Flooding: Prevention and Protection

As May draws to a close, spring is in full swing and already, rain is becoming an issue here in Toronto. Our islands are again seeing Lake Ontario lap over sandbags and every rainstorm brings up the fear of the flooding of the year before. In 2018, extensive flooding hit North York and the waterfront, submerging Spadina streetcars and flooding basements. There were even incidents of individuals being trapped in elevators, necessitating rescue responses. Drivers became stuck in their cars at streets along the lakeshore and the city sat soggy for a very long night.

(Shlomi Amiga/The Canadian Press)

 In 2017 the Toronto Islands found itself largely underwater, closing it off for much of the summer season. The residents there are already seeing flooding again this year, as previously once-in-a-hundred-year water levels become commonplace. 

Climate change and urban sprawl has turned our city into a magnet for risky flooding conditions, and while there’s not much you can do in the face of an act of god, we’d like to provide some basic tips that we suggest any homeowner look into to protect against damage to your home.


Flood prevention begins at purchase. I’m sure basement upsets are the last thing on your mind when buying a new home, but be weary of deals that look a little too good and sellers that are a bit too motivated. Often the only option left for homeowners stuck in a frequently flooded area is to sell, and the hazards of inclement weather are not exactly going to be the first thing on their lips when trying to sell you the property.

We recommend checking out historical flooding data in the area before putting money down. You can check out the city’s map of areas at risk for flooding over here: https://trca.ca/conservation/flood-risk-management/flood-plain-map-viewer/

Most floods tend to centre around areas that were historically streams and rivers that got covered up by concrete as the city expanded, leaving nowhere for heavy rainfall to go besides our heavily taxed sewer system.

It can be said for many things, but if a deal looks too good to be true, it probably is.


Do you already have a home in a floodplain? Do you not, but are still concerned as the weather gets warmer and wetter? Here are some renovation tips to help protect your home against flooding and water damage.

First and most simple, make sure you seal any cracks found in foundation walls and basement floors. They don’t seem like much now, but combined with the pressure from outside water, they could become major problems later.

Keep eavestroughs and downspouts clear of leaves and debris. Spring cleaning is no fun, but keep up at it to give water an easy way to get off of your roof and into porous ground.


If your downspouts are connected to the sewer system, disconnect them. Overwhelmed sewer systems are how we end up being flooded with more than just water. Look into techniques for doing so as long as you aren’t disrupting you or your neighbours’ land. Having them empty just into the yard in general is fine, but it’s recommended to have them sit  at least 2 metres away from the edge of your home to avoid buildup around the foundation.

 It’s tough in the city, but if you have the luxury of a yard, increase the amount of green space around your home. Soil and greenery are the best options for absorbing water and keeping it from puddling up on concrete. We recommend a garden or grassy lawn over a stone patio. 

Try to keep your basement readied for flooding if the worst should happen. Finishing the floor with tile is a safe bet, and we recommend not storing family heirlooms or important paperwork in your most at-risk areas. Cleaning up after a natural disaster will always be miserable, but make it a bit easier on yourself if possible.

One of our biggest pieces of advice is also the most complex. Much of the damage caused by flooding is due to our sewers being connected to other general drainage around the city and home. When the storm sewer drains flood, so does our waste. You can prevent this from happening at least inside your own property by installing a backwater valve.

backwater valve.png

Mainline backwater valves allow sewage to flow out of your house but not back in when the system is overwhelmed by heavy rain. If you own a newer home, you likely already have one installed, but if you’re not sure or your home is older, be sure to check. If you find your home without, contact a licensed plumber to install one. Currently the city of Toronto offers a subsidy of up to 80% of the invoiced amount, up to a maximum $1,250 to help offset the cost of installing this vital piece of plumbing. For more details on this program, check here:   https://www.toronto.ca/services-payments/water-environment/managing-rain-melted-snow/basement-flooding/basement-flooding-protection-subsidy-program/

This subsidy also covers installing a sump pump, if you don’t already have one. Most homes do, but it’s also worth checking out. Sump pumps help keep the area around your foundation unburdened with built-up water. They can lose power during severe storms when they’re most needed, so consider looking into a generator for yours just in case. 

The final piece of advice we have is to triple check what types of flooding are covered by your insurance. Many insurance companies will stop allowing coverage to homes in that are frequently flooded, their deductible is very high, or they only pay out a relatively low amount compared to the cost of cleaning and repairing a severely damaged home. There is not often much you can do about these scenarios, we can only recommend knowing how things work in detail so you aren’t blindsided in the middle of an emergency.


We hope you are able to stay safe, no matter what the weather brings, and that these tips were helpful. Feel free to contact us with any questions, and we wish you a dry summer ahead!