Identifying High Voltage Power Lines

How to identify high voltage power lines.

It is important to identify whether high voltage power lines are above the planting strip where you will plant your new street tree. If high voltage power lines are present, your tree list will provide options for smaller form trees. Smaller form trees are less likely to grow into the high voltage power lines.

Wires above trees are categorized as either high voltage or not high voltage. High voltage wires often (but not always) run on one side of the street and have some features which make them easy to identify.

Signs that wires are high voltage:

  • Transformers
  • Insulators
  • Trees along the street are pruned away from the wires

Signs that wires are not high voltage:

  • Service lines (lower voltage power lines) and communication lines will not have transformers or insulators. You might see these lines connecting to houses or running through trees. 
High Voltage WiresNot High Voltage Wires
high-voltage wire with transformer and insulator

Transformer and insulator present

overhead communication and service wires

Communication and service lines

trees pruned away from overhead wires

Tree is pruned away from high voltage power lines

trees growing through overhead wires

Tree is growing through communication and service lines

Contact your electric company

Portland General Electric

Tree Trimming 503-736-5460 or 800-544-1794

Pacific Power

Tree pruning & vegetation management: 1-888-221-7070