Metro – Sunset Transmission Line Project
Avista is committed to making sure your power is safe and reliable, which includes upgrading and replacing equipment when needed. Our transmission line that runs from the Sunset Substation below High Drive Bluff to the heart of downtown Spokane is slated for replacement. This is vital infrastructure that is critical to meeting our community’s ongoing needs.
This approximately two-mile line goes through publicly accessed trails and City of Spokane park property and includes upgrading 13 transmission structures from wood to steel. The substations on either end of the line, Sunset Substation below the bluff and Metro Substation in downtown, are being rebuilt to serve growth in the region. The line between them needs upgrading too. Construction is planned to begin in late August 2023 and take approximately two months.
- See map
- Clearing and Grading Plans – Access Plans (pages 1-14) – updated May 2023 after considering community input
- Restoration Plans (pages 15-26) – updated May 2023 after considering community input
Why rebuild?
- Upgrade aging structures - 50 years old
- Expand electrical capacity
- Enhance wildfire resiliency by moving from wood to steel poles
- Deliver safe and reliable power
Engagement
During the first few months of 2023, Avista reached out to neighborhood councils, Friends of the Bluff, and neighborhood residents in the vicinity of the Bluff to learn more about what the community wanted to see from this project. We extended our original comment period by an additional four weeks (to March 17) to help ensure everyone had a chance to provide input.
Avista appreciates the feedback we’ve received and want to do the best job we can to balance the needs of the project with the desires of key stakeholders, including trail users and those who live near the transmission line. Based on input, we are making some key changes to our project approach. To learn more, please see the FAQs and Project Updates below.
Q. What changes have you made with your approach to this project, based on community feedback?
A. Avista appreciates the feedback we’ve received about this project over the past three months. We want to do the best job we can balancing the needs of the project with the desires of key stakeholders, including trail users and those who live near the transmission line. Based on input, we have made some key changes to our project approach, including the goal to minimize ground disturbance by proceeding with the softest, lightest touch possible. These key changes include:
- We identified three structures (2/4, 2/5, 2/6) where crews could helicopter in the new poles. We can’t utilize this approach with every structure given the proximity to homes.
- We are also proposing using tracked vehicles to minimize vegetation impacts with limited road construction
- We are decreasing the number of construction pads used during the project
- We are planning to install gates and/or boulders to prevent motorized vehicle access
The goal will be to restore the site to pre-work condition and not leave access roads or pads. Avista is in the process of revising our plans and expects to have new plans posted to our project website by June 1.
Q. When will construction take place?
A. Construction is planned for Fall 2023 and will take about two months to complete. Although we do not yet have a contractor on board, we anticipate work will begin during toward the end of August.
Q. How will you communicate about trail closures and re-openings during construction?
A. We have a number of communication channels we are planning to use during construction including frequent updates to our project website, emails to interested stakeholders (sign up at BluffProject@avistacorp.com), and coordination with City Parks and Friends of the Bluff to push out updates through their channels. We also plan to post signage at trail access points, as well as along the trails. Our goal is to keep trails open outside construction windows when it is safe to do so.
Q. What will you do to prevent motorized vehicles from accessing the bluff using your construction roads?
A. We heard a number of concerns about this issue during the comment period. Avista will work with our contractor to place temporary barriers such as boulders to prevent motorized vehicle access during construction. Following construction and restoration, we are planning to install gates at access points to allow only authorized access by fire and utility personnel, as needed.
Q. The restoration plans posted on your website are fairly vague. When will you have plans that are more detailed and complete?
A. Based on feedback, we are in the process of revising our restoration plans. A more detailed set of plans is expected to be posted to our project website by June 1, 2023.
Q. Will you be replacing the trees that will be removed for this project?
A. Avista will discuss the requirement for tree replacement with City of Spokane Parks forester. Tree replacement may not occur within the project impact area; however, it will occur in areas of the bluff with a greater need for tree cover.
Q. How do you plan to prevent the spread of noxious weeds like Scotch Broom?
A. Avista is currently working with a Washington State licensed herbicide applicator to target noxious weeks along the corridor. Prior to construction, Avista will clearly mark the Scotch Broom infestation areas so crews can avoid disturbance in those areas. Noxious weed control will occur before and after construction.
