PG&E starts preemptive pruning in advance of winter

By Christina O'Haver, The Union Democrat December 10, 2012 09:02 am

PG&E is pruning and removing trees along its 130,000-plus miles of power lines, which run through Tuolumne and Calaveras counties, in effort to reduce power outages caused by falling trees. 

The process, called “reliability pruning,” is part of the electric company’s ongoing vegetation management program, according to spokeswoman Brandi Ehlers.


PG&E patrols the state year-round in search of trees encroaching on its power lines, and determines if the trees need to be trimmed or cut down.

The 6,800 miles of high-voltage transmission lines require more clearance than other areas to comply with the North American Electric Reliability Corporation’s “zero tolerance” policy. 

The policy, which was created in 2007 as a response to the Northeast blackout of 2003, requires PG&E to have zero vegetation-related power outages on those lines.

Trees subject to pruning are marked with a blue dot and those subject to removal are marked with a blue “X.”

PG&E notifies customers in work areas by “door-hanger” flyers, letters or personal visits.

Occasionally, residents raise concerns about trees on their property being pruned or removed. 

“We definitely work on a case-by-case basis with those customers,” Ehlers said.

If PG&E removes a tree on a property, it will sometimes provide the homeowner with a tree to plant elsewhere on their property.

The company’s “Right Tree, Right Place” program aims to inform homeowners of the kind of trees they should plant based on where they live.

“Those efforts are really to try to educate our customers in the hopes that they won’t do a beautiful landscaping project and we’ll have to come in … and either prune it or remove it,” Ehlers said. 

PG&E recommends choosing a tree that will not encroach within 10 feet of power lines when fully-grown. When trees are pruned, branches and brush are either chipped and spread across the property, cut to Cal Fire standards or removed. Branches or trunks more than 4 inches in diameter are usually left at the site.

“If we are completely removing a tree, that wood is the property of our customers,” Ehlers said. “It’s not our property and a lot of our customers like to keep that wood, especially up in the foothills, as firewood.”