FAQ - Vegetation Management

Powerlines and Your Trees – Keeping It Safe for Everyone

Why must trees be pruned around powerlines?

To provide safe and reliable service to all of our customers, Oakville Hydro must prune trees near the powerlines. As well, we are legally required through the Electrical Safety Authority of Ontario and the Ontario Electricity Act to prune trees and plants growing near powerlines.

With time, trees can grow into, fall onto or have their branches break off over powerlines during storms. When this happens, the electricity service to your home, your neighbours’ homes and whole communities can be affected. There are a range of potential disruptions – everything from flickering lights to a complete loss of power.

Since powerlines are interconnected, damage can be felt at many points across the electricity grid. In the worst case, a tree can take down an entire line and break the poles that hold the line in place.

As well, there are many safety issues arising from trees being too close to powerlines:

  • Powerlines knocked down by trees may still be energized and are very dangerous if approached or touched. Serious injuries or death can occur if the tree or energized powerlines are touched.
  • People can climb trees and, by mistake, touch an energized powerline. Touching a powerline is dangerous no matter if you are on the ground or up in a tree.
  • People standing near a tree that is touching a powerline can be electrocuted as the power always goes to the ground.
  • Trees can obscure a work area and make it dangerous for people doing maintenance on a powerline or trying to keep the trees in the area pruned.
Who is responsible for pruning trees around powerlines?

Oakville Hydro contracts the Town of Oakville’s Forestry section to carry out regularly scheduled tree maintenance on our behalf. To keep to pruning schedules or deal with special situations, the Town of Oakville may need to contract private, specialized tree experts to assist. These private contractors prune trees with the same care as the town’s Forestry Services. There are 18,000 municipal and privately owned trees in the town’s hydro line clearing program.

Property owners are responsible for having their private trees and other vegetation such as vines properly maintained around powerlines. Please contact a certified tree contractor for more information about their services, including cost. It’s important to be mindful of the location of the powerlines before you start pruning. Safety regulations require anyone working or lifting within three metres of overhead powerlines or poles to contact their local electrical distribution company for assistance. In Oakville, that’s Oakville Hydro. Serious injury, even death, can result if you come into contact with a powerline during routine tree maintenance. We can create a safe work environment for you or your contractor to prune trees, or for your electrician to access powerlines. Call us at 905-825-9400, ext. 5274. Within one week, we will come out and assess the situation.

During hydro line clearing, service contractors, using sound judgement, will prune private trees when necessary or will advise the property owner to have the necessary work done. The Electricity Act grants access for Oakville Hydro and its contractors 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 Oakville Hydro and other utilities to access and maintain equipment on private properties.

Please note: Ownership of a tree is determined by the actual physical location of the tree. Whoever is the owner of the land upon which a tree is situated is also the owner of that tree. With that ownership comes all the corresponding responsibility for the care and maintenance of the tree. It does not matter who actually planted the tree – the owner of the land upon which the tree is located owns the tree and is responsible for that tree.

How much will be pruned from the trees?

Each tree is different and is considered individually. We look at:

Species growth habits (rate, size, shape, etc.)
A tree’s position in relation to the power line (including how close the trunk is to the powerline)
Its current condition, including individual branches
Whether the tree is deciduous or evergreen (each requires different pruning techniques)

As well, different power lines (high voltage primary lines and low voltage secondary service lines) have different clearance requirements. Our arborists make every attempt to obtain sufficient clearance so that the tree will remain safe until we return on our next maintenance cycle.

The current Electrical Safety Authority’s (ESA) industry standard is a clearance of three metres (10 feet) from primary lines.

How often does Oakville Hydro prune trees in my area?

We employ a systematic approach to maintaining our overhead high voltage and low voltage secondary lines in Oakville. The condition of vegetation (trees and plants) around the powerlines dictates our need to manage the growth. Depending on the conditions on a given line, our maintenance schedule is to cover the whole Town of Oakville every four years.

Will I be notified before a tree crew comes to cut trees on my property?

Yearly pruning usually starts in January of every year and lasts until late May. We prune all the trees within one area of town every four years.

