Experiencing a basement flood can result in significant financial losses for homeowners, as it causes extensive damage to personal belongings and requires substantial efforts to rehabilitate and replace items lost. Thus, it is in the best interest of homeowners to prevent basement flooding altogether, given its widespread occurrence and associated costs. 

Initial Understanding and Knowledge

Gaining knowledge and a thorough understanding of various aspects, such as the flood risk in your locality, the level of awareness of the authorities, insurance considerations, and the functioning of your residential plumbing and drainage systems, are essential to minimize the chances of basement flooding. The subsequent segment outlines five measures that can help enhance your understanding of flood risks and their consequences.

Reach Out to The Municipality of Toronto for Basement Flooding

Whether or not your home has experienced basement flooding, Toronto municipality is a good place to start. We recommend you check Toronto.ca for more info. 

Here are a few queries to ask the staff of the Toronto municipality:

  • What kind of servicing does my home have, according to Toronto municipality?
  • How is Toronto municipality addressing flooding in the community?
  • What steps can I take as a homeowner in Toronto to safeguard myself and my neighbors?
  • Where can I obtain additional information on basement flooding from Toronto municipality?
  • Does the Toronto municipality have any financial assistance programs available?

Contact a Plumber for a Plumbing Inspection

To minimize the risk of basement flooding, it’s important to have a good understanding of how your home’s drainage and plumbing systems operate. Due to the evolving building practices and codes, each home is unique. There are certain aspects of your plumbing system that are helpful to be aware of, such as:

  • Where is your sanitary sewer lateral located? Are there any trees located above it?
  • Does your home have a storm sewer lateral? If yes, where does it drain to?
  • Do you have a backwater sanitary valve installed on your lateral, and do you know how to maintain it?
  • How does your foundation drainage system function? Is it connected to the sanitary sewer?
  • Do you have a sump pump and sump pit, and if so, where do they discharge the water?
  • Where do your downspouts lead to, and are they emptying into the sanitary sewer?

To comprehend these elements of your home’s plumbing, it may be advisable to consult with a licensed plumber who can perform specialized testing or inspection, including the use of video cameras.

Determining how the foundation drainage works and where it drains to can be challenging, and a video inspection may not always suffice. Obtaining information about your home’s plumbing may necessitate additional efforts, such as engaging specialized contractors who can conduct camera inspections or dye testing.

plumbing inspection for basement flooding prevention

Insurance Coverage for Basement Flooding

In Canada, flood damage related to “overland flooding,” which includes flooding resulting from heavy rainfall, riverine flooding, and all other types of overland flooding, is not covered by insurance. This also includes flooding that occurs as a result of foundation cracks or sump failures.

However, standard home insurance policies do provide coverage for sewer backup, whether it’s caused by the storm or sanitary sewer system.  

It’s important to note that this coverage isn’t always automatic, so it’s advisable to confirm with your insurer that you’re covered for sewage backups and to review the terms of the coverage. For instance, what would happen to your coverage if you make a claim? How would it impact your premiums or insurability? Understanding this aspect of your coverage will help you comprehend the implications and determine what is covered and what isn’t. If your home is uninsurable due to previous flood claims, it’s worthwhile to inquire about how to reinstate coverage, if possible.

As a Homeowner, You Have Responsibilities for Preventing Basement Flooding

It is the homeowner’s responsibility to manage their connections to the municipal systems and the materials they deposit into them.

Here are a few key items that homeowners should be aware of and comprehend:

  • Ownership of the sewer lateral is shared, with the municipality being responsible for the section from the property line to the sewer main, while the homeowner is responsible for the portion on their private property, usually from the property line to the home. This responsibility includes maintaining and preserving the connecting pipe.
  • It’s essential to note that only sanitary sewage is allowed to be discharged to the sewer, which means that connections from roof leaders, sump pumps, and weeping tiles are considered illegal connections. Not only do these connections raise your risk of flooding, but they also raise the risk of flooding for your neighbors and increase the likelihood of sewage bypassing into the environment.

Never Pour Oils and Grease Down the Drain

To prevent sewage backups, it’s crucial to avoid pouring fats, oils, and grease down the drain. These substances have a tendency to solidify and accumulate in your internal plumbing, the sanitary lateral, or the sewer main. Although fats, oils, and grease may be in liquid form when warm, they solidify rapidly as they move through the plumbing network. Flushing them down with hot water typically doesn’t eliminate the risk; it may just push the substances further down the plumbing system.

It’s important to note that the municipality will not be responsible for any blockages caused by fat, oil, or grease accumulation found on any portion of the lateral.

do not poor oils and grease down the drain

You Can Minimize Household Water Usage During Heavy Rainfall

While rainy days may provide an opportunity to tackle domestic chores such as laundry and dishwashing, such activities can increase flood risks for both you and your neighbors. To reduce the risk and alleviate pressure on the sewer system, it is advisable to wait a few hours after heavy rainfall before engaging in water-intensive activities in your home. This can benefit you and your neighbors alike.

