Understanding the difference between sewer backups and flood coverage

This guide is part of our series on water damage and tenant insurance. 

If your home is damaged by water, tenant insurance can often kick in to help you financially. It’s typically oriented around a renter's personal belongings and day-to-day living situation, covering what happens inside the unit rather than the building around it.

However, coverage under a basic tenant policy isn't always uniform from one insurer to the next. And all types of water damage don’t necessarily come included by default, which can leave a gap between what a policy contains and what a tenant might assume they’re covered against. Sewer backup and overland water are two types of scenarios that often fall into that gap, and each tends to be treated somewhat differently.

In this guide, we’ll be discussing both. From how they differ, to their impact on your tenant insurance, here’s what you need to know. 

Sewer Backup Coverage

A sewer backup happens when water or waste reverses course inside a building's own drainage system – moving back up through a drain, toilet, or similar fixture rather than away from it.

This type of backup is often connected to a blocked municipal line, a storm drain overwhelmed by heavy rain, or a sump pump that isn't able to keep pace with the volume of water it's handling.

Because the water originates from within the plumbing system rather than from outside the building, this type of incident tends to be treated as a distinct category from water entering through the ground or exterior. 

Overland Water (Flood) Coverage

A flood is generally defined as water entering a property from the outside at ground level, rather than water escaping from an internal source like a burst pipe.

This category is typically framed around water making its way in from outside the structure altogether, rather than something originating within the building's own systems.

Overland water is often connected to torrential rainfall, rapid snowmelt, a nearby lake or river rising above its banks, or water pooling on a street and making its way toward a building's lower levels.

It's worth noting the related but separate concept of underground seepage. Water gradually working its way through foundation walls from below ground is often treated differently than surface water flowing in from above, even though both are sometimes grouped loosely under the idea of "flooding."

Understanding the different types of water coverage events

Still need a clearer understanding of the difference between these two types of water events? Here’s a side-by-side breakdown of what you should know. 

Most tenant insurance providers let you upgrade water coverage, which typically extends to situations like sewer backups, overflows, or seepage. These usually fall outside what a standard policy covers. Coverage details and limits vary by provider, so it's worth checking what is or isn’t included by default as part of a policy.

The information provided on this page is intended for general educational purposes only and does not constitute insurance advice, a recommendation, or an offer to sell insurance. Every individual's insurance needs are unique and depend on personal circumstances. We encourage you to consult with an independent licensed insurance broker in your province who can assess your specific situation and recommend appropriate coverage.