Work underway on Girdwood to Indian power line

By Chase Berenson

TNews Contributor

Chugach Electric is anticipating 45-60 days of traffic control on the Seward Highway this May, June, and August to replace a transmission line between Girdwood to Indian, according to a March 12 presentation in Indian.

The 11-mile Girdwood to Indian section runs along the Seward Highway and is part of a 90.4 mile line running from Cooper Landing to Anchorage.  

This line was built 62 years ago and is reaching its end of life. 

Chugach has been replacing the line in sections. Thirty-six miles of the line and five sections have already been replaced. Once completed, this sixth piece of critical infrastructure will ensure reliability between hydroelectric plants on the Kenai Peninsula and power plants in the Anchorage area, according to a Chugach Electric spokesman.

The two primary presenters at the public meeting were Mike Miller of Chugach Electric and Jason Hodges of Northern Powerline Constructors (NPC), the project’s construction company.  

The Quartz Creek Transmission Line, showing areas already completed, the Girdwood to Indian area, and future areas of work. (Photo courtesy of GirdwoodtoIndianRebuild.com)

They told 16 audience members that there will be only one planned outage to customers along the Turnagain Arm lasting 2-3 hours next year, there will be some travel disruptions on the Seward Highway this summer, and that safety is their top concern through the project. Work began earlier this month and is scheduled to conclude in April 2025.

Because the transmission line is fed by power sources to the north in the Anchorage area and the south on the Kenai, the flow of power into the Turnagain Arm communities largely won’t be directly impacted while the line is being replaced, presenters said. Girdwood, meanwhile, will still receive power from the south while Bird Creek and Indian will still receive power from the north.

The 11-mile segment of the line between Girdwood and Indian has been divided into six sections, according to Hodges and Miller's presentation. The first two sections are expected in the area from Indian to where the lines cross the Seward Highway. Section 3 is through the avalanche chutes north of Bird Point. Section   4 is from the end of the avalanche chutes until where the lines cross the Seward Highway again. Section 5 runs alongside the edge of the Turnagain Arm. And Section 6 is the final section coming into Girdwood.

Work has begun in Sections 1 and 2 and will continue through July, they said.

Chugach is preparing anchors for new structures and poles to be installed, and, starting in May, NPC will begin assembling the new structures in the Bird Creek overflow parking lot at mile 95.7 of the Seward Highway.  Once the structures have been built, a Chinook helicopter will be used to transport the structures into their new homes in June and then a clean-up crew will remove debris in July, according to the presentation.

Work in Section 3 will be performed next winter once the ground and surface waters are frozen, and a snow/ice road will be constructed to reach the work areas.  

Because this area is in the avalanche chutes, Chugach has taken special care to prepare its infrastructure in the unlikely event that a significant avalanche can reach far enough to impact them. Miller said.  

Support structures holding the transmission line are built strong enough to withstand the snow, while the line itself is designed to break away, Hodges and Miller said. This means that should an avalanche occur, there is no anticipated repair work needed to the steel structures and the Chugach line crew can focus on quickly reinstalling the transmission line. However, this would only be in case of an extreme avalanche, which hasn’t happened in this area in the past 10-15 years, the spokesmen said.

They said Section 4 will follow the same schedule and work type as sections 1 and 2.

Section 5 is the real challenge, according to the presentation, where the transmission line travels along the edge of the Turnagain Arm.  

The current latticework support structures are not all located on sufficient foundations, so there will be civil engineering work to expand and construct foundation pads, according to Hodges and Miller.

Map of the six sections of the Girdwood to Indian transmission line replacement. (Photo courtesy of GirdwoodtoIndianRebuild.com)

The current pads are not all easily accessible by Chugach crews, they said, resulting in trucks parking along the side of the highway and crews climbing the rocks to reach them when maintenance is necessary.  

Additionally, some of the structures are built so low that they are directly impacted by the tidal action of the Arm, they said. The new foundations will be safer for crews and highway users by allowing trucks to approach directly to the pad, and they will be built to keep them away from the water at even the highest tides.  

However, this work will require crews to remove the Seward Highway guardrail in 14 locations, and Chugach is working with the Alaska DOT on traffic control, lane closures, and travel disruptions, Hodges and Miller said. 

Construction will be suspended in July due to the high levels of highway use in the middle of the summer, they said.

Once this work is complete, the latticework structures will be replaced with tubular structures that should have less visual impact on the beautiful area while driving the Highway or recreating on the Bird to Gird Pathway.

Section 6 is the final section into Girdwood, and that work will also occur in January to March 2025.  Working in the winter allows the team to minimize impacts on wetlands and other areas when the ground is frozen.  The only scheduled outage of the project will occur at the end of Section 6’s work when they are connecting the line to the Girdwood substation, and this outage should only last two to three hours, according to planners.

Once it is completed this project will help to ensure redundant power access for the Kenai Peninsula and the Anchorage area by allowing power to flow through the transmission lines.  

Hodges and Miller said the project will include a fiber optic cable strung across the lines for Chugach’s communication, which will be far superior to the current microwave communications system and will allow Chugach to respond to and correct outages faster in the future.

NPC has project offices in Bird Creek behind the Essential One gas station and in Girdwood on Old West Street.  Planners said the public can learn more about the project by visiting www.GirdwoodToIndianRebuild.com or by stopping by one of the project offices when staff is present.