(WSB photo: City Light truck on Highland Park Way during Sunday night’s outage)
The question came up again after Sunday night’s 2,100+-customer power outage from Puget Ridge to White Center: Since the line along the Highland Park Way hill seems to be particularly vulnerable, wouldn’t it make sense to put that line underground? We took the question to Seattle City Light.
Short answer: No.
Long answer, via SCL spokesperson Connie McDougall:
I’m told that the utility is aware of that area’s outages, and of course regrets the inconvenience, but City Light does not consider an underground system to be a viable solution for that area.
As one person told me, these kinds of projects are not only enormously expensive, but also very complex. Some folks might think it’s just a matter of digging a trench and then installing power lines but it’s not that simple. There’s a lot to consider.
Part of it is environmental. Crews would have to remove hundreds of healthy trees in the greenbelt area to make way for such a system, which in turn would damage roots of nearby trees. Also, by mayoral executive order, when crews remove one tree, they must replace with two suitable trees. Just making room for that scope of planting would mean thinning out hundreds of additional trees, adding to the cost to say nothing of aesthetic issues. Also, there are protected wetlands in the area, which further complicates it.
The other reason City Light would not consider an underground system viable for that area is our commitment to cost effectiveness. Even if you could somehow overcome all of the environmental issues, this would be a multi-million dollar job, using funds the utility simply does not have. Like everyone else, City Light has to stick to a budget and must make decisions and choices that are fiscally responsible.
To reduce tree-related outages, City Light’s vegetation management folks did trim the trees immediately around the wires in that area in May of this year. They trim about 10-feet around the powerlines, perhaps a few feet more depending on the situation. They try not to cut any more than is necessary for both practical and aesthetic reasons. The tree that caused your recent outage last weekend was not in that trim zone, but had a large reach, so when it went down, it went into the lines. This is just the nature of a greenbelt. And again, for practical and aesthetic reason, crews never trim trees deep into an area, but only around the wires.
This may not be any consolation, but you may also want to tell readers that when there’s an outage underground, it takes much longer to find it and repair it. Crews literally have to look into all the vaults in the area until they find the one with the problem. Overhead outages are a lot easier to find and repair, so customers get their power back sooner.
In newer construction of course, developers and contractors can plan for underground systems and build it into the cost and scope of the project.
Other tree-linked outages traced to that stretch include last August and March 2014; in November 2013, a car-vs.-pole crash there caused an outage with the same basic footprint. Those are just the ones we found easily in our archive, which also includes the signature sign of the 2006 Hanukkah Eve windstorm aftermath,
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