Plant and Tree Safety

Alectra Utilities is committed to providing safe, reliable electrical services to the City of Mississauga. Our ability to do this can be affected by trees and other greenery located in close proximity to power lines and electrical equipment. Trees growing too close to power lines can create a public safety hazard as well as cause an interruption in electrical service.

Trees coming into contact with power lines can:

  • Cut off the power to your home or business;
  • Result in property damage and expensive insurance claims; and
  • Pose a serious risk of electrocution.

Trees and other greenery located on private property are the responsibility of the homeowner.

When planting a tree, consider the full size it will grow to at maturity. Avoid locations near overhead and underground power lines.

As trees grow, the homeowner must ensure that all electrical equipment remains free from any potential obstruction. One common area where this becomes a concern is when plants or trees grow near pad-mounted transformers.

Pad-mounted transformers, commonly known as green boxes, are key components in our electrical distribution system and Alectra Utilities relies on homeowners and local businesses to keep these boxes clear of any obstructions. They require a minimum clearance of 3 metres in front of the transformer and at least 1.5 metres on the sides in order for our crews to gain access to the electrical components for maintenance or emergency work.

Although trees growing on private property are the responsibility of the homeowner, we urge you to contact Alectra Utilities immediately if you are concerned that a tree is growing too close to electrical equipment.

Our trained experts can assess your situation to ensure that you are fully aware of the potential hazards and will provide advice on how to proceed safely.


Guideline Documents

Below are two documents provided on behalf of the Electrical Safety Authority ( These guidelines are in response to the number of reports associated with power line contact incidents as a result of working on greenery in close proximity to power lines and electrical equipment.

under-trees   trees

These guidelines provide information to support trade workers, maintenance workers and homeowners. If followed correctly, these guidelines can decrease the number of electrical incidents and help prevent future problems with electrical distribution.