Vegetation Management

Effective management of vegetation in and along the transmission corridors is essential to reliability and safety. 

BPA owns and maintains over 15,000 miles of high-voltage transmission lines across Oregon, Washington, Montana, Idaho and parts of Wyoming, Nevada, Utah and California. BPA works with land owners, government agencies and community groups to manage vegetation and ensure public safety for individuals working near high-voltage transmission lines. 
Tower diagram

National Vegetation Management Standards

The North American Electric Reliability Corporation, or NERC — a national regulatory body that oversees reliability of the U.S. power grids — requires BPA to follow strict vegetation management standards for electric transmission lines.

Under NERC vegetation management standards, BPA’s must manage vegetation to keep a safety zone between high voltage transmission lines and the trees and brush beneath and around them. A key factor is the potential mature height of the tree, and another factor is the maximum distance the power line will sag during periods of high use. When power lines carry more electric load, they heat up, which causes the wire to expand and sag. In summer, for example, when the air is hot and customers demand lots of electricity, lines can sag up to 14 feet.

Safety is at the core of what BPA does.

Trees and power lines have never been good neighbors. That’s why BPA works hard to keep a safe distance between high-growing vegetation and nearby power lines through a comprehensive vegetation management program. Even though BPA regularly inspects its transmission lines, you can help by notifying BPA if you see trees or vegetation that might be growing too close to  the lines. For your own safety, it’s important that you never attempt to trim or remove a tree that’s near a transmission line on your own. Working around energized power lines is very hazardous. Instead, call BPA and its specially trained crews will take care of it.

Learn more about power line safety

How BPA manages vegetation

Private Property

BPA respects property rights and strives to keep landowners informed and minimize any impacts to property. When impacts cannot be avoided, BPA will work toward mutually-satisfactory solutions.  Before starting vegetation management activities, BPA makes every reasonable effort to contact landowners and residents near the project area to inform them about scope and timing of the vegetation management work to be done.

Access roads

BPA needs reasonable access to transmission facilities to perform necessary maintenance and repair and to make sure vegetation or structures do not pose a safety or electric outage threat. During emergency maintenance, trees blocking access roads or impeding access to work zones or structures will be cut and removed. 

What can I do to stay safe while growing and maintaining crops?