The Fremont Siphon replacement will detour the Burke-Gilman Trail starting July 6.  You should expect:

  • Work from 7 a.m. – 6 p.m. on weekdays
  • Burke-Gilman Trail detour at project site in effect at all times
  • Construction equipment and vehicles crossing the Burke-Gilman Trail
  • Flaggers and signs to direct trail traffic to detour path
  • Crews and equipment on and around the Fremont project site
  • Fencing and no public access to Fremont Trail Park south of the Fremont project site
  • Increased noise and activity near the Fremont project site
  • No work at either site on Friday, July 3

More information below:


 Project Update July 1, 2015

 Burke-Gilman Trail detour begins week of July 6

Hello from King County –

King County’s contractor for the Fremont Siphon Replacement Project finished building the watertight ring around the tunnel launch shaft at the Fremont site. The ring will control groundwater to protect against settlement of nearby buildings, streets and utilities when the tunnel shaft is dug. Crews will begin digging out the shaft next week.

The contractor will also begin work to move a City of Seattle Combined Sewer Overflow drain pipe during the week of Monday July 6. To allow safe passage around the project site, the Burke-Gilman Trail will be detoured on to a temporary paved path, just north of the existing trail (see map below). The detour will be in effect through mid-August.

Construction equipment such as backhoes and dump trucks will occasionally cross the trail to the work area between the Ship Canal and Burke-Gilman Trail. Flaggers will direct trail traffic near the project area to keep trail traffic away from construction equipment working in the trail. Brief delays may occur. The detour route responds to community requests that trail traffic not be detoured to nearby streets.

Part of Fremont Canal Park south of the Fremont project site will be fenced and closed to the public during this phase of the project.


Slow down! For the safety of all trail users and construction crews, please slow down when approaching the site and follow the direction of signage and flaggers.

Find out more on the web or by contacting the 24-hour project information line: 206-205-5428.Accessible formats available upon request – 206-477-5371 or TTY 711