Basement Flooding Class Environmental Assessment (EA) Study

Any improvements to the sewer and drainage system to be made within the City’s property such as parks, roads and sewer infrastructure.

Study Exclusions

Each homeowner is responsible for the operation and maintenance of drainage systems on private property, which includes:

  • lot grading
  • front and rear yard or driveway drainage and catchbasins
  • foundation drains
  • sump pumps and backwater valves
  • private tree roots and what you put down the drains (e.g. fats, oil, grease, etc.)
  • disconnecting downspouts (roof leader)

Study areas are determined by the underground drainage system (sewer pipes). Your house may be located in other study areas where Environmental Assessments have been completed or planned for future study.

The Environmental Assessment study is about locating where to improve drainage in the sewer system, thus upgrading infrastructure in the City’s (public) roadway.  Homeowners are encouraged to hire their own licensed plumbers to investigate private property issues. The City will inspect the sewer system on the public roadway.

Any improvements to the sewer and drainage/storage system to be made within the City’s property such as parks, roads and sewer infrastructure.

Each home owner is responsible for the operation and maintenance of drainage systems on private property, which includes:

  • lot grading
  • front and back yard or driveway drainage and catch basins
  • foundation drains
  • sump pumps and backwater valvs
  • private tree roots
  • what you pour down the drains e.g. fats, grease, etc.
  • disconnection downspouts

Cases such as backyard ponding, home owners are encouraged to speak with a landscaper or contractor to discuss drainage issues and options for their backyards.

All new housing developments must meet City standards to provide for sufficient stormwater drainage management before being approved.

For concerns on local developments, please call 3-1-1 or email at at any time to find out the local City Planner’s contact for more information.

Our street are designed to carry stormwater flows that exceed the capacity of the storm sewer. Temporary ponding on streets is expected during major rain storms.

Flooding issues could be the result of any upstream or downstream system overloaded capacity, bottlenecks and/or constraints. Upgrades are aimed at improving the overloaded system upstream or relieving the system downstream of the flooding location. These system upgrades will improve areas on adjacent streets and this is why works are not planned for every street.

Flooding can also be caused by private property issues (e.g. poor lot grading or drainage, clogged/blocked rear-yard catchbasins, cracks/leaks in your home foundation, basement walls or basement windows or door). In these cases,  sewer system upgrades would not resolve flooding on your property. These issues are the responsibility of the homeowner.

While it is not mandatory for you to report instances of flooding to the City, it is recommended. City staff will review the problem and attempt to determine the source(s) of the flooding and include solutions if found to be a system deficiency.

Same case with reporting blocked sewer grates on the road curb.

Remember to write down the “reference number” provided to you so you may refer back to the work order later to track the case. You are encouraged to call 311 anytime.

If you suspect illegal sewer connections or yards built to drain stormwater to your property, you can contact the City’s By-law Enforcement by calling 3-1-1 or email

Unfortunately, it is not as simple as making the pipers larger. The challenge in which the pipes, how big to make them, and how it will affect other residents. Other constraints can include space availability, conflicts with existing or proposed future infrastructure, basement elevations, pipe depth and environmental impacts. The variability in the amount of rainfall and how fast it falls is vast, that it is impractical to design a pipe system to capture it all. As well, City Council approved funding priority and availability is also a factor in implementing these sewer system upgrades.

From Study to Construction

  • Once an EA study is complete, the recommended basement flooding projects are sequenced into a five-year project list which is presented on an annual basis to City Council.
  • Projects are prioritized and scheduled to protect the greatest number of properties as soon as possible, within approved budgets and coordinated with other construction work — as per Council approved criteria.
  • The length and type of construction will vary depending on the type of projects being implemented.

Construction Project Prioritization

Not all recommended projects from the study will proceed immediately to the design and construction stage. Projects are prioritized for implementation based a City Council adopted $32,000 cost per benefitting property threshold. Projects with a cost less than $32,000 per property at the EA stage and preliminary design stage proceed to construction.

Projects that exceed the $32,000 cost per benefiting property threshold will not be included in the five-year Project List to undergo preliminary design. They will be moved into the State of Good Repair’s long term capital plan.

The implementation of Basement Flooding Protection Program (BFPP) projects includes three key steps:

  1. Preliminary design
  2. Detailed engineering design
  3. Construction