Those two maps – top one between the South and Delridge substations, second one between the Delridge and Duwamish substations – show the routes for a fiberoptic-cable project Seattle City Light just announced:

Seattle City Light crews plan to install new fiberoptic cables between several utility substations in the southwest Seattle area. This work is needed to provide reliable communications for City Light’s electrical substations and operations network.

Beginning in mid-July 2020, City Light crews will pull overhead cables along several routes between the utility’s Delridge, Duwamish and South substations. Crews will be working on several utility poles to complete this work.

Additional Details:

Customers can anticipate temporary parking, sidewalk and traffic restrictions during this project. —

Flaggers will assist with directing traffic through work zones.

During this project, City Light will have the opportunity to upgrade infrastructure and replace utility poles that are in poor condition. Additional poles may be installed as well.

Some noise is expected from construction activities.

Maintenance power outages are not expected. If outages are needed, customers will be notified in advance.

The project will require rolling slowdowns on State Route (SR) 99 and SR 509. Details about this phase of work, tentatively beginning in September, will be shared with customers once a construction schedule has been determined.

This project is anticipated to start in mid-July 2020. Construction will last approximately two to three months. Construction work hours are from Mondays to Fridays, 7 a.m.-5 p.m. and weekends from 8 a.m.-5 p.m. Crews may be working outside these hours, as needed.