The Pacific Northwest is beautiful, largely because of our lush forests and leafy trees. Trees, however, also cause half of our power outages. Especially when high winds blow through, following heavy rains like last weekend’s, falling trees and limbs can take down power lines and cause electrical outages.
“We live in a temperate rain forest,” said Jim Huggins, head of forest management for Clark Public Utilities. “Trees grow fast here, and the rapid growth means they have weak branch attachments that can break off more easily.”
To help prevent tree-related outages before they happen, Huggins manages a team of tree crews who work continually throughout the year pruning trees away from power lines. On about a three-year cycle, they trim trees growing in the utility’s right-of-way to preserve 1,500 miles of power lines. And that’s a big reason that Clark County has one of the most reliable electric systems in the region.
However, property owners’ trees can crash down on wires too. So Huggins’ team works with homeowners to keep big trees 10 feet away from high-voltage power lines, as regulated by Washington law. “We use the very best industry practices when it comes to tree trimming, and do as well as we can to keep the tree aesthetically pleasing and healthy,” he said. When customers spot trees in high-voltage power lines, reporting it is easy using the online tree trimming form on the utility website.
Sometimes pruning isn’t enough though, and the tree must come down. Recently, one of Huggins’ crews had to take out a 150-foot-tall sequoia that had grown into power lines. It was a big job because the trimmers had no place to drop sections of the tree without threatening the electrical equipment below. That’s why it’s important for trained Line Clearance Certified tree crews to do this kind of work.
Homeowners do have a responsibility to keep trees on their property from damaging the service wire feeding the home. When big branches fall on a line, they not only disrupt neighborhood power but also damage the weatherhead on the house where the cable attaches. Then, the homeowner must pay to replace or repair it to the latest building code, and have it inspected before power is restored.
If your tree needs more than a trim, Huggins suggests contacting the utility before an arborist. “Most outfits trimming trees aren’t Line Clearance Certified,” he said. “If needed, we can disconnect a line without charge and let the arborist prune the tree. When the work is finished, we’ll reconnect it quickly when the customer calls us.”
Property owners are also responsible for picking the right tree. “No trees reaching more than 25 feet should be planted under utility wires,” Huggins said. The utility lists suitable trees at www.clarkpublicutilities.com/resources/planting-trees-near-power-lines .
So why not put power cables underground? While many new lines are buried, where homes are far apart, it’s too costly to bury existing lines. Many stretches in heavily wooded areas now use coated “tree wire,” which dramatically cuts down on outages caused by limbs’ resting on lines.
The utility’s proactive tree-trimming, plus the use of tree wire and preventive maintenance of the system all combine to dramatically reduce storm-related outages in our county. Still, outages can occur and all are encouraged to prepare an emergency kit. Learn what to include at RedCross.com.
Energy Adviser is written by Clark Public Utilities. Send questions to ecod@clarkpud.com or to Energy Adviser, c/o Clark Public Utilities, P.O. Box 8900, Vancouver, WA 98668.
