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Seattle City Light DEBRA SMITH, General Manager and CEO
Denny Substation Project
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Construction [Denny Substation]

The Denny Substation is located in South Lake Union at Denny Way near Stewart Street. Construction began in late May 2016, and the substation will be in service (energized) in mid-2018, with limited construction continuing into late 2018. Follow along on the interactive construction map.

In late March 2016, the Denny Substation contractor (Walsh Construction) began preparing for substation construction. As part of this preparation, Pontius Avenue N between Denny Way and John Street was permanently closed, along with two city-owned parking lots adjacent to the substation site.

Throughout 2016, crews relocated utilities in the right-of-way to make room for vault and duct bank installation. They also drilled shafts and poured foundation columns inside the substation site. In late 2016, the outer walls began to take shape as crews installed structural steel on the east side of the site. In 2017, crews completed structural steel installation, made progress on the elevated walkways, constructed all equipment buildings, installed electrical equipment and completed installation of most of the substation's siding.

In early 2018, crews tied the substation into an underground transmission line, installed a large stormwater detention vault and continued working on siding installation. They also began a four-month process to complete duct bank installation in John Street. As we near energization sometime in mid-2018, crews will test equipment, complete the elevated walkway and build out the community spaces in the southeast and southwest corners of the substation. Final activities throughout the spring and summer of 2018 will include street and sidewalk restoration, construction of the off-leash area and art installation.

Visit the Denny Substation Design to view more project renderings.
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