Q. Why don’t you use helicopters for this project, like you did a few years ago?
A. Based on community feedback, we took another look at our approach and identified three structures (2/4, 2/5, 2/6) where crews could helicopter in the new poles. We can’t utilize this approach with every structure given the proximity to homes, which would need to be evacuated according to safety regulations.
Q. Why don’t you put the transmission line underground?
A. Underground transmission lines are extremely rare. Not only do they operate with less capacity (transmission lines heat up and when they are underground, there is no way to cool so they lose capacity), but more importantly, they are less resilient (any sort of fault or equipment failure takes much longer to repair, resulting in huge service disruptions and highly invasive environmental impacts). Avista does not have the expertise to repair underground transmission lines and therefore would have to rely on highly specialized contractors, which would likely mean a service interruption of up to 30 days or longer. This system vulnerability is simply not acceptable to Avista. This means that going underground with transmission is typically not an option.
An additional consideration for the Bluff is the significant environmental impact. To install underground transmission lines would mean large excavation areas as well as the need to install roads and landing pads for concrete truck access.
The cost to underground transmission lines is extremely expensive. On average, overhead 115kV transmission lines are approximately $500,000 per mile. To underground this in rural areas or those with conditions that would accommodate undergrounding, the cost is 10 times or approximately $5 million per mile. For urban or basalt-type area undergrounding, the cost is 20 times or approximately $10 million per mile. These costs would be borne by all Avista customers through increased rates.
Q. But haven’t I heard of Avista undergrounding lines before?
A. You have likely heard about undergrounding distribution lines, which are the lines that connect power directly to homes and businesses. Transmission carries bulk electricity at higher voltages, while distribution lines operate at much lower voltages. Avista’s current operational standard is to install underground distribution lines for new developments unless the ground conditions make the costs unreasonable.
Project Updates
Avista has engaged key stakeholders to collect feedback and comments about this project for nearly two months. In the final days of the informal comment period (ending Feb 17) we began to hear from Bluff users who were just becoming aware of the project and the opportunity to comment. We want to make sure everyone has a chance to provide input and decided to extend the comment period to March 17. We will respond to individual questions and comments after the comment period closes.
Avista appreciates the feedback we’ve received thus far about this project. We want to do the best job we can balancing the needs of the project with the desires of key stakeholders, including trail users and those who live near the transmission line. Based on input, our goal is to minimize disturbance by proceeding with the softest, lightest touch possible.
While we are still in the process of gathering public feedback, from what we’ve heard so far, we have made some key changes to our plans to minimize disturbance:
- We identified three structures (2/4, 2/5, 2/6) where crews could helicopter in the new poles. We can’t utilize this approach with every structure given the proximity to homes.
- We are also proposing using tracked vehicles to minimize vegetation impacts with limited road construction
- We are decreasing the number of construction pads used during the project
- We are planning to install gates and/or boulders to prevent motorized vehicle access
The goal will be to restore the site to pre-work condition and not leave access roads or pads.
The process is ongoing, and we have not decided on a final plan. We are continuing to work with the City of Spokane and key stakeholders to determine how best to move forward.
We value our partnerships with the City of Spokane, our customers, neighborhood councils, trail users and other stakeholders. This is an important part of the process, and we are grateful to everyone who has taken the time to give feedback.
Avista is committed to providing safe and reliable power, which means maintaining and upgrading our infrastructure when needed. And we are committed to finding reasonable solutions that allow us to do just that while also protecting the natural area and public uses of the Bluff. We believe this approach is consistent with City Park’s management of this property for informal trail use in a more natural setting.
If you are interested in receiving periodic email project updates, please send your name and email to BluffProject@avistacorp.com.
More Information
To learn more about this project, please contact:- Melanie Rose, Regional Business Manager, at melanie.rose@avistacorp.com
- Aaron Tremayne, Transmission Engineer, at aaron.tremayne@avistacorp.com
Check back here for updates and additional engagement opportunities.