Preparing for Heavy Rainfall

Heavy rainfall or snowmelt can cause localized flooding, sewer backups and drainage issues to properties and neighbourhoods.

Prepare for Wet Weather

It is important to be prepared for wet weather; here are some steps homeowners can take to reduce the likelihood of flooding:

Grade and landscape your lot

Grade and landscape to make sure there is a positive slope away from the wall for at least the first 1.5 m (5 feet). The ground should drop a minimum of 75 mm (3 inches) in this area. Use landscaping to disperse the water more evenly. Aerate your lawn, especially if it is hard and compacted; this will help water soak into the ground.

Check and clean your private drains

Clear drains such as driveway drains, area drains, gutters and downspouts before a rain event, and be sure to check them after the rain starts. While you may clear a grate or drain before an event, the rain may wash debris back over the grate, which could cause flooding. Water flows from downspouts should be directed at least 1.5 m from the basement wall. Seal any cracks between your house and concrete areas.

Make sure your backwater valve is working

Backwater valves (if applicable) are mechanical devices used in many homes to prevent backflow and reduce the risk of sewer backing up into basements. If your home is equipped with this device it is recommended that periodic inspections be made to ensure it is operational.

  1. Remove the cleanout plug on top of the device and do a visual inspection.
  2. Use a flashlight to see inside the device and inspect for debris build-up.
  3. Flush away any debris found and inspect the valve 'O' ring to ensure it does not need to be replaced and that the valve is sitting properly.
  4. Ensure the valve moves freely and moves up and down and reinstall the cleanout plug.

Check your sump pump

If applicable, check the pump by slow-pouring water into the sump tank. Watch for the "float" to rise and trigger the pump. Once the pump has started, the water level will quickly lower, and the float will shut off the pump. Have a sump pump backup (such as a battery backup) should you lose power during a heavy rainstorm. Ensure your sump pump discharge is directed away from the house and draining properly.

Reduce your water use

During times of heavy rain, conserving water in your home can help reduce the demand on the sewer system. This can help reduce sewer backups.


If you notice that drains in the public right of way are covered or clogged, you can contact Public Works to ask them to clear the grate.

Make sure your private laterals (sanitary and/or stormwater) are working properly and, if needed, have them inspected periodically.

Are you experiencing water issues?

If you are experiencing water issues, please contact Public Works during regular business hours at 780-459-1557. Residents can also contact our After Hours Water and Wastewater Emergency Contact number at 780-458-2020.


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Last edited: October 30, 2019