You now know that a home's wastewater drainage system is closely connected to the public sewer system. There are a number of ways your home's basement could be flooded, either by runoff seepage or sewer backup.

In fact, your basement could be at risk because of short- or long-term abundant rainfall, or in the spring, from snowmelt.

The following are some of the main reasons for flooding in the basement of a home:

1. the absence, improper installation or malfunction of mandatory protection devices (check valves) installed on your building's sewer drainage system;
2. poor soil drainage, resulting in a large amount of runoff near foundation walls, putting an unnecessarily heavy strain on the foundation drain;
3. cracks in the foundation walls or in the basement floor slab, allowing for water seepage;
4. water from downspouts running directly into the foundation drain or too close to the foundation walls, putting an unnecessarily heavy strain on the foundation drain; and
5. too narrow a clearance between the bottom of a basement opening (door or window) and the ground level, contributing to the risk of runoff seepage into your basement.

Although your home is to certain degree subject to different sources of flooding that could cause damage to your basement and its contents, there are a number of safeguards you can install. These will go a long way towards protecting your belongings, and enhance your safety.

(Source: Ville de Sherbrooke)