This page was created as a resource to homeowners to identify possible causes of basement flooding and suggest tools and prevention methods to remedy the causes of basement flooding and improve drainage conditions at their home. Please check out our basement flooding guide for additional information.

If you are a resident of The City of St. Thomas, you may qualify for the basement flooding grant program. If you are having a sewer back-up, you may qualify for our Rodding Rebate program.

There are a few different types of basement flooding:

  1. Infiltration flooding - when soil around your home becomes saturated or when the ground water level rises higher than your basement and/or your weeping tiles are not working or are non-existent, water will get into your basement through cracks in the foundation walls and floor.
  2. Overland flooding - when water flows overland it may enter basements through windows, doors, vents and other openings. This could be due to improper grading, exposed window wells, and extreme wet weather conditions that exceeds the capacity of overland routes or under ground pipes.
  3. Sewer backup flooding - extreme weather events can overwhelm the City's sewer system and result in flooding. When this happens the water level in the system rises above the normal design levels. This condition is referred to as a surcharge. Basement flooding can cause serious damage and create a health hazard if not addressed properly.

Basement Flood Protection
Flood Protection

Potential causes of flooding

A. Weeping tiles and downspouts connected to the sanitary sewer

Weeping tiles and downspouts connected to the sanitary sewer

B. Malfunctioning sump pump

Diagram of malfunctioning sump pump that can cause basement flooding

C. Surface Water

Diagram of abundance of surface water that can cause basement flooding

D. City Sanitary sewer pipe full

Diagram of a City sanitary sewer pipe that is can full which can cause basement flooding