Prior to the program starting:

  • Notices are sent to local media.
  • Advertisements will run in the community newspaper.
  • A letter will be mailed to all residents in the affected area.
  • Notice may be left at your door if a significant amount of pruning or tree removal is necessary.
  • Information is posted on Oakville Hydro's website and the Town of Oakville’s website.
  • A public open house will take place.
Is Oakville Hydro responsible for cleaning up after pruning trees around distribution lines?

The majority of our pruning occurs during line maintenance cycles. In the Town of Oakville, our policy is to dispose of any small branches and brush. The larger pieces of wood are normally disposed of along with everything else. In non-maintained sites, pruned vegetation and wood is left in place. These materials will bio-degrade into their natural components.

What if my tree is unsafe?

When trees are on private property and are dead or unhealthy, the tree is not only a danger to you, your property and the general public; it is also a danger to Oakville Hydro’s powerlines.

If you come upon a situation in which you feel your tree is unsafe, please inform Oakville Hydro by calling 905-825-9400, ext. 5274 or emailing us at trees@oakvillehydro.com. One of our customer service representatives will be happy to assist you. You are required by law to have the tree(s) looked at and made safe. You must contact a certified arborist contractor and have any tree issues resolved. As property owner, you are responsible for all costs associated with the work done on the tree(s) on your property, including clean up.

Why are trees planted so close to powerlines in the first place?

The Town of Oakville plants trees on municipal property according to the right tree in the right place principle, taking site lines and proximity to powerlines into consideration. In some instances, trees are planted on municipal property without the town’s knowledge or consent.

Do the Town of Oakville’s arborists "round-over" and/or "shape" trees?

The Town of Oakville does not “round” trees over because it’s not good for the health of your trees. We subscribe to a method of pruning called lateral and directional pruning.

If your preferred certified tree contractor has a certified arborist on staff, ask them about healthy pruning techniques for your trees.

Are trees pruned or removed for the installation of new electric lines?

When we’re installing new lines, we evaluate the best routes to minimize the impact on the environment. Any route may involve removing trees. We try to balance tree preservation with proper pole and line installation and maintenance.

What should I do before planting trees and/or plants near pad-mounted transformers and distribution powerlines?

Please refer to Selecting a Tree with Power Lines in Mind before proceeding. It contains all of the details and information.

Who should I call if I’m worried about trees or plants growing near powerlines in Oakville?

If you have concerns about trees or vines growing near power lines, please contact us by calling 905-825-9400, ext. 5274 or emailing us at trees@oakvillehydro.com. One of our customer service representatives will be happy to assist you.

Who should I call if I see a powerline on the ground?

Please stay as far away as possible from any wire on the ground and call Oakville Hydro immediately at 905-825-9400 to notify us of the danger.  You should maintain a distance of 10 metres or more from a downed overhead powerline.

Who should I call for tree pruning around streetlights?

Public streetlights are owned by the Town of Oakville (with exceptions for some condominium corporations and mall parking lots). For tree maintenance around streetlights, please call ServiceOakville at 905-845-6601 and leave the exact address of the light in question.

Who should I call for clean up after storms and accidents?

When an act of nature (such as lightning, ice storms, snow storms, high winds, thunderstorms, tornadoes) or an accident causes your tree or vegetation to fall across power lines, creating a hazard or a power interruption, Oakville Hydro will cut and move enough of the trees and brush so poles and lines can be replaced and reenergized. The remainder of the cutting and disposal of all wood, limbs and debris resulting from this type of emergency operation is the responsibility of the property owner.

Any work done on trees in close proximity to hydro lines must be done by a certified tree contractor. Oakville Hydro will work with you and your chosen contractor to make the area safe prior to any work being completed. As property owner, you are responsible for all costs associated with the work done on the tree(s) on your property, including clean up.

Who should I call to locate underground utilities?

For assistance in locating and marking underground utility lines, contact Ontario One Call at least seven business days before you plan to start digging. You can call them at 1-800-400-2255 or visit www.on1call.com.