This is particularly crucial if you have a backwater sanitary valve installed on your sanitary sewer. In the event that the valve is closed due to a full sewer, your domestic wastewater will not be able to drain to the main sewer, potentially resulting in flooding of your home.

Avoid Storing Items On Your Basement Floor

It is advisable to avoid storing items on your basement floor as it is the area in your home that is most susceptible to flooding. Since water accumulates on the basement floor first, any items stored there are at high risk of getting damaged. However, if you must store items on the floor, it is recommended that you elevate them on shelves or supports or store them in water-tight containers to minimize the risk of damage in case of a flood.

It is Better Not to Invest Alot In Basement Living Space

Over the last decade, there has been a significant change in the way homes are used, with an increasing reliance on basements as livable spaces. Basements are now commonly finished and utilized for high-value purposes, such as recreation rooms or gaming rooms, equipped with costly electronics and exercise equipment. This shift has led to a consistent and significant increase in the average value of flood-related claims in the insurance industry, ranging from $15,000 to $20,000 per claim, with some claims reaching as high as $50,000 to $100,000.

This trend suggests that homeowners may either be unaware of the risk or knowingly choose to accept the risk in order to make use of the basement space. It is important to note that despite following recommended measures, such as lateral sewer maintenance, the risk of flooding cannot be completely eliminated. All basements are at risk of flooding, and it is important to consider this when planning how to use the space. It is also worth noting that even with regular maintenance, all roofs and driveways will eventually deteriorate, and sewer laterals may fail, leading to potential water damage.

basement living space after flood

You Should Keep the Nnearest Catch Basins Clear

Storm sewer grates, known as catch basins, are located on the streets and are responsible for draining storm runoff to the storm sewer system. Some properties may also have catch basins in their front or back yards. During the spring melt or fall season, catch basin grates can accumulate debris, leading to blockages. This can result in localized street flooding, which may increase the risk of high groundwater levels and surface flooding in nearby areas, including homes. Unfortunately, insurance does not cover such incidents. To prevent these issues, it is recommended that you take responsibility for any catch basin outside your home or on your lawn, or even your neighbor’s lawn, by keeping it clear of debris. This simple act can save you or your neighbor from flood-related problems.

The City of Toronto is responsible for catch basin maintenance, but during certain times of the year, it may be challenging for them to maintain all catch basins simultaneously. Therefore, if you notice a catch basin near you and are willing and able, it would be beneficial for both you and your neighbors to clear any debris, such as leaves, from it.

Seal the Cracks in Your Basement Walls and Home Floors to Avoid Basement Flooding

As previously mentioned, while some insurers may provide it as additional coverage to your home insurance policy, in most instances, home insurance does not include protection against floods caused by surface or groundwater infiltrating your basement, whether through direct overland pathways or cracks and gaps in your foundation walls or floor.

As with any structure, foundations undergo wear and tear over time. As a result of this wear and tear, along with potential construction defects and differential settling, cracks may emerge in your foundation, either on the walls or on the floor. When the groundwater level surrounding your home rises, it may inundate these cracks and apply pressure to them, causing them to leak water. Leakage rates may range from minimal to significant, depending on the volume of water present near the crack and its size. Therefore, it is crucial to maintain your foundation, just as you replace your roof shingles every 10-15 years.

In numerous instances, you may be able to simply seal the cracks from inside the basement without the need for excavation. However, for more significant or persistent cracks, you may need to engage the services of professionals, as they may require more substantial repairs to be done on the exterior of the house.

You can search through yellowpages.ca for professional foundation repairs.

Eliminate Overland Flow Routes

Insurance policies do not cover the flooding caused by the entry of water through overland flow paths. Overland flow paths are any route that allows surface water to enter, and there are several potential paths. These paths may include service holes in the basement intended for incoming electrical mains or natural gas to power a furnace, among other things. Other routes may include gaps beneath doors or leakage around aging window frames or window wells.

Homeowners should take appropriate measures to seal all potential overland flow routes and, ideally, redirect the water source at those locations elsewhere through proper site grading. It’s worth noting that reverse slope driveways and window wells are examples of overland flow paths that will be further examined later on.

It’s Important to Keep Your Eavestroughs and Downspouts in Dood Condition

To guarantee proper drainage of rainwater from your roof, it’s advisable to maintain your eavestroughs and downspouts. This entails ensuring that they are free from any debris and not partially or fully blocked. When eavestroughs and downspouts are clogged, water can accumulate and overflow, discharging close to the foundation. Additionally, blockages can cause water to freeze and expand, breaking the seam on downspouts and causing water to spill down the wall and create basement flooding.

