Vegetation management

Vegetation management near distribution lines

Managing trees and vegetation near power lines is an essential part of maintaining reliable service and reducing wildfire risk. As our crews work through your neighborhood, we provide several vegetation management services at no cost to you. This includes routine tree pruning to maintain safe clearances and, in some cases, the selective use of tree growth regulators to slow the growth of fast‑growing species. When a tree presents a safety or reliability concern, it may be identified for removal. Trees under 6 inches in diameter at chest height and not intentionally planted as part of the landscape will also be removed to prevent future conflicts with power lines.

To prevent regrowth and maintain long‑term clearance, we apply low‑volume herbicide to non‑landscape trees and directly to cut tree stumps. All products we use are registered with the U.S. Environmental Protection Agency and applied in accordance with federal, state and local regulations.

Below are images of common tree shapes and clearances you may expect after pruning.

Vegetation Management FAQ Handout | En español

Vegetation management near high-voltage transmission lines

Maintaining safe, reliable electric service starts with keeping a clear right‑of‑way around our transmission lines. These high‑voltage lines are the backbone of the electrical system. Because a single outage on a transmission line can impact thousands of customers, we follow strict safety and reliability standards to keep these corridors clear.

As our crews assess the transmission right‑of‑way, trees and vegetation that pose a risk to public safety or system reliability are typically removed. Several factors guide our decisions, including line voltage, sag and sway of the conductor, topography, and whether a tree is located within the wire zone or border zone. These considerations help ensure that vegetation does not encroach into required safety clearances, especially during wind, snow or high‑temperature conditions.

This work is essential to protecting communities, preventing outages and supporting safe, reliable power througout the region.

See below to understand where trees should and should not be planted near high-voltage transmission lines.

Wildfire prevention

As wildfire risk increases, we're working to reduce the potential for wildfire ignition on and around our system. In areas with elevated wildfire risk, we implement enhanced vegetation management and inspection practices designed to strengthen safety, reliability and system resilience.

We perform vegetation inspections more frequently to support early hazard detection. When a hazard tree is located, we attempt to seek the property owner’s written permission prior to tree removal. In some cases, where we are unable to reach the owner, removal without permission may be necessary for public safety.

We provide extra clearance when pruning to improve safety and reliability. This added clearance helps reduce the likelihood of vegetation contacting power lines during high winds or hot weather.

Another important prevention measure is pole clearing, which removes vegetation and combustible materials around the base of subject power poles. This work helps reduce ignition risk if sparks or hot materials are released from electrical equipment. Pole clearing maintains the space 8-feet-high and within a 10‑foot radius around power poles.

Tips for planting

To reduce the need for future pruning, it's best to choose an appropriate tree for the space using the guidance below. Remember to call 811 at least 48 hours before you plant to have underground utilities located.

Overhead power lines

• For small trees (mature height under 20 feet), plant at least 20 feet from the pole.
• For medium trees (mature height 20–40 feet), plant at least 40 feet from the pole.
• For large trees (mature height over 40 feet), plant at least 60 feet from the pole.

Underground power lines

Trees and shrubs should be planted away from pad-mounted transformers so crews can access equipment to make repairs and maintain the electric system.

• Keep at least 10 feet of clearance in front of the transformer (the side with the door/hatch)
• Keep 3 feet of clearance on each side; this includes all vegetation that could potentially block access

Planting to help save on energy costs

• Plant deciduous trees facing southeast and southwest for summer shade and winter sun.
• Shrubs and small trees can be placed to shade air conditioners and heat pumps. Be careful not to block air flow, and consider ways to keep units free of leaves and needles.