PUD’s new transmission line is marching up the Methow Valley
Crews with Michels Power installed new power poles for the PUD’s transmission line near Twisp last week. Workers are trying to finish the segment along the highway before the ground freezes, but the 27-mile powerline won’t be complete until next summer.
By Marcy Stamper
The string of 75-foot-tall power poles nearing Twisp is tangible evidence that the Methow Transmission Project is nearing the final stretch, after two decades in planning and litigation.
Installation of almost all the new poles and structures — 210 of the 254 total — is nearly complete, although the majority are not strung with wire yet, according to Allen Allie, construction design manger for the Okanogan County Public Utility District (PUD).
Michels Power, the contractor installing the 27-mile line, started work this spring at the southern end of the route near Watson Draw, where the powerline taps into the existing transmission line between Brewster and Pateros.
Crews have installed all the structures in the more remote sections of the route, stretching 20 miles across the hills east of the Methow River to intersect with Highway 153. They are now working on the final 6-mile stretch that runs along the highway from Benson Creek to the Twisp substation, said Allie.
Crews are trying to complete that segment — including connections to lower-voltage distribution lines that serve customers — before winter forces them to stop work. With almost two months of construction work remaining, they are pushing their deadline, said Allie. Rain slows their progress, but snow and frozen ground would interrupt the work completely, he said.
The PUD has received calls from people curious about the new poles, which are larger than some people had anticipated, said Allie. Poles near the substation are about 4 feet wide at the base, tapering to 20 inches higher up, and are 75 feet tall. The old poles are narrower and just 45 feet tall.
Different poles
Design for the powerline specified different types of poles depending on the location, said Allie. Most of the structures between Watson Draw and Benson Creek are steel H-frames, which are 65 feet tall and not as closely spaced as the wooden poles.
Along the highway, the PUD is using round wooden poles, along with larger rectangular laminated-wood poles near the substation. The laminated poles are stronger and therefore don’t need to be secured by guy wires to connect to distribution lines and the substation, Allie said.
The powerline infrastructure along the highway will look somewhat different once the project is completed, said Allie. To avoid having to shut off the power while they work, the crews are using a technique that allows them to work while the line is energized. The “hot” rebuild involves placing existing wires on extensions on the cross-arms on the poles — usually sheathed in protective orange insulation — so that technicians can work safely. Once the work is complete, the extensions will be removed and the arms will not protrude as far, said Allie.
Crews will also remove the old poles once the new line is finished, so poles will be more widely spaced, he said.
In addition to the new high-voltage transmission line, the poles will carry a distribution line, phone wires and fiber-optic cables, which will be transferred from the existing poles along the highway. Part of the section that runs along the highway will have two distribution lines, one for the PUD and one for the Okanogan County Electric Co-operative.
Poles for distribution lines are typically closer together because they have to reach customers between the larger transmission-line structures, said Allie.
Two sets of wires — the high-voltage transmission wires and lower-voltage distribution wires — have already been strung on the first 2 miles at the southern end of the route.
Finish next summer
Work will resume in the spring and the entire route is expected to be strung with wires and operational by next summer, said Allie.
“It’s not a real fast process, but they’re going real good,” said Allie. “It has gone smoothly for the most part.” Encountering more rocks in the ground than they had anticipated in the section between Watson Draw and Benson Creek slowed their progress, said Allie.
Specifications for the project included the possibility of hand-digging that segment to avoid using heavy machinery on sensitive shrub-steppe land. Workers didn’t use shovels, but drilled the holes with an augur rather than blasting them, said Allie.
Because the poles were in small sections, crews were able to transport them without using heavy rigs, said Allie. They did not have to use helicopters, which had been proposed as a means of transporting materials to some of the more remote sites without damaging the ground.
Michels has two dozen people working on the installation along the highway, plus smaller crews doing restoration along other parts of the line, said Allie.
Planning for the transmission line began two decades ago, but the project was delayed by challenges in court over the environmental impacts of the line and the route itself. Ultimately the PUD had to resort to condemning land to obtain easements from a handful of private property owners and the Washington Department of Natural Resources.
When complete, the powerline will create a second route to bring power to the Methow Valley.
