What is the Distance a Tree Limb Should be from Power Lines?

Trees and Power Lines

• Strong winds or heavy rain or snow can cause tree limbs to sway and break, and if they damage power lines, this can cause an electrical outage and will also pose a fire hazard. When a tree limb comes in contact with a energized line, it can drain off some of the voltage, which can cause damage to appliances and electrical equipment. Tree limbs constantly rubbing up against or touching power lines can cause stress, resulting in a fire and safety hazard.

Planting Distance

• If you are planting new trees or shrubs, plan ahead so that they don't interfere with existing power lines. The city of Seattle recommends that only small trees and shrubs with a mature height of 25 feet or less should be planted directly underneath power lines. Larger trees that reach a height of 25 to 45 feet should be planted 20 to 50 feet away from power lines, and trees that grow over 45 feet tall should be planted at least 50 feet from electrical wires.

Trimming Trees

• How far a tree limb must be from utility lines depends on the variety of tree and how much the limbs sway in the wind. Ten feet is a good minimum distance between a tree limb and a power line. Your local municipality might have different requirements, and your electric company can help you determine if, and how much, your trees should be trimmed.

When to Call an Expert

• Trimming tree limbs near power lines is dangerous business and is a task best left up to professionals. If your pruners or a tree limb you are touching comes in contact with a live wire, you can be seriously injured or even killed. Some states may require that any tree trimming within 10 feet of an electrical wire must be done by a trained and certified arborist. Electrical companies often do their own trimming near their company's lines, or, in some cases, you may hire a licensed private contractor authorized to work near local lines. If you are trimming or removing a tree in your yard that is under the service cable that runs from the pole to your house, your electric company may be willing to cut off power to your house for the duration of the pruning work.