspouts are securely attached. Downspout extensions should discharge at least 1.8 metres (6 feet) from the foundation. If your downspouts dump water right next to the house, you are directing stormwater straight at your basement walls. Do not connect downspouts to the sanitary sewer. This is illegal in Toronto and contributes to sewer backups during storms. If your downspouts currently connect underground to the sewer system, have them disconnected and extended away from the house.
Walk around the outside of your house and look at the ground level next to the foundation walls. The soil should slope away from the house, not toward it. Over time, soil settles and can create low spots where water pools against the foundation. The recommended slope is at least 15 cm (6 inches) of drop over the first 1.8 metres (6 feet) from the foundation wall. If you see areas where water would pool against the house, add soil to restore the slope before storm season. Also check for any cracks in the foundation that are visible from the outside. Small cracks can be sealed with hydraulic cement or injectable polyurethane. Large cracks or cracks that show displacement may need professional assessment.
Basement window wells can fill with water during heavy rain if they do not drain properly. Check that each window well has clear drainage at the bottom (usually connected to the weeping tile or filled with gravel). Remove leaves and debris from the wells. If water pools in the well during normal rain, the drain is likely blocked. Window well covers (clear plastic or metal grates) keep out most rainwater and debris. If you do not have covers, they are inexpensive ($15 to $40 each at hardware stores) and significantly reduce the amount of water entering the well.
Pour water down every basement drain: floor drain, laundry sink, shower, and any utility drains. Watch for slow drainage, gurgling, or backup. Slow drains indicate buildup that could become a full blockage during the added volume of a storm. Schedule drain cleaning before storm season rather than during an emergency. If the floor drain trap has dried out (common in basements where the drain is rarely used), the sewer gas barrier is gone. Pour a litre of water down the floor drain to refill the trap. This also confirms the drain is flowing.
Call a licensed plumber if: Your sump pump failed the bucket test or is more than 7 years old. Your backwater valve flap is stuck, corroded, or you are not sure if you even have one. You have experienced any floor drain backup during rain in the past, even a minor one. Minor backups are warnings that a major one is coming. You have never had a camera inspection of your main sewer line and your home is more than 30 years old. A camera inspection ($180 to $400) can reveal root intrusion, partial blockages, bellies, or pipe deterioration that would cause a backup during the next heavy rain. You have a sump pump but no battery backup, and your area loses power during storms. For a pre-storm assessment, call 647-784-8448 or book online. The best time to discover a problem is before the storm, not during it.
How often should I test my sump pump?
At minimum, test it once before storm season (April or May) and once mid-season (July). If you are in a high-water-table area or have experienced flooding before, test monthly from April through October. The test takes 5 minutes: pour a bucket of water into the pit and verify the pump activates, empties the pit, and shuts off.
What is the most common cause of sump pump failure during a storm?
Power outage. The storm knocks out power, and the pump stops running at exactly the moment you need it most. A battery backup system ($1,080 to $2,800) is the fix. The second most common cause is a stuck float switch, which is why the bucket test matters.
How long does a sump pump battery backup last during a power outage?
Typical runtime is 4 to 12 hours, depending on battery capacity and how frequently the pump cycles. In a heavy storm with high water volume, the pump cycles more often and battery life is shorter. Batteries that are more than 3 to 4 years old hold less charge. Test and replace proactively.
Should I get a camera inspection before storm season?
Yes, especially if your home is more than 30 years old and you have never had one, or if you have experienced slow drains or minor backups. A camera inspection ($180 to $400) reveals root intrusion, partial blockages, pipe bellies, and deterioration that could cause a full backup during the next heavy rain. It is diagnostic, not preventive, but it tells you exactly what needs to be fixed.
What is the cheapest way to protect my basement from flooding?
The cheapest meaningful step is to clean gutters, extend downspouts, and fix grading around the foundation (free to $200 in materials). The cheapest device that provides real protection is a backwater valve ($1,440 to $2,600 installed), which drops to under $1,000 after the City of Toronto rebate. Combining a backwater valve and sump pump installation maximizes the rebate (up to $3,400) and provides comprehensive protection.