Tree Planting and Trimming
Trees that grow too close to power lines can cause outages, start fires or create other hazardous conditions. Generally, we remove trees that pose a serious threat to safety and electric service. Not only does this work help maintain electric safety and service reliability, it is required by state and federal regulations (National Electric Safety Code, Rules 012, 013, and 218).
Because our tree maintenance activities can have a profound affect on the appearance of trees, the value members place on high-quality electric service will sometimes conflict with the value they place on trees in their community.
How do we prune?
We hire professional local arborists to maintain a safe corridor around power lines. They use International Society of Arboriculture (ISA) best management practices for utility trimming to maintain the health of the trees. This method, besides being healthier for the tree, also reduces re-sprouting in problem areas and limits the length of sprouts that do occur. The tree’s species, structure and the strength of wood are all considered when trees are pruned.
In addition to pruning, trees not intentionally planted as part of the landscape that measure less than six inches in diameter at 4.5 feet high will be removed.
If you’d like a tree pruned or removed for landscaping purposes, you’ll need to hire a private tree removal contractor to perform the work. If necessary, we can disconnect a service line for their workers’ safety.
How much do we prune?
Pruning clearances depend on tree species and growth patterns and the voltage of nearby power lines. Around distribution lines, which are typically found in neighborhoods, we provide at least 10 feet of clearance. Fast-growing species (willow, Siberian elm, cottonwood, and box elder) require 14 feet of clearance while slow-growing species (spruce and oak) require at least 10 feet of clearance. One challenge of utility right-of-way trimming is to remove enough material to comply with the Oregon Public Utility Commission's minimum clearance requirements until we return to trim in 2-3 years.
Sometimes the best solution to tree and power line conflicts is tree removal. We work with neighborhoods to remove problem trees, particularly in cases where they require repeated pruning. Tree removal is especially important where pruning alone cannot achieve safe clearance from power lines.
Along stretches of road where there are no houses, we remove problem trees from the public right-of-way. It saves our members money to remove them rather than trim repeatedly. We would never remove yard trees without first talking with the homeowner, though we might trim them if we're unable to reach the homeowner beforehand. We work with the wishes of our members whenever we are able to without endangering our personnel or the reliability of the system.
What can you do to help?
While OTEC maintains a rigorous tree-maintenance program for trees along power line right-of-ways, approximately 90 percent of tree-related outages are caused by trees growing outside of the right-of-way – for example, a tree growing in a front yard rather than a parking strip.
What happens if I refuse OTEC or its tree pruning crews access to my tree?
OTEC is obligated to keep lines clear to provide power to the community and our members. We can, as an absolute last resort, pursue legal means.
Why don’t you relocate your overhead lines to underground?
The cost to install underground lines is $5,000 to $10,000 per homeowner, minimum.
Underground cable life is typically less than 20 years. Any time a cable fails, OTEC would have to dig down and repair the faulted line. In addition, relocating overhead lines to underground cable often destroys a tree’s root system.
Can the time of year for line clearing be changed?
No. The tree service works in cycles. It is inefficient and costly to move out of the cycles. With proper pruning, time of year will not affect the health of the tree.
How often are you going to prune my tree?
About every two years.
Why are you asking my permission to prune?
Technically, we are performing a notification of work to be performed. We do this as a courtesy to you, our member. We have easements to the property, which provides us access to maintain our power lines.