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Trees, Safety and Electric Reliability: Frequently Asked Questions
How can trees affect my power?Trees can affect service reliability and interrupt power to customers. In worst-case scenarios, heavy snowfall or strong winds can cause trees to knock down power lines or break poles.
To help keep trees away from our lines, we hire qualified line-clearing contractors to prune trees on a regular maintenance cycle.
Are there safety issues surrounding trees and power lines?Most lines are not insulated. They are bare wires. A tree or limb that grows into or falls across two wires on the pole can create a path for electricity. When this happens, protective equipment usually shuts off the line.
You should never climb or prune trees near power lines because you or your equipment could contact an energized line. Serious injuries or death could occur if a person touches energized power lines.
My trees haven't caused any power outages. Why are you pruning or removing them?Idaho Power clears vegetation from around power lines before trees and brush are close enough to cause outages. This approach helps us maintain a safe, reliable supply of power.
What if there’s a problem with a tree affecting the service wire that runs from the power pole to my house?Pruning trees away from a service wire (see example pictures below) is not part of our routine line clearing maintenance.
However, we caution all homeowners to take care when pruning any vegetation near power equipment. Only trained professionals should prune trees around power lines. Stay at least 10 feet away from overhead lines, and contact Idaho Power if necessary.
If a branch near a service wire is determined to be a problem, we can de-energize the power line during normal business hours at no charge so the customer can make the necessary prunes.
Will I be notified before a tree crew comes to clear lines in my yard or neighborhood?We leave door hangers on each customer’s door before crews arrive for routine maintenance work scheduled for the area. We are unable to provide prior notification in emergency situations.
When is the best time to prune trees?Most professionals recommend extensive pruning in the dormant season (during winter, when trees don’t grow). Minor pruning can occur any time of year.
When and how often does Idaho Power clear lines in my area?We employ a systematic approach to maintaining our more than 20,000 miles of overhead power lines. Depending on the conditions on a given line, our maintenance cycle is between three and six years.
How much will be cut from my trees?Each tree is different and must be considered individually. Trees with trunks close to power lines require much heavier pruning than trees that are farther from the line.
Some techniques that are appropriate on hardwood trees cannot be used on some softwood species. When pruning, our experts make every effort to provide enough clearance for the tree to remain safe until the next time it is pruned.
See example clearing techniques.
Does Idaho Power “round” or “shape” trees?We do not “round” trees over because it’s not good for the health of the trees. We follow the ANSI A300 tree pruning standard and use a method of pruning called directional pruning. This method is endorsed by many in the tree-care industry as the best technique for the health of the tree.
Directional pruning removes each limb where it joins another limb or at the trunk. This procedure is different from “rounding” trees over, where limbs are cut at random points, normally leaving unhealthy “stub” cuts.
Directional pruning involves cutting a limb back to another limb so future growth is directed away from power lines. With the directional technique, tree growth causes minimal impact to public safety and electric service.
Are the line clearers trained professionals?Yes. Each crew has at least one certified arborist or person who has completed an advance course in arboricultural training. The area supervisors, Idaho Power utility arborists and staff notifying customers in advance about line clearing are all certified arborists.
Is there a charge for line clearing on my property?The cost of managing the natural growth around power lines is part of the prices approved by the public utility commissions in Idaho and Oregon for providing power. There is no separate charge.
Can I clear the lines myself?Only trained professionals should prune trees around power lines. Serious injuries and even fatalities have occurred when untrained people do this work themselves.
Please contact us online or call us at 208-388-2323 from the Treasure Valley area or 1-800-488-6151 for an evaluation of the trees and vegetation around power lines prior to any removals.
What types of trees or plants should be planted near transformers and power lines?If vegetation is needed under power lines, trees with a mature height of less than 25 feet are best. Avoid planting shrubs near padmounted transformers (the green boxes you sometimes see in neighborhoods). Transformer maintenance work requires 10 feet of clearance in front and 2 feet on the sides and back.
Is Idaho Power responsible for clean-up after line clearing?Our policy is to chip any small limbs, branches and brush from landscaped settings. Idaho Power will haul this material away or leave the mulch with the property owner at their request. Any wood larger than four inches in diameter is cut into manageable lengths for the property owner. Dead wood cannot be chipped and will be left on the property.
In non-landscaped sites, pruned vegetation and wood is left in place to biodegrade.
When severe weather causes trees or other vegetation to fall across power lines, causing power outages, we cut the trees and brush so poles and lines can be replaced and re-energized. Disposal of any wood, limbs or debris resulting from this type of emergency operation is the property owner’s responsibility.
Do you need my permission to clear lines on my property?Idaho Power has easements to the property that allow us to maintain our lines. While we do not need permission to prune, we notify our customers via door hangers when access to their trees or property is necessary for the safety and reliability of our power lines. We are unable to provide prior notification in emergency situations.
What happens if I refuse access to my property/tree?Idaho Power is obligated to keep lines clear to provide safe, reliable power to the community and our customers. We can, as a last resort, pursue legal means.
Do I need to be present when line clearing is performed?No, unless you need to unlock a gate or control pets.
Can I have my own tree pruning service do the job rather than Idaho Power?No. Only specifically trained professionals can work within 10 feet of a power line, and many tree pruning companies don’t have such professionals on staff. Idaho Power clears lines at no cost to the customer, and we try to make it as convenient as possible.
Do you repair cuts made from pruning?No. Repairing cuts has been found to be ineffective for slowing growth or preventing disease.
Can mulch or chips from the pruning be left with the owner?Yes, at the customer’s request. The chips are not sterilized and could include thorns, branches or pesticides.
Do you clear branches away from telecommunication and cable TV lines?No. It is the responsibility of the phone and cable utilities to prune trees or vegetation around their lines.
What happens if my tree dies after pruning?If it is clear that pruning killed the tree, Idaho Power will cut it to a stump and provide the customer a voucher to replace the tree.
Why don't you relocate your overhead lines to underground?Idaho Power usually installs power lines above ground (also called overhead lines). This is the most cost-effective option. Installing power lines underground is usually cost prohibitive for customers, but Idaho Power is willing to relocate overhead lines to underground if a customer is willing to pay the cost.
Contact Idaho Power for a price estimate.