Thunder Bay Hydro's Tree Trimming Program
- Why Does Thunder Bay Hydro Trim Trees?
- What Does the Law Say?
- Responsibility & Qualifications
- Who Cleans What? What about Storm Damage?
- Why not just Lop the Top Off Trees?
- What to consider When Planting a New Tree
- Questions and Contacts
Why Does Thunder Bay Hydro Trim Trees?
Thunder Bay Hydro has an aggressive tree trimming program that maintains and removes trees and limbs along utility easements to prevent contact with high voltage electrical wires. The purpose of the program is to ensure public safety and to provide a reliable electrical service to all of our customers by preventing unscheduled power interruptions.
Safety
Anyone who prunes or climbs trees that are in contact with the power lines is putting themselves into potentially highly dangerous situations.
Trees and the ground around them may become energized when branches come into contact with the power lines.
Momentary contact between the tree and energized power lines could be fatal to anyone who is in proximity of the tree.
Reliability
Trees are a significant cause of power outages. Outages from trees are caused from branches rubbing on power lines, branches falling on power lines and trees falling across power lines during storms.
By trimming power lines on a regular schedule to a minimum clearance, Thunder Bay Hydro will eliminate predictable safety hazards and reduce tree related outages.
Legislation
The 1998, Electricity Act of Ontario requires that Thunder Bay Hydro maintain trees and brush to minimum clearances around its power lines. Ontario’s Occupational Health and Safety Act and Regulations stipulate what those clearances are and what the “Safe Limits of Approach” are for trained and untrained persons.
Utilities' Access to Private Property
The Electricity Act grants access for Thunder Bay Hydro to “enter and maintain any land for the purpose of cutting down or removing trees, branches or other obstructions”.
Easements are established at the municipal development planning stage that allows Thunder Bay Hydro and other utilities to access and maintain equipment on private properties. In addition, homeowners and private businesses are required to sign a “Terms of Agreement” with Thunder Bay Hydro that agrees to allow access for maintenance before service connections are made.
Responsibilities and Qualifications
Minimum clearances are required between power lines and trees, branches and foliage. Homeowners are responsible to keep trees clear of the service line that runs into their homes.
Thunder Bay Hydro has the responsibility and the training to trim or remove trees inside of the power line corridor.
Limitation
Thunder Bay Hydro will only remove trees outside of the power corridor when these trees could fall into the line and create a hazard.
Staff Qualifications
Thunder Bay Hydro uses highly skilled and specially trained staff and contractors to conduct any work inside the power corridor. Trees are trimmed to International Society of Arboriculture and the ANSI A300 Standards. These are also the standards that the City of Thunder Bay follows for tree work.
Tree trimming crews have the latitude to make site by site decisions regarding trimming of trees to maintain safety and aesthetics while achieving appropriate system clearances
Who Does What?
When a Thunder Bay Hydro crew or an approved contractor is conducting tree trimming or line clearing during regular maintenance, limbs, branches and other debris will normally be removed from the property.
In the event of a removal of a tree, larger pieces will be cut into manageable lengths and left for the homeowners use or disposal.
When a homeowner is contracting a private tree service to trim or remove a tree, Thunder Bay Hydro will assist in making the tree safe for the contractor to conduct their work or will provide a temporary outage to allow the contractor to remove or trim the tree safely.
Storm Damage
When trees and branches are cleared from power lines due to storm damage, emergency crews will not clean up the debris but will leave it for disposal by the property owner.
Why Not Just Lop off the Top?
Topping was a practice conducted by tree workers in the past who did not understand the art and science of tree care.
Thunder Bay Hydro crews are highly trained and skilled and will not top trees.Topping creates poor tree form that is weaker and more susceptible to disease and wind damage. Topping causes stress to the tree by significantly reducing the trees ability to produce food.The tree reacts by activating dormant multiple buds that create poorly attached branches that require more frequent pruning.
This will eventually lead to further conflicts between the tree and the power lines.
Tree Replacement and Planting New Trees
Homeowners can avoid service interruptions, help reduce costs and maintain a pleasant environment by ensuring trees of the correct size and species are planted near power lines. Do not plant trees that will grow tall near electric power lines, chose only low growing compact species.
Thunder Bay Hydro will not replace trees that have been removed due to poor selection of planting location.
Easements are granted at the time of development to allow access for utility companies. For properties that contain utility easements, Thunder Bay Hydro requests that homeowners not plant trees or otherwise encroach on easements in a manner that will limit access or interfere with operation of the lines.
To Ask Questions or Make Contact
To report a concern about trees and power lines, please call Thunder Bay Hydro Power Systems Division at 343-1176.
To request the temporary disconnection of a line from your private residence to the main corridor in order to conduct tree trimming on your private property, call 343-1176.
To report a concern regarding boulevard trees, please contact The City of Thunder Bay, Parks Division at 625-2351.
For more information regarding trees and utilities or tree questions in general, the International Society of Arboriculture webpage provides an excellent source of information on all tree topics.
This page last updated 2013-03-14.





