Electric reliability on Bainbridge Island needs to be improved – two-thirds of the island is served by two substations that don’t have backup transmission. The Winslow and Murden Cove substations are each served by single radial transmission lines, referred to as "taps". If the transmission line serving the substation goes out, then the substation and all customers served by that substation lose power.

As part of PSE's solution to improve reliability on the island, we’re planning to build the new "missing link" transmission line between the Winslow and Murden Cove substations to create a transmission loop. This means each substation will be connected to two transmission lines. If one line goes out, the other line can still feed the substation and provide power to customers.

This new transmission line is a critical component of PSE’s plan to improve electric service reliability, reducing the frequency and duration of power outages for customers on Bainbridge Island. More homes and businesses depend on PSE for reliable power than ever before and PSE’s investment in transmission infrastructure will make Bainbridge Island's electric grid more resilient and reduce the impact of any single outage by focusing on redundancy.

Bainbridge Island customers experience more frequent and longer outages than the average PSE customer, and nearly half of those outage minutes are due to issues with the transmission system. Some specific challenges to reliability include:

• Trees: Bainbridge transmission lines are heavily exposed to trees, which cause 64% of outages.
• Radial transmission lines: Nearly two-thirds of Bainbridge customers are at risk of a prolonged outage because their area is served by a substation – either Winslow or Murden Cove substation – fed by a single transmission line with no back-up.

Project timeline and milestones

The Missing Link is just one piece of PSE’s solutions package for Bainbridge Island, and we are working with other teams to coordinate work to accomplish all the projects cohesively. For instance, other Bainbridge Island projects require substation upgrade work, as does the Missing Link. These substation upgrades can only be done at certain times of the year, and on Bainbridge, we must follow a particular order of operations to accommodate all project work. This can be seen in the "substation upgrade" section.

Where are we now?

PSE launched the Murden Cove – Winslow “Missing Link” Project and began engaging the Bainbridge Island community in late 2019 on the hybrid solutions package to improve Bainbridge Island’s electric system. A preferred route for the “missing link” project was selected in fall 2021. PSE is working towards completing the necessary fieldwork and engineering, real estate planning, and permitting to continue the design process. PSE is committed to working directly with impacted property owners as we progress. We expect the new transmission line to be in-service in 2025/2026. The project timeline is subject to change and will be kept up-to-date as the project continues.

To understand community values and interests around the new transmission line, so we engaged the community to gather input and feedback.

There were many ways to be involved, which included viewing the Community Sounding Board (CSB) meetings, attending community workshops, and providing input and feedback via comment form 24/7, as well as by email, or phone. 

PSE identified a preferred route for the Murden Cove – Winslow Transmission Line Project and shared it with the community on November 30, 2021.

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Community Sounding Board

We convened the CSB to help inform the routing process for the new “missing link” transmission line between the Winslow and Murden Cove substations. The 18-member CSB individually provided input and feedback on routing criteria, route segments, route options and other project related topics identified by PSE during the transmission line routing process. Members were selected from a pool of applicants and represented a variety of geographic, organizational, and individual interests on Bainbridge Island from inside and outside the project study area.

Community workshops

PSE hosted two workshops where Bainbridge Island community members could provide feedback to inform the routing process. The first workshop held virtually on Jan. 21, 2021 introduced the route segments under consideration and invited initial community impressions and feedback on these segments. Following the first workshop, PSE held a feedback period between Jan. 22 and Feb. 12 to continue collecting community input on route segments and heard feedback from a variety of community members. Feedback was collected through responses to an online interactive Segment Explorer tool, emails, voice messages, online comment forms, and mailed letters. A summary of themes PSE heard during the first feedback period is available in our community workshop materials below.

The second workshop held virtually on May 3 introduced the route options under consideration and provided an opportunity for the public to provide feedback on these potential routes. Between May 4 and June 2, PSE continued collecting feedback on route options through an online interactive Route Explorer tool, email, voice message, and online comment form. 

Information sessions

In response to community interest shared during feedback periods for the “missing link” transmission line project, PSE held two information sessions for the community. One focused on underground transmission lines and the other on electromagnetic fields (EMF).

The first information session on underground transmission lines was held on August 16, 2021. Information provided at the session included the benefits, challenges, and processes involved with underground transmission lines. Attendees were able to submit questions to a panel that included an independent underground transmission line expert and representatives from PSE.

The second information session on EMF was held on September 29, 2021. Information provided at the session include a discussion of what EMF is, where frequencies are found, and how it relates to health. Attendees were able to submit questions to a panel that includes an independent, board-certified health physicist and representatives from PSE.

