Tree Maintenance Program
Inspection and Notification
Many of Pacific Gas and Electric Company’s contracted pre-inspectors are Certified Arborists. This means they have passed a qualifying exam and continue their training through courses approved by the International Society of Arboriculture (ISA). An inspector’s primary role is to identify trees growing too close to the high voltage power lines as well as trees and limbs that have the potential to fall into the lines.
During the annual patrol pre-inspectors will determine:
- Which trees will be trimmed
- The type of trim (directional trim, side trim, etc...)
- The desired amount of clearance to achieve between the tree and power line.
Inspectors will assess the site location, growth rate of the tree and the proximity to the lines when deciding upon an acceptable amount of clearance to prescribe. A reasonable margin of distance beyond the minimum clearance requirements will be factored in to allow for growth, wind sway and other environmental factors. A general rule of thumb is to create a clearance of 12 feet between the power lines and the canopy of the tree, but may be as much as 20 feet of clearance for fast growing species such as a mulberry or eucalyptus tree.
Once a tree has been identified for trim it is marked with a paint dot at the base of the tree. The property owner should be notified either in person or with a door card before the work is to start. Work orders are then generated for the tree crews to perform.
Our inspection companies are separate from our tree trimming companies. For more information, visit our PG&E and Contractors information page.
Utility Tree Pruning Practices
Utility tree pruning utilizes the technique of Directional Pruning, a method recommended by the International Society of Arboriculture (ISA), American National Standards Institute (ANSI) and the National Arbor Day Foundation. This method removes entire branches to the main trunk of the tree where they would normally be shed. This type of trimming helps the tree ‘naturally’ protect itself from diseases and insect attacks. Directional pruning reduces growth toward the power lines by encouraging growth away from the lines. Trees trimmed this way will be less susceptible to pest and diseases and will promote a healthier tree in the long run.
The trees may appear unbalanced, but a healthy tree is able to react to the changes and the visual appearance will soften over time. Some trees, such as redwoods or palms can not be directionally pruned. These trees grow straight up from a central leader which, when planted directly under the lines must be topped or removed entirely. Some homeowner’s may feel further work is required to meet their landscaping needs. In that case, PG&E will trim the tree to a clearance that is safe to allow any licensed tree company to perform additional work at the home owner’s expense.
When a tree is deemed hazardous or can not be pruned effectively without significant impact to its health or shape, it should be removed. Property owners will be asked for permission to do so, and details of clean-up will be arranged at that time. A tree for removal will be marked with an “X”.
We also pursue the removal of small fast growing trees growing directly under the lines. PG&E encourages homeowners to remove trees that are in continual need of pruning and replace them with a more suitable species. If you have a tree in mind for removal, contact us at 1-800-743-5000 requesting a site visit from PG&E's Vegetation Management Department.
Tree Crews are instructed to remove or chip all green debris under 4" in diameter that is accessible from the road. Larger limbs, trunk wood and dead material will be left on site for the customer. Mulch made from prunings is available through our free wood chip program. Please call us at 1-800-743-5000 if you would like to have chips delivered to your property or to be notified of chips that may be located in your area. A load of chips is about 10 cubic yards of mixed tree material.
Outages and Storm Work
During emergency situations our efforts are focused on public safety and restoring power as quickly as possible. Tree debris from storm activity will be left on site. Additionally, it may be necessary to trim or remove vegetation without acquiring the home-owners permission first. If you see a tree that may be a hazard or in contact with the lines; please notify us by calling 1-800-PGE-5000.