Skagit River Hydroelectric Project at Diablo Lake. Photo by Roman Khomlyak,
Seattle City Light LARRY WEIS, General Manager and CEO
Denny Substation Project
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Denny Substation Project Update

Project Status

Seattle City Light is constructing a new electrical substation (Denny Substation) and an underground distribution network (Denny Network) to accomplish a major electrical system upgrade for the city of Seattle.

Construction of the network, which is being installed underground in the South Lake Union and Denny Triangle neighborhoods, began in late February 2016. This work is anticipated to be complete in mid-2018. Learn more about the sequence of work, the construction schedule, and what to expect on our interactive construction map.

Denny Substation Construction

Throughout May, crews will continue preparing for shoring wall installation and will begin demolishing the paved surfaces inside the construction fencing. An electrical vault will be installed on John Street just east of Minor Avenue N. Installation of a new sewer and water line will also begin on John Street. Construction will begin on John Street near Minor Avenue N. and progress east to Yale Avenue N. All work will be conducted between 7 a.m. and 5 p.m.

Denny Network Construction

Throughout May, construction will continue on Minor Avenue between Stewart and Virginia Streets and on Stewart Street between Minor and 6th Avenue. Duct banks will be installed along Stewart between Boren and Minor avenues and from 9th to Terry avenues. Crews will also continue potholing to confirm utility locations, retrieving soil sampling for analysis, setting up settlement monitoring stations on local utilities, and installing the large electrical vaults along Virginia. Night and weekend work is expected due to coordination with other City events.

Traffic Restrictions

From now through August 2016, drivers should expect congestion on Stewart Street between Yale and Westlake avenues as the project continues installing key infrastructure. To stay informed about traffic conditions, subscribe to SDOT's e-mail alerts.

What to Expect During Construction

  • Lane restrictions and some traffic and pedestrian detours
  • Typical weekday work hours will be from 7 a.m. to 7 p.m.
  • Some night and early morning work will take place between 7 p.m.
    and 5 a.m.
  • Some day and night shift weekend work
  • Parking and loading restrictions near work zones
  • Typical construction impacts such as dust, noise and truck activity

Monthly Online Construction Meetings

With construction of the Denny Network having begun in February 2016, the project team remains committed to providing the public with regular and reliable information about construction. Together with the contractor, the team is hosting a monthly online construction update. The previous meeting covered details on current and upcoming work, a lesson on vault and duct bank installation, and how the crews are staying safe on the job. Listen to the recording! Please note that you may be prompted to register, but only your first name is required (your email address is not required).

Updated: May 2016

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    P.O. Box 34023
    Seattle, WA 98124-4023

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