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SR 520 - New Floating Bridge and Landings: Contractor Information

WSDOT awarded the Floating Bridge and Landings Contract to Kiewit/General/Manson, A Joint Venture (KGM)


Contractor quick facts

Contract amount: $586.6 million

Upset price: $750 million

Construction begins on Lake Washington: 2012

Expected to open to traffic: spring 2016

Contact information:
Kiewit/General/Manson,
A Joint Venture
3015 112th Ave. NE, Suite 100
Bellevue, WA 98004
Phone: 425-576-7100
Fax: 425-576-7159

KGM will complete the following work:

  • Building a six-lane floating bridge with wider, safer shoulders, a transit/HOV lane in each direction and a bicycle/pedestrian path.
  • Towing concrete pontoons from Grays Harbor and assembling the floating bridge on Lake Washington.
  • Building 44 supplemental concrete pontoons and 58 anchors.
  • Building an east approach connection to the six-lane Eastside highway currently under construction and building a new maintenance facility and dock on the east shore of Lake Washington.

KGM had the best combination of bid price and technical score. By combining design and construction in one contract at a fixed price, the contractor team has more opportunities for innovation while also controlling costs for taxpayers.

KGM combines the experience of three accomplished construction firms. Combined, KGM has a proven track record of safely delivering world