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Puget Sound Energy transmission line project

Cottage Brook-Stillwater-Novelty transmission line


2017 project updates

  • Construction of the transmission line was completed in September 2017, and the upgraded line is now energized.
  • Crews also trimmed trees, upgraded distribution lines and installed tree wire. Tree wire is a specially coated, overhead wire that significantly reduces the frequency of tree-related outages.
  • The final section of distribution work, along with final restoration and clean-up of the work areas, will be completed by the end of 2017.
  • Old poles will remain in place until telecommunications companies transfer their attached communications cables to the new poles. Once that is complete, PSE will remove the remaining poles.
  • Thank you for your patience during construction!

Project overview

The existing electric transmission system serving customers in parts of Duvall and unincorporated King County is almost 100 years old and approaching its capacity limit, putting the homes and businesses that rely on it at risk of outages. The lines were not built to meet the needs of a 21st century community, and can become overloaded during periods of high energy use, such as on very cold or very hot days. In addition to the limitations of the small-capacity conductor, the current height and configuration of the poles increase the possibility of damage and outages due to trees and tree branches.

By rebuilding the existing transmission lines with higher-capacity wire, PSE will improve the reliability of the electric system that serves you and your neighbors and ensure that PSE can meet the future energy needs of the community. Specifically, PSE rebuilt approximately 6 miles of existing power lines between the Cottage Brook substation near Woodinville and the Stillwater substation south of Duvall.

Past related work

  • In 2016, we transferred a particularly vulnerable part of the overhead distribution line (Cot-13 distribution circuit) near the Cottage Brook substation from overhead to underground along the Seattle Public Utilities Tolt Pipeline Corridor near Mink Rd NE. Placing this distribution line underground will lower the risk of outages.
  • In 2014, crews replaced the existing overhead transmission line between the Novelty Hill and Stillwater substations.