TREE TRIMMING FAQS
Why does Boulder City Electric Division trim trees?
Our tree trimming program is intended to help protect you and your property while maintaining electric reliability.
Why does Boulder City Electric Division trim trees on private property?
Sometimes trees on private property will grow into or near high voltage lines, so we trim branches to prevent danger to the public and damage to our equipment. We will also remove trees where the trunks are too close to the power lines.
Who does the work?
We have skilled and specially trained staff and selected contractors who have received training to meet OSHA and ANSI (Z133.1-2000) requirements to approach and work close to high voltage power lines.
How often are trees trimmed?
Boulder City Electric Division typically allows for an average of three years’ growth between each trimming, depending on the type of tree and other circumstances. At the time of trimming, we will seek at least 10 feet of clearance between high voltage power lines and tree limbs. Trees don’t need to be touching the power lines to require trimming -- they will be trimmed on a cycle if they are growing into the clearance space. Achieving this required clearance may mean trimming on your property.
How are trees trimmed?
We follow the trimming practices recommended by the International Society of Arboriculture and described by Dr. Alex L. Shigo in his book "Pruning Trees Near Electric Utility Lines: A Field Pocket Guide for Qualified Line-Clearance Workers", including:
- Techniques consistent with the practices of natural, lateral and drop crotch trimming.
- Cuts made back to a main stem or branch of sufficient size. In no case will deciduous tree limbs be stubbed off at the edge of the clearing limits.
- Trimming cuts made to direct future growth, wherever possible, and sprouting away from the conductors.
- Conifers are trimmed in a manner that allows them to retain as much of their natural shape as possible.
- Removal of all dead branches overhanging primary conductors at any height.
- A minimum number of cuts to achieve required clearances.
- Cuts primarily restricted to large diameter branches made well within the crown, where practical. Shaping through the use of many small diameter branches in the outer crown will be avoided.
- Removal of living branches by making cuts as close as possible to the branch collar, and removal of dead branches by making cuts as close as possible to the living tissues that surround the dead branch at the base.
Who has responsibility for trees and power lines?
Inside the power corridors, tree trimming and removal is Boulder City Electric Division's responsibility. Boulder City Electric Division will trim or remove trees outside the power corridor when these trees could interfere with or fall into the line and create a hazard.
It is the property owner's responsibility to keep trees clear of the electric service line that runs from the pole to the owner's house. Boulder City Electric Division recommends the use of a trained tree trimmer to do this work. It is Boulder City Electric Division's responsibility to keep trees clear of its power lines.
What about palms?
Because of the way palm trees grow, they cannot be trained to avoid power lines the way other trees can. As such, most palms that grow under or very close to high voltage power lines will have to be removed, and Boulder City Electric Division will cut the palms close to the ground at its own expense as a courtesy to customers.
Why not just shape trees?
While once a popular practice, shaping is now considered horticulturally unsound. Shaping damages, a tree's health and creates a hazard to people, property and overhead lines. Shaped trees grow back quickly with vertical suckers sprouting from the cut ends of branches. These suckers are weakly attached to the branches and can break off in moderate winds creating wind-borne debris. This can lead to power blackouts and the need for far more frequent tree trimming. Proper trimming may look severe at first, but the trees grow back at a normal rate and are trained away from power lines. The health of the tree is maintained -- and even enhanced -- with correct cutting.
What can I do to help?
You can help us by thinking ahead when landscaping your property. Research the growth habits of trees and plants, including the size they will achieve when mature. Avoid planting trees near electric lines. If you must have a tree near our lines, plant only low-growing, compact varieties.