Flowering quince. Orcas Island, Washington. Photo by: Somelab
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 early 2018. Learn more about the sequence of work, the construction schedule, and what to expect on our interactive construction map.

Denny Substation Construction

In late March Walsh Construction, the Denny Substation contractor, began preparing for substation construction. As part of this construction, Pontius Avenue N. between Denny Way and John Street was permanently closed on April 4. Two adjacent, city-owned parking lots were also permanently closed on April 1.

Denny Network Construction

In April, construction will continue on Minor Avenue between Stewart and Virginia Streets and on Stewart Street between Minor and Westlake Avenues. Current work includes potholing to confirm utility locations, soil sampling for analysis, setting up settlement monitoring stations and installing the large electrical vaults. Night and weekend work is expected.

Traffic Restrictions

During construction on Minor Avenue, northbound traffic between Stewart and Virginia streets will be detoured to Boren Avenue.

From now through August 2016, drivers should expect congestion on Stewart Street between Yale and Westlake Avenues as the project continues with the installation of vaults and duct banks along Stewart Street. 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 week day work hours will be 6 a.m. to 7 p.m.
  • Some night and early morning work will take place between 7 p.m.
    and 5 a.m.
  • Some weekend work will take place from 9 a.m. to 7 p.m.
  • Parking and loading restrictions near work zones
  • Typical construction impacts such as dust, noise and truck activity

Monthly Online Construction Meetings

Join the Denny Network Project team and the project’s contractor, Shimmick Construction, for an online construction update. This web-based event will be held at noon on April 6 and kicks off the first in a monthly series designed to keep project-area stakeholders informed of construction progress. We’ll share an update of completed work, look ahead at what’s next, and answer your questions. Sign-up for the April 6 Online Construction Meeting.

Updated: April 2016

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