Tacoma Power is planning to replace the 19 aging lattice towers on and near North 21st Street with 12 steel monopoles on every other block. Construction is scheduled to start in April 2018. As part of the project, Cushman Substation will be disconnected from the electrical system, and equipment in its fenced yard will be removed. The building will remain untouched by the project. Decisions about the building’s future have not yet been made.
The City of Tacoma would like to update N. 21st Street to current design standards that include sidewalks, turn lanes and bike lanes.
What is happening to the old power towers in the median of N. 21st Street in Tacoma?
Tacoma Power will tear down the bulky, rusty lattice towers on the otherwise picturesque 1.25 miles between N. Highland and N. Adams and replace them with sleek, galvanized steel poles.
Why do the towers need to come down?
The lattice towers are over 90 years old and in a state of significant deterioration.
How many towers are there now, and how many will there be when the project is complete?
There are now 19 total towers: one on every block of North 21st from North Adams to North Highland (total of 15); two in nearby Westgate Center; one near Cushman Substation; and one in front of Pearl Substation on Pearl Street. Those towers are about 75 feet tall.
They will be replaced with 12 galvanized steel monopole towers: one every other block of North 21st Street (total of nine); two in Westgate Center; and one at Pearl Substation. The new towers range from 100 to 110 feet tall.
In addition, some of the wooden poles that line the sides of 21st Street from Puget Sound Avenue to Proctor will be replaced with taller wood poles.
Are there other components to the project?
Yes. The tower replacement is part of the Pearl/Cushman Upgrade project, which includes improvement to how the circuit breakers will work for the transmission lines that connect three large substations throughout Tacoma (Pearl, Cedar and Hilltop substations).
What will happen to the Cushman Substation?
In the fall of 2016, some of the substation’s features will be turned off, but it will still be an energized substation. In the fall of 2017, it will be disconnected from the electrical system and no longer an energized substation. At the end of 2017, the equipment and structures within the fence will be removed. The classic substation building will remain, although no other decisions about the building’s future have been made.
Will there be traffic improvements to N. 21st Street as part of this project?
Tacoma Power is working closely with the City of Tacoma’s Public Works Department to integrate the new pole locations into its design for potential traffic improvements to N. 21st. (The City of Tacoma does not yet have funding to complete roadway improvements.)
The power pole work is independent of significant traffic improvements and would happen in advance of any changes to the road.
For more information on the traffic improvements, please visit the City of Tacoma's website.
What is the history of the towers?
The towers are part of the Potlatch Transmission Line, which was originally built in 1925 to bring power from the Cushman Hydroelectric Project to Tacoma. Other than a few structures at the hydroelectric project, the lines on N. 21st will be among the last of the original transmission line structures to be replaced. Tacoma Power replaced the Narrows lines in 2006 and North Bay lines in 2014; the Henderson Bay towers at Purdy will be replaced in 2018.
What is the project schedule?
- Design and permitting: Ongoing through 2016.
- Cushman Substation: The substation will be deactivated in the fall of 2016, which means some of its automated functionality will be turned off, but it will still be an energized, functioning component of the utility’s power system. The equipment and structures within Cushman Substation fence will be removed at the end of 2017.
- Construction on N. 21st Street is targeted to start during the spring or summer of 2018.
- The project is scheduled to be complete in early 2019.
What is the project cost?
The estimated project cost is $8 million.
Why are the lines going overhead instead of underground?
Transmission lines are not typically placed underground because of the significant increase in cost. In this case, the cost would be five to 10 times more than overhead lines.
For more information, contact Nora Doyle at (253) 502-8117 or firstname.lastname@example.org.