Chelan Transmission Fire Hardening

What

The Chelan Transmission Fire Hardening Project is aimed at reducing the severity and duration of power outages during wildfires on the high-voltage transmission system serving the Lake Chelan Valley. Replacing wood poles with steel poles will allow fires to pass by them without burning, meaning lines can either remain in service during a fire, or experience much shorter outages to de-energize the line while a fire passes.

Features of the project include:

  • Upgrading all transmission poles between Chelan Falls and Union Valley from wood to steel.
  • Ensuring clearances are compliant with regulatory requirements - which means some poles may be taller than existing structures, and some may be shorter.
  • Poles will remain in the same general alignment as they are currently, with some exceptions, although new pole locations will be offset slightly from existing poles.
Image showing comparison of steel and wood transmission structures

Why

The past decade has brought many large wildfires to Chelan County. The wildfire of 2015 in Chelan burned both transmission lines that serve the Lake Chelan Valley. Power was out for over 36 hours while the first line was restored. The second line took eleven days to restore. Outages of this duration can have impacts to commerce, tourism, healthcare, agriculture and the quality of life of all who live in the Lake Chelan Valley.

Results of the customer outreach from the 2015 - 2019 Strategic Plan indicated that 'customer-owners were most interested in replacing or rerouting some electric lines to protect against fire and weather risks". As a result, Chelan PUD conducted a fire risk assessment of the PUD’s high voltage electrical transmission system in 2017. The study provided the PUD with a list of transmission line segments that are candidates for fire hardening improvements. These improvements will minimize power outages, shorten outage durations, and improve the resiliency and reliability of the PUD’s transmission system. The transmission system between Chelan Falls and Union Valley was one of several projects identified in the study.

Chelan Complex Fire damage cropped

Community Outreach

On March 13, 2019, PUD staff held an informational drop-in session to gather community input on the Chelan Transmission Fire Hardening project, as well as the proposed Chelan Dam Substation. View an informational presentation here. On May 15, 2019, PUD staff held a second informational drop-in session about the project.

In October 2019, the PUD presented a 30% design concept and three build alternatives to adjacent property owners, and staked potential pole locations for review. Staff also held a third informational drop-in session on November 20, 2019. At the Chelan County PUD Board of Commissioners meeting on December 16, 2019, staff put forward and the Board approved a Preferred Alternative for the Chelan Transmission Fire Hardening Project – rebuilding the line from Chelan Falls to Union Valley in steel.


Timeline

Design will occur in 2020 and 2021, with construction planned for 2022.