We have a tree problem
by Ian Brizdle | Oct. 24, 2019
In the early morning hours of Aug. 26, 2019, a large Albizia tree fell across Lai Road in the back of Palolo Valley on Oahu. Residents that live back there in the Palolo jungle, including my parents, woke up to a familiar situation for them — no electricity service, and the inability to drive through the one access road to their property. It was a repeat of what had just occurred earlier this year in February, in almost the same location.
The first thing my parents did was report the outage for their specific address using the Hawaiian Electric Mobile app on their cell phones. The outage map tool also showed them that we were aware of the outage in their area and our estimated time of restoration. With nothing else to do until then, naturally they walked down the road to check out the damage, nose around and take pictures.
Cleaning up the carnage
When trees unexpectedly fall over power lines, the damage can be extensive and dangerous. The weight from large tree limbs on lines can easily cause utility poles and equipment to break, and energized lines can become loosened and fall to the ground. Our company’s first focus is to secure the scene and safely remove the tree/branch from the lines in order to get the road clear for vehicles to safely pass. Notice the emphasis on safety — energized power lines on the road can be an extremely dangerous situation and we advise everyone to keep a distance of 30 feet or more if they see a downed power line.
Most times, like in the case of the Lai Road incidents, we need to deenergize the lines so that our contract trimmers can work safely on the tree that is resting on the conductors. This process can be time consuming since there is often a lot of tension placed upon lines and equipment, and removing weight safely from those lines poses a risk to personnel and equipment. Once the trees or branches are safely moved out of the way, then our crews can assess the damage and begin repairs to poles and lines as necessary.
What are we doing to prevent this from happening?
Our Vegetation Management department works hard to prevent trees from contacting our distribution lines. There are two main areas of focus for trimming: 1) roadside distribution lines that are usually accessible by a lift truck, and 2) off-road rights of way which is mainly our higher voltage 46kV and 138kV lines that run across the mountains and in more inaccessible areas. These areas are usually only accessible via foot or in some cases helicopter.
We trim Oahu on a cyclical basis. In essence, we start at point A and go around the island area by area until we get around to point A again. Ideally this takes us anywhere between 20–24 months. Crews will generally prune to get 10–15 feet of clearance from our high voltage lines. Less clearance is achieved for our lower voltage secondary lines, and service lines to each particular home is usually the responsibility of the homeowner.
We currently have four different contractors performing work for us. Our five-year average on the roadside distribution side is roughly 81,000 trees trimmed or removed each year. For the off-road rights of way side, we average 137,000 trees trimmed or removed in the same span. This type of vigilant maintenance is effective in increasing our resilience to high-wind situations and storms by decreasing the amount of potential damage as a result of fallen trees.
What can you do to help?
If trees or branches on your property are near your service line (the line connecting to your house), this may fall outside of the scope of our routine vegetation maintenance. We suggest that customers ALWAYS hire what we call a “Line Clearance” qualified tree trimmer. These workers have received specialized training for safely working near energized power lines.
If you are concerned about trees on or near your property, please visit the Tree Trimming Safety page on our website for more information about safety and contact information.
Ian Brizdle is a digital communications analyst at Hawaiian Electric Company.