It’s recommended to take a stroll around your home during heavy rainfall to verify that everything is functioning correctly.

Considerations for Your Downspouts

When it comes to downspout discharge, it is best to aim for a location as far away from the foundation as possible or at least two meters away from a permeable surface such as a garden or lawn. However, there are a few factors to keep in mind:

Firstly, ensure that the water does not flow onto your neighbor’s property, as this could create additional flood risk and is illegal.

Secondly, avoid discharging onto a sidewalk or walkway, as it can create a slip hazard. In some cases, exemptions may be available.

Lastly, adding a two-meter extension to the downspout can create a tripping hazard or obstruction. In such cases, a swiveling or folding downspout extension may be a better option, allowing you to fold it up and out of the way while mowing the lawn or hosting events.

Control Surface Water Around Your Home (Highly Efficient)

In order to promote proper drainage of water away from your home, it is generally recommended to slope the ground and surface features away from the foundation. This is typically required by code for new homes, known as “positive lot grading.” However, with older homes, settling, landscaping changes, and new additions or decks may cause positive lot grading to deteriorate over time.

If lot grading is neglected, it may result in water moving toward the house, increasing the risk of flooding. To prevent this, it is important to ensure that grading directs water towards a swale or natural drainage path so that it does not pool. Additionally, it is important to consider the impact on neighboring properties and not worsen their drainage issues or increase flood risk.

Swales, or ditches, are important features on a property that help move collected water efficiently to discharge points such as catch basins or creeks. It is important to be aware of these features and not obstruct the flow of water by constructing fences or sheds that impede runoff. This reduces their effectiveness in preventing the pooling of water.

Private-side catch basins may also be installed to prevent persistent pooling of water in specific locations, such as in rear yards. Homeowners can consider speaking with the City Engineering Department about installing catch basins if there is a suitable outlet nearby, although this may come at a cost.

During construction, the excavated area around the home’s foundation is backfilled with disturbed soil that is not as compact as the undisturbed soil. This may create a preferential flow or drainage path for water near the foundation and reduce grading over time, potentially reversing the flow toward the home. Settled backfill areas should be filled and graded away from home, with a less permeable surface to promote flow away from the foundation and reduce infiltration.

Surface Water Around Home

Control Ground Water Around Your Foundation

Having a functional and efficient foundation drainage system is crucial for keeping your basement dry. However, the type of drainage system can vary depending on the age of the home and the neighborhood it is located in. Older homes built before the mid-1900s may not have any foundation drainage system, making it difficult to determine without a plumbing inspection.

For homes with a foundation drainage system, there are typically several components to it. Coarse gravel is used around the foundation floor and outside the foundation walls to allow for quick water drainage. A weeping tile, which is a perforated drain pipe, collects the water and directs it to a suitable drainage destination. If there is a sump pit, it is likely that there is also a weeping tile that collects water around the foundation and directs it to the sump pit. Sump pits can either be perpetually dry or wet, with pumps that run 24/7. If there is no sump pit, the weeping tile may simply direct water away from the home to infiltrate into drainage materials or be connected to the sanitary or storm lateral.

Weeping tile system

Having a functioning weeping tile system is crucial for keeping a basement dry and usable. If you are experiencing basement dampness, wetness, or recurring flooding and do not have a foundation drain, it may be worth considering having a weeping tile installed. However, it is important to note that weeping tile systems, like sewer laterals, require maintenance over time. As the pipe ages, it may become clogged with sediments or collapse, which can lead to increased dampness or flooding in the basement.

To maintain the weeping tile system, built-up sediments can sometimes be flushed out without excavating the pipe. However, if the pipe is collapsing or has deficiencies, a full replacement may be necessary. During replacement, additional access points can be installed to facilitate future flushing and inspection of the system without excavation.

It used to be common practice to let a foundation drain go directly to the sanitary sewer lateral, which can contribute to basement backups and bypass the environment. To reduce this risk, it is recommended to disconnect the weeping tile from the sanitary sewer and install a sump pit and sump pump(s). Additionally, promoting the flow of water away from the foundation through downspouts and surface drainage can reduce the dependency on a sump system during rainfall.

Sump pit and pumps

To maintain effective foundation drainage and minimize risk, it’s important that any groundwater collected by the weeping tile around your home is directed to the sump pit and pumped away from the house using one or more sump pumps. This approach separates your home’s foundation drainage from both the sanitary and storm sewer systems. To comply with the law, it’s crucial that the outlet pipe from the sump pump doesn’t discharge into the sanitary sewer system. Instead, it’s best to direct the water to the lawn, allowing it to infiltrate naturally into the ground.

To avoid adverse effects on neighboring properties or public areas, the discharge location should be at least 2.0 meters away from the foundation. It’s also essential to ensure that the chosen location doesn’t pose a health and safety risk to your property, a neighbor’s property, or a public sidewalk or road. For instance, the water discharge should not create hazards like freezing on a driveway or a public sidewalk during the winter. Remember, this water is your own stormwater runoff, and you are responsible for accommodating it on your property.

Three critical factors are required for your sump pump system to function effectively when you need it:

  1. Proper sizing: The number of sump pumps or rated power depends on the dampness of your foundation. The installation contractor should be able to help determine this. Sometimes two smaller pumps are preferable to one larger one, as they can back each other up.
  2. Maintenance: Failing to maintain your sump pumps may result in them failing when you most need them. Consider creating a regular maintenance schedule and occasionally testing the pumps. Follow the manufacturer’s recommendations.
  3. Backup power: Most sump pumps operate on electricity and will not work during a power outage. For backup purposes, consider providing backup power to a second pump, whether by battery or generator.

Backwater Valves

A backwater sanitary valve is a device that typically allows water to flow in one direction, blocking reverse flow by shutting off when water levels rise downstream. These valves can provide some protection against sewage backups when incorporated into sewer laterals.

Proper installation and choice of valve type are essential factors, and the following points should be considered:

  • A backwater sanitary valve installed on the sanitary lateral must be “normally open” to allow for proper ventilation and failure in the open position.
  • The valve must be installed according to the manufacturer’s instructions for placement and grading.
  • The valve’s location relative to other sewer lateral connections, such as plumbing fixtures and foundation drainage, is critical.
  • Maintenance is necessary for the valve to function correctly.
  • Awareness is essential as the valve’s closure during rainfall or before water usage increases the risk of flooding.

Despite the challenges, a well-installed and well-maintained backwater sanitary valve can provide increased protection against sewage backup.

To install a backwater sanitary valve, a plumbing permit is required, and a licensed plumber must complete the work.

Read more about backflow preventers.

Maintenance of Sewer Lateral

The pipe that connects your home’s internal plumbing to the sewer main in the street is known as the sewer lateral, and it is an essential part of the system. Any blockages or failures in this pipe can result in sewage backup within your home.

It is important to regularly maintain your sewer lateral, especially if your home is older. Inspection is the best way to detect and address potential problems before they escalate and cause a sewage backup. It’s not just failures that pose a problem; a cracked or leaky lateral that permits groundwater infiltration can also increase the risk of flooding.

To avail of this service, contact a professional plumber who can assist you.

Storm Sewer Lateral

Storm Sewer Lateral

Although a storm sewer lateral can be a convenient outlet for storm and groundwater, it also serves as an additional connection to the municipal storm sewer system. Unlike the sanitary sewer, the storm sewer is designed to be full and surcharge every 2-5 years on average. While it may be useful for downspout and foundation drainage, it can also pose a liability when it overflows.

If you are not utilizing the storm lateral, it may be beneficial to have it disconnected near the property line. This means that you should direct your downspouts and foundation drainage to the surface of your lot to allow for the infiltration of groundwater and avoid excess water on your property.

The severance of the storm lateral will require a permit and the assistance of a contractor to complete the work.

Reverse-Slope Driveways

To clarify, the reverse-slope driveway slopes downhill toward the home rather than toward the road. This can create a significant flood risk, as water from the road can flow down the driveway toward the house, particularly during heavy rainfall or snowmelt.

Typically, the road is part of the “major” storm drainage system, designed to provide drainage of storm runoff when the pipe system is full every 2-5 years. Catch basins or drainage grates are usually installed outside the garage door to capture any runoff, but during heavy rainfall or flooding, they may not have enough capacity to handle all the water, leading to surface flooding of the home.

Here are some considerations to reduce the risk of flooding from a reverse-slope driveway:

  • Ensure catch basins servicing reverse-sloped driveways are connected to the storm sewer, not the sanitary sewer.
  • Consider building a small rise, around 15 cm or more, between the road and the driveway to prevent road runoff from flowing down the driveway.
  • Installing a backwater sanitary valve on the connection to the catch basin can reduce the chances of flooding.
  • Altering the drainage of a reverse-sloped driveway can be expensive, but it can significantly reduce the risk of flooding.

Keep in mind that altering the drainage of a reverse-sloped driveway requires considerable work and expense. It is also important to ensure that catch basins are well-maintained and regularly cleaned to prevent blockages and reduce the risk of flooding.

Basement Window Wells and Covers

The home’s moisture protection can often be compromised by basement windows, which is why window wells can be a helpful addition. They can enhance drainage around the windows to extend their lifespan and divert water toward the foundation drainage system instead of seeping through the framing or window.

To ensure better protection, it’s recommended to install window wells for all windows that are near or below the surface of the lot. The installation process should also include a drainage layer that connects to the weeping tile. Proper grading around the window wells is crucial, and it’s also advisable to install covers for window wells that are more prone to flooding.