Bainbridge Island City Council’s recommendations on the routing of the Missing Link

Prior to selecting a route option for the Missing Link, the Bainbridge Island City Council shared a letter with community values and interests that PSE should keep in mind when selecting a preferred route. The City Council delivered their letter of recommendations via email to PSE on October 8. The letter from City Council is available below.

• City Council letter

On November 1, PSE responded to the City Council’s letter. PSE’s response letter and its appendices are available below.

• PSE response letter
• PSE response letter appendices

After more than a year of technical analysis and community engagement, PSE has selected a route option for the "missing link" transmission line. This is an important step towards improving reliability for two-thirds of the island currently at risk of outage due to lack of transmission system redundancy. PSE has worked diligently to understand from a technical perspective which route option best meets the route criteria and project need. Feedback from the Community Sounding Board (CSB) and the community - which we have been gathering since the project launch in 2019 - was considered in the route selection.

• We heard a wide range of input from hundreds of island residents on their values related to route siting. The feedback was varied, and it helped PSE better understand community values and perspectives to inform route selection.
• We appreciate the hundreds of islanders and the dedicated Community Sounding Board members who took the time and made the effort to join us in the siting conversation and share their feedback to inform our selection of the preferred route option.

PSE held an online Community Announcement on November 30, 2021 to share the selected route option with the Bainbridge Island Community.

• Community Announcement presentation slides
• Community Announcement summary

Route Option B, D, E reroute

During technical analysis, PSE identified new residential developments on the east side of the planned State Route 305 (SR 305) crossing from the Murden Cove Substation (Route Segment 18). These developments made this segment of Route Options B, D and E no longer feasible.

PSE re-routed Routes Option B, D, and E to travel south along Sportsman Club Road and approach the SR 305 crossing through existing commercial properties. After SR 305, this route crosses private property before intersecting with Moran Road then following the originally proposed remaining routes for Route Options B, D and E. 

The Missing Link's selected route option

The selected route option – "Route A" – is the best route option based on our siting criteria and balancing the values the community shared to connect Murden Cove and Winslow substations. The selected route option finds balance with a variety of siting considerations including the ability to receive permit approvals, feasible to construct, future maintenance needs, and community values.

Safety is always the foundation of everything PSE does. In comparison to other route options the selected preferred route:

• Is the shortest route
• Includes the fewest parcels, including residential parcels
• Follows public road rights-of-way for the entire length
• Contains land uses and zoning that represent less density
• Has a comparatively lower area of tree canopy
• Has existing overhead distribution lines along its entire length

This provides the best opportunity to minimize impacts on the following community values:

• Trees, wetlands, and habitats
• Private property and residential neighborhoods
• Schools

As part of PSE’s technical analysis and review, we weighed the community’s feedback alongside a variety of considerations, including a thorough review of existing restrictions and regulations, analysis of supplemental wetland delineations, coordination with the City of Bainbridge Island, and technical reviews by engineers, vegetation management, and other technical staff.

PSE has determined that Route A is the best choice for the “missing link” transmission line to improve reliability on the island.

Designing the Missing Link

Now that we have selected a route option – PSE will focus on engineering design and permitting which will allow us to move towards improving the reliability of the transmission system on the island. PSE will soon begin fieldwork in the road rights-of-way to inform engineering. Later in the fieldwork process, we may need to do fieldwork on private property which may be physically impacted by the new line. PSE will work directly with any impacted property owners as the project progresses. We anticipate the new transmission line will be in service in 2025 or 2026.

Photo simulations

Sportsman Club Road North

This simulation is taken from Sportsman Club Road near the entrance of Woodward Middle Schools looking south toward New Brooklyn Road. North Town Woods is located to the left of the image. The new transmission will follow the existing distribution line alignment.

Sportsman Club Road South

PSE heard input regarding the trees located across Sportsman Club Road from the Sportsman’s Club being of significant value. Our technical review determined that it was possible to avoid these trees by locating the transmission line in front of the Sportsman’s Club. In this scenario, PSE would relocate the existing distribution line with the transmission line on the west side of Sportsman Club Road. This would result in the select removal of less significant trees.

High School Road & Fletcher Bay Road

This simulation is taken at a mapped Category II wetland location at High School Road and Fletcher Bay Road. The anticipated vegetation removals would include the trees shown in the foreground.

Fletcher Bay Road

This simulation is taken from Fletcher Bay Road, just north of the Winslow Substation looking to the north. Fletcher Bay Road is where most of the tree removals for this project are anticipated. PSE also anticipates the need to trim trees that extend over the roadway opposite the transmission line.

How to stay informed

There will be additional opportunities for community members to provide feedback on the project to the City when permit applications are submitted and reviewed. We will keep those along the route and the broader community informed as the project progresses. Subscribe to our e-newsletter to receive important project updates.

We expect to begin the permit process in 2022 and anticipate the new transmission line will be in service in 2025 or 2026.