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Trees near hydro lines in Cambridge: what GrandBridge Energy trims and what is yours to deal with

In Cambridge, GrandBridge Energy trims trees around its own lines in public spaces and along the low-voltage lines that run to buildings, and it will send a crew to assess and trim a tree on your property that is growing into a power line. If the tree has to come out altogether, that is the property owner's job to arrange and pay for. Nobody but the utility or a qualified contractor should be within 3 metres (10 feet) of a line, and no tree service we book cuts a tree that is in contact with one.

Last updated October 24, 2026 · Reviewed by the Cambridge Tree Removal team

Who is responsible for trimming trees near power lines in Cambridge?

It depends on where the tree is and what it is touching. GrandBridge Energy, the electricity distributor for Cambridge, says it routinely trims trees in public spaces and along the low-voltage power lines connecting to customer buildings. Its outdoor safety page is also direct about the other side: you are responsible for keeping trees trimmed on your property, that trimming should be done by a qualified contractor, and tree trimming and planting must meet Electrical Safety Authority standards. Where a tree on your property has branches growing close to a line, GrandBridge encourages you to contact it; its crews can assess the situation and trim vegetation as needed to keep the required clearance. If the tree must be removed, the property owner is responsible for arranging and covering the cost of tree removal.

So the division is roughly: the utility keeps its wires clear and will cut back what threatens them, the owner deals with the tree as a tree. In the older streets of Galt, Preston and Hespeler, where century maples and spruce grow through the lines on both sides of the road, that distinction comes up on nearly every removal.

The 3-metre rule

GrandBridge's rule, which matches the Electrical Safety Authority's, is to keep your body and equipment at least 3 metres from overhead lines. The utility's own example of when that matters is standing on a ladder, trimming trees or cleaning eaves. You do not have to touch a line to be shocked; electricity can arc to a pole saw, a ladder or a wet branch that gets too close. Pole-mounted transformers are treated the same way as an overhead line, with a 3-metre clearance. A downed line gets 10 metres, roughly the length of a school bus, and the ESA says to call 911 and the local distributor, which in Cambridge is GrandBridge at 1-877-871-2215.

For a homeowner, the practical meaning is that any branch within about 3 metres of a wire is off limits to you, your ladder and your saw, and that a tree with a line running through its crown is not a weekend project under any circumstances. For a tree service, it means the job is planned with the utility rather than around it.

Primary lines, the service wire and the transformer

Three different pieces of equipment turn up in Cambridge yards, and they are handled differently:

• Primary distribution lines. The high-voltage wires along the street and down rear-lot easements. Only the utility or utility-qualified line-clearing crews work near these. A tree service that is not qualified for that work keeps its people and rigging well clear and asks GrandBridge to trim or make safe first.
• The service wire. The low-voltage line from the pole to your house. GrandBridge says it trims along these lines, and that lines under 750 volts can be temporarily covered on request. The utility also offers a temporary disconnection before work near lines, free of charge during business hours. A removal of a maple over the drive with the service wire running through it is usually scheduled around a cover or a disconnect.
• Pad-mounted transformers. The green metal boxes at ground level. Keep 3 metres from them when working, and do not plant or build close to them so crews can get access.

How to get GrandBridge to look at a tree

The utility has a Request a Site Visit / Report a Concern form on its website, and one of the request options is a tree or branches entangled or leaning on power lines. Submit the form with the address and a description, and crews will investigate. For anything urgent, a branch arcing on a line, a wire pulled low by a limb, or a tree that has brought a line down, phone 1-877-871-2215, and for a downed line call 911 first and stay back 10 metres. The utility will clear what threatens its equipment. It will not take down the rest of the tree, grind the stump or haul the wood, which is where the tree service comes in once the line is safe.

Time it sensibly. If you know a tree has to come down and a line runs through it, the utility visit comes first, then the removal is booked. Asking the tree service to "just work around it" is asking them to break the 3-metre rule.

Does the City's tree by-law still apply?

Yes, for the tree itself. Cambridge's Private Tree Preservation By-law 23-105 exempts work done by an electricity distributor on its distribution system, so GrandBridge trimming a tree back from its line does not need a City permit. The owner removing the tree afterwards is a different matter: a private tree of 20 cm or more in diameter at breast height still needs a permit or one of the exemption routes, dead tree, imminent hazard or emergency, through forestry@cambridge.ca. A tree that has been trimmed hard on one side by line clearing and is now lopsided over the house is often a legitimate hazard submission, and the arborist report says so. The City's forestry page also notes that the City may prune private trees that conflict with City infrastructure, limited to hazardous branches and standard clearances, with notice to the owner. Trees in the boulevard between the sidewalk and the curb are the City's and are reported to Service Cambridge at 519-623-1340, not to the tree service.

When to call a pro

Any tree with a wire in or near its crown, any branch within 3 metres of a line, and any tree over the service wire to the house is professional work with the utility involved. The contractor we book for Cambridge checks for lines on the site visit, calls GrandBridge where the clearance cannot be kept, schedules a cover or disconnect where the service wire is in the way, and keeps the climber, the rigging and the crane outside the clearance on the day. Our pruning and crown reduction page covers clearance pruning on trees that are staying, and the cost page explains how wires change the method rather than just the price. If you are not sure whether a line is a problem, send a photo that shows the tree and the wire together.

Sources

• Outdoor electrical safety - GrandBridge Energy
• Request a site visit / report a concern (trees on power lines) - GrandBridge Energy
• ESA reminds Ontarians to keep a safe distance from powerlines - Electrical Safety Authority
• Forestry (city trees, hydro line trees, By-law 23-105) - City of Cambridge
• Private Tree Preservation By-law 23-105 (full text) - City of Cambridge