The Okanogan County Public Utility District (PUD) is shutting down construction of its Pateros-Twisp transmission line project for the winter, and will resume construction on the line next spring, the PUD said this week.
Under mitigation measures outlined in the Environmental Impact Statement (EIS) for the project, construction activities cannot occur during the winter months to avoid potential impacts to mule deer winter range and bald eagle use, the PUD said in a press release.
Work on the project includes building out the new line from Watson Draw to the Twisp substation, establishing access to the right-of-way, structure locations, and installation of poles. Project contractor Michels Power has installed 233 of the 255 structures as designed for the 27-mile project, the PUD said.
About 160,000 feet of the nearly 800,000 feet of required conductor (power lines) was installed, the PUD said.
When construction resumes, work will include installing the remaining structures and stringing conductor along Highway 153 and overland from Watson Draw to Highway 153.
The PUD said the project is targeted for completion by mid-summer 2017. When complete, the transmission line will create a loop feed to the Methow Valley, improving electrical reliability and reducing electricity losses, according to the PUD.
Michels Power 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 had been working on the final 6-mile stretch that runs along the highway from Benson Creek to the Twisp substation.
The PUD has received calls from people curious about the new poles, which are larger than some people had anticipated, said Allen Allie, the PUD’s construction design manager. 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.
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.
Crews will remove the old poles once the new line is finished, he said.