In the wake of the most severe windstorms in recent years, Snohomish County PUD says it has stepped up efforts to work with local officials, businesses and citizens to enhance electrical system reliability and shorten outage times.

The first big windstorm hit in early December, breaking branches, blowing down trees and causing protracted outages to customers in South Snohomish County and throughout the PUD’s service area. No sooner had the damage been cleaned up than another storm hit in mid-January, putting many of the same customers back in the dark. A host of residences and businesses throughout the area experienced outages.

So what is the root cause of these outages, and why are some customers more adversely affected than others?

“Trees are the number-one cause of outages,” said PUD spokesman Neil Neroutsos. “While we’ve made some very significant progress in recent years, this winter’s storm events show that there’s more work to be done.”

In 2011, another year marked by severe windstorms, customers served by circuit 405 experienced an average customer outage time of 890 minutes, more than 10 times the 2011 overall system outage time of 83.3 minutes.

Those numbers prompted the PUD to fast-track tree trimming and other improvements, and in early 2013 the utility removed 19 problem trees and trimmed back 233 trees that were threatening power lines on circuit 405.

The results have been significant, bringing the 2013 average customer outage time on circuit 405 down to 24.2 minutes. For reference, the average system-wide outage time for 2013 was 84.5 minutes.

While trees are the number-one priority, the PUD is also looking at other ways to address the inconvenience and monetary impact of power outages including improvements to utility equipment and helping business customers investigate emergency backup generation.

“Keeping the power on and outage times to a minimum is a continuing challenge,” Neroutsos said. “The PUD is committed to meeting this challenge by working with all parties to strike the best balance between aesthetics and system integrity while being sensitive to community values.”

— By Larry Vogel