Property Drainage and Flood Prevention

Grading is the shaping and sloping of the lot to direct water from rainstorms, snowmelt and groundwater toward the stormwater management system. A properly sloped surface can greatly reduce the risk of water from entering your home. When you grade or landscape your lot, make sure there is a 5% slope away from the home for the first 1.5 metres.

The most important thing to keep in mind with grading is making sure that the water has somewhere to go. Often, changes made to the grade of the lot from landscaping or the construction of fences, sheds or decks can interfere with the path of rainwater as it moves toward the stormwater management system. These changes can cause water to collect in your yard or redirect back toward your house where the water may seep through the foundation walls, window wells and possibly into your sewer system.

Drainage swales are shallow sloped ditches that property owners can build to channel surface water to drain toward the stormwater management system.

Eavestrough and downspouts collect and channel rainwater away from your home and towards the stormwater management system. To ensure the water is not draining directly down the side of your foundation regularly check and clean your eavestrough and downspouts of debris and ice and attach an elbow fitting or splash pad underneath your downspout to channel the water away from your foundation. The downspout should be directed a minimum of 1.5 metres away from your foundation.

Downspouts that are connected to your sanitary sewer line are prohibited and can cause a sewer back up because the excess water is forced back through the pipes and into your home during a rainstorm. Disconnecting the downspout from the sewer system may cause surface flooding if the lot is not properly graded to drain water away from the home.

Weeping tile is a perforated pipe that collects and diverts groundwater and sub-surface water from around the exterior of your foundation. Ground water seeps into the perforated pipe and drains into a sump pit, rather than seeping into your foundation.

The weeping tile sold today is perforated plastic but some of the older homes may still have clay weeping tile which can breakdown over time causing a blockage in the line. Water will always follow the path of least resistance and may start to seep into your basement if there is a break in the clay weeping tile. Tree roots can also infiltrate the clay tile causing a blockage in the line.

It is recommended that all basements have a backwater valve as a preventative measure to protect your foundation and furnishings. A backwater valve is a one-way control valve that a property owner can install on a sewer service line. When water starts backing up into the sewer line the valve closes and prevents the water from backing up into your basement. It is recommended that you clean and test your backwater valve on a regular basis to make sure it is working properly.

It is recommended that all basements have a sump pump as a preventative measure to protect your foundation and furnishings. A sump pump is a small pump that the property owner can install in the lowest part of a basement or crawlspace (usually in a sump pit). The pit is set in the basement floor and collects water from the weeping tiles around the basement. The pump is activated by a float when the water reaches a certain level then the water is pumped to an outlet outside of your home.

During heavy rainstorms, conserving water in your home can help reduce the demand on the sewer system which can help reduce the risk of a sewer backup in your home.