Meet the team preventing power outages one tree at a time

When people think of restoring power outages, the vision of a lineworker appropriately comes to mind. Yet when you think of preventing power outages, chances are you may not think of an arborist. Given that the culprits of most power outages are storms, fallen trees, and increasingly, wildfires, ensuring BPA’s 15,000 miles of transmission lines remain clear of vegetation requires a skilled team working year round.
 
Meet BPA’s Vegetation Management and Forestry team. They manage the plants, bushes and trees along BPA’s rights-of-way to help ensure power is delivered reliability across BPA’s vast service territory. Their duties involve removing tall-growing vegetation within the ROWs, keeping transmission towers and structures clear of vegetation, and managing vegetation on access roads. 

The natural resource specialists on the team also identify damaged, dead or dying trees adjacent to BPA’s ROWs that could potentially fall and impact power reliability; they’re referred to as “danger trees” due to the threat they pose to the grid. The team also manages vegetation around substations, switch yards and microwave/radio sites.

The role of vegetation management in wildfire mitigation
Maintaining the vegetation near BPA ROWs is important not just to avoid trees or branching coming into contact with power lines, but also to avoid electricity arcing from a transmission line to a tree. Electricity can “flashover,” or jump from wires, through the air to trees, other vegetation or equipment up to 15 feet away, where it could cause a fire. 

Not only does managing the vegetation around transmission infrastructure protect it from falling trees, it also reduces the vegetation could serve as a potential fuel source for the outbreak of a fire. Generally, less vegetation means fires burn for a shorter time and at a lower intensity beneath and around structures than they would otherwise.

If it’s green and grows, the vegetation management team is involved
The vegetation management team also has foresters who identify trees for removal to provide adequate clearance when rebuilding or upgrading a transmission line. They also are involved with beam path communications, like microwave and radio towers, as they identify trees from Light Detection and Ranging analysis that may impact the signal strength between communication towers. LiDAR is a remote sensing method that uses light in the form of a pulsed laser to measure ranges. 

In addition to removing obstructive trees and shrubs, the team typically seeds about 20 acres a year on disturbed sites as well as partner with other entities to do planting when the opportunity presents itself. The team uses seed mixes that will benefit local pollinators. 

At the end of the day, the team’s biggest priority is to ensure the health and safety of their workers while maintaining reliable transmission. While they cannot predict every storm, fire or extreme event, BPA’s team of arborists and foresters can use their knowledge and expertise to identify and remove known hazards within and adjacent to the agency’s corridors before the power goes out through annual right-of-way inspections, routine scheduled maintenance, and emergency hot spot crews ready to mobilize with little notice. Over the years, BPA’s vegetation management program has become known in the industry as a leader in reliability and environmentally sustainable practices.