PUD 3’s Belfair Electrical Upgrades Project, beginning at the site of its former warehouse property, is to increase reliability and capacity for the North Mason communities, including the Urban Growth Area (UGA).
PLANNED OUTAGE AUG 5-6: About 7,000 customers, including all of Tahuya Peninsula and most of Belfair, will experience an overnight outage starting at 10 p.m. Wednesday, Aug. 5, until about 6 a.m. Thursday, Aug. 6. This planned outage will allow crews to connect our new Belfair Switching Station to Bonneville Power Administration transmission lines – the culmination of years of work! During the outage, PUD 3 recommends unplugging sensitive appliances and electronic equipment until power has been restored for about 20 minutes. Also, especially with electronics, it is important to use surge protectors.

The Belfair electrical upgrade projects are a priority for PUD 3 to increase resiliency, reliability, and capacity for North Mason customers. The first phase of the project is at the site of the former Belfair Warehouse, adjacent to the current Belfair substation. There, we are building a switching station to upgrade PUD 3’s connection to BPA’s transmission lines and we have upgraded the substation transformer. This work will provide existing customers a more reliable connection to the regional grid. It will also provide future connection points to increase electrical transmission capacity for additional residential and commercial development in the Belfair UGA.
Frequently Asked Questions
Please review Frequently Asked Questions and answers below.
Reliability: The switching station will provide modern protection upgrades to avoid outages impacting thousands of customers on multiple substations when problems occur. With the current technology of the Belfair Substation, when a fault occurs on the transmission side, the only protection is for BPA to drop the feed between Shelton and Bremerton and Mason PUD 3 loses transmission to five substations at once. This causes widespread power outages to over 17,000 customers and greatly delays restoration times.
Capacity: PUD 3 is not able to provide the power to meet the large requests and short timeline development opportunities that have been proposed over the past several years. The lack of electrical capacity continues to be a primary deterrent for companies considering locating to Mason County and the Belfair area. The Belfair Electrical Upgrades Project will open the Belfair manufacturing and industrial area to commercial growth, providing significant economic benefits to all the surrounding communities (including Belfair, Shelton, Grapeview, Allyn, Tahuya peninsula, and more). In recent years, the Economic Development Council (EDC) of Mason County, had to turn away multiple recruitment opportunities due to lack of electrical infrastructure capacity. This resulted in an estimated loss of hundreds of potential new jobs.
BPA Transmission Tap: The project also provides an opportunity to expand access to the Bonneville Power Administration’s (BPA) high voltage transmission system for future load growth in the area. BPA has restricted any future taps along this transmission corridor, so the only way to provide additional capacity for customers is through a new switching station like the one we're constructing in phase one of the Belfair Electrical Upgrades Project.
The Project generally consists of four phases.

Phase 1 – Remove the old Belfair Warehouse (completed in 2024) and construct a switching station on PUD-owned property (construction underway - summer 2026 completion, fall energization). This will include modifying the connection to the high-voltage BPA transmission lines and re-feeding the Belfair Substation and the Union River and Collins Lake Substations out of the new switching station.
Phase 2 - Upgrade the existing Belfair Substation, which is at the end of its useful life, with a larger-capacity transformer (completed July 2025). This will allow for additional growth within its existing service reach, and provide increased resiliency and reliability for the residential, commercial, and industrial growth in the area.
Phase 3 - Construction of a new 3.6-mile 115 kV transmission line from the PUD's new switching station to the site of a future substation near the Belfair Water District's water tower. After evaluating multiple routes, the best plan is to generally follow BPA's transmission corridor and then up along Clifton Ridge to the new substation location (see Phase 4 below). A state CERB loan has been approved for this portion of the project.
Phase 4 - The final phase of this multi-year project will be to construct a new high-capacity substation near the Belfair Water Tower to serve upcoming development in the Log Yard Road area and on land that will be opened by the future WSDOT Belfair Freight Corridor project. This new substation will not only provide for growth, but also allow PUD 3 to re-route power to Belfair and Tahuya in emergency situations if there are issues on the primary transmission line.
The Project will be physically located in/near the Belfair Urban Growth Area.
The first phase will be to construct a switching station at the former PUD 3 Belfair Warehouse (21341 E State Route 3). There will also be a future transmission line from here, generally following the Bonneville Power Administration (BPA) utility corridor along Clifton Ridge, to a future substation location near the Belfair Water District water tower and Log Yard Road.
This project is a significant investment bringing more electrical capacity to serve North Mason County businesses and residents, inclding those in Belfair, Allyn, Victor, and the Tahuya Peninsula.
The total project cost for all phases could be upwards of $16 Million. Most of the specialized equipment needed, and labor to install it, is subject to competitive bid processes. There are many stages to this type of multiyear project, so providing a hard dollar amount in these early stages is challenging.
PUD 3 has been the recipient of several grant awards to help this project move forward:
- Representative Derek Kilmer supported an application that was awarded $3 Million through the Congressional Directed Spending Project.
- The American Rescue Plan Act (ARPA), with Mason County as a conduit, is providing $1.5 Million for the project.
- Thanks to our 35th District legislators, $1 million was allocated from the Washington State capital budget to assist with the project.
- State CERB loan approved for up to $5 million.
PUD will continue to pursue grants and financial assistance for this project to reduce the impact on ratepayers. System Capacity Funds, capital construction bonds, and ultimately electric rates will provide the backstop for project costs that cannot be funded through grant awards.