We're in your community, looking for trees that might cause outages

Image of worker in aerial bucket removing hazard tree next to BC Hydro line
A certified utility arborist helps remove a large, multiple top hazard tree beside a distribution line on Vancouver Island. The tree was being cut, piece by piece, to eliminate the safety risk of working so close to the power line.

You may also be able to help our 'veg management' crew identify hazard trees

Some good news, and some bad news, about power outages in B.C.

First the bad news. Despite a series of wicked storms in the province, including that freak windstorm of last August 29, there are still thousands of trees that could fall on power lines and cause outages the next time a big wind arrives.

The good news? BC Hydro's vegetation management team will be checking neighbourhoods across B.C. this spring in search of trees that could fall on our power lines. With trees identified, contactors will be sent out to prune or remove them.

"After a big storm like we had last August, people are of the mind that we might actually cut (vegetation) budgets," says BC Hydro's Gregg Hallaway, who oversees vegetation management in the Lower Mainland. "People say things like 'If it was going to fall, it would have fallen in last week's storm.' But it doesn't work that way. It's not like the wind comes in and consistently touches down in every part of a city or region."

As an example, the biggest storm of 2006 hammered Stanley Park and toppled an estimated 1,000 trees in the park. Then it spared most of Vancouver before touching down again at Burnaby Mountain. Each storm behaves a bit differently, and it's impossible to accurately predict exactly which neighbourhoods will get hit hardest.

We're proactive in pruning or removing trees primarily because it's a directive of the British Columbia Utilities Commission that we work to improve safety around power lines. And secondarily, it's to ensure our system is as reliable as possible, even when big windstorms hit B.C.

'We assess the trees that can impact the power lines, whether it's on a municipal boulevard, someone's front yard or someone's back yard," says Hallaway. If it's tall enough to impact our system, it's our due diligence to look after it. That's what the B.C. Utilities Commission puts on us, the obligation to look after those trees."

If we want to remove a hazard tree that's on your property, we'll contact you first. Unless a tree is in imminent danger of falling, we need to consult with you and get your authorization before we get contractors to remove a tree in your yard.

 'Worst-performing circuits' get extra attention

When Hallaway's crew starts checking for what they classify as "hazard trees" this spring, they will zero in on some areas that have a recent history of tree-related outages.

"We'll go into every municipality at some point," says Hallaway. "We're looking for hazard trees that have to be pruned or removed – we're looking for the dead, dying and leaning trees. But we also use outage statistics to come up with what we call a 'worst-performing circuits' list, divided up into different categories. We start with the worst performing circuits, and we'll drive them from the substation to the end of the circuit, looking for the worst trees on that circuit."

Helping our cause are the people who call us, especially following a storm, to alert us to trees that may have been damaged, but which haven't fallen. Hallaway says some members of the public call to say they heard a "cracking" sound, or saw something that looked like damage. "I really encourage people to phone us if they've seen or heard something out there. We can really use the extra eyes and ears."

Hallaway extends that call for help to non-storm related issues, such as excavations at new housing developments. He has seen instances where contractors have tried to save some big trees but have excavated to one side of them enough to undermine the root system that would keep the trees standing in a big storm.

"I'd just say to the public, you're the best watchdogs for hazard trees on your property, and even on the route you drive every day to work," he says. "If you see something that's not right, let us know. Even if it's an excavation for a house, and there's a row of trees that have become unstable, let us know."

To report a potential hazard tree issue, please call our Customer Care number (1 800 224 9376, or 604 224 9376 in the Lower Mainland).

Trees near smaller 'service lines' to your home are your responsibility

While it's our job to prune or remove those taller trees that may come down on our transmission or distribution power lines, it's up to you to prune trees – or to hire a professional to prune them for you – to ensure the service line to your home is clear of vegetation.

"A service line doesn't need three metres of clearance like our other power lines," he says. "It has weatherstripping that acts as a form of insulation. A service line needs a hole, in which it can go through a hedge or through a tree canopy.

"You have to ensure there's no branch sitting on it, rubbing on it, because over time it will rub through the insulation and cause power interruptions."

We recommend that you get a qualified contractor to prune a tree, in part because not everyone has a safe, dependable stepladder or the proper tools to do the work. Hallaway says that in most cases a landscaper will have the expertise to get the job done right.

Image of arborist trimming a cottonwood tree
Following the unusual end-of-summer windstorm of last August 29th, a BC Hydro customer let us know that an 80-foot cottonwood tree on her property was weakened by the storm. After confirming that the tree was damaged, BC Hydro brought in a contractor to take down the tree.

Planting trees? Choose the right tree for the right place

When you're about to plant a tree or shrub, plan carefully. Be aware of power lines – see this visual guide to types of power lines in our system – and consider the final height and width of the vegetation when it's fully grown.

There are three zones around overhead power lines:

  • Low zone: This area extends five metres on either side of the power line. Trees planted here should have a maximum mature height of 6 metres or less.
  • Medium zone: This area extends from the edge of the low zone to a distance of 10 metres from the pole and power line. The maximum, mature height of trees in this zone should be 12 metres.
  • Tall zone: More than 10 metres from power lines and poles, virtually any strong, healthy tree is fine to be planted in this area.

Overheight trees in the medium zone cause the majority of outages. Falling branches and toppling trees can bring down power lines, causing power interruptions and severe safety hazards.

You can also refer to our Planting Near Power Lines guide [PDF, 1.6 MB] for detailed information on vegetation height restrictions and recommendations for selecting the right plants and trees for your region.

Call or 'click' before you dig

Did you know that about 12% of our power lines are below ground? Every time you dig in the ground, you run the risk of loss of life or damage to property if you hit a buried cable, conduits, gas or oil pipeline. And that's where BC One Call comes in.

Whether your project is big or small, the best way to ensure your safety is by getting in touch with BC One Call. It's free and easy. Within three days of your initial phone call or online request, you'll have information about what's buried in your yard and where it's unsafe to dig or excavate. You'll also have someone you can contact at each utility, and in your municipality, if you need any help or require more information.

See also: