Agenda for Shoreline council Monday - staff report for Study Item 9(a) is now available

The agenda for Monday's Shoreline council meeting is here. At the time of publication, the staff documents for Study Item 9(a) were not available.

Study Item 9(a)
Discussion of Required Undergrounding in the South Shoreline/148th Street Light Rail Station Area and the Impact on the Sound Transit Project

Seattle City Light (SCL) currently has three-phase (3-phase) underground power running down 5th Ave NE, in front of the future Shoreline South/148th Light Rail Station. This underground power is what is called “direct bury” power, in that the powerlines are not installed in any conduit (typically plastic piping), but rather are buried directly in the ground as was the typical practice in past years.

The issue with direct bury lines is that they degrade over time due to exposure to the elements and the difficulty in replacing the lines as the lines must be dug up rather than being “pulled” like those in conduit. All current underground electrical lines are constructed in conduit for these reasons.

Constructing new connections to this existing direct buried line is not viable for most development, including the Lynnwood Link Extension (LLE) Project, due to its age and the inability to replace or upgrade the cables without digging it up. Given that the 5th Ave NE 3-phase line has reached the end of its useful life and is in danger of failing, SCL has planned for its replacement with new 3-phase power in a duct bank project (multiple conduits put together) within 5th Ave.

However, in early 2021, SCL informed Sound Transit and the City that it does not have the capital funding to complete the Duct Bank Project in coordination with the LLE Project timeline.

This will be a discussion of “what do we do now?” See the staff report to review the options under consideration.

--Pam Cross