Property, Gardens & Trees

Lot Grading & Drainage

Poor lot grading can lead to:

  • inadequate surface drainage
  • ponding
  • flooding
  • basement dampness or settlement
  • insurance claims
  • conflict between owners of neighbouring properties

It is the home owner’s responsibility to maintain the grading of their property as approved by the City when the subdivision was built.   

Drainage problems often occur due to:

  • new landscaping features
  • construction of fences, patios, sheds, walkways, decks and swimming pools

When you do any landscaping or construction, you should not disrupt the lot grading. This prevents drainage pattern changes on your property.


Swales are shallow grassed drainage channels with gently sloping sides. They collect and direct stormwater away from the building foundation, towards the street or catch basin. They are typically located along property lines that separate lots. You should not fill in or block the swales, as this causes stormwater to collect and pond on your property, potentially resulting in flooding during heavy rain storms.

Rear yard catch basins

Rear yard catch basins are located at low points along rear property lines to send stormwater to the City's sewer system. Do not block your rear yard catch basin in a way that prevents rain water from entering and discharging to the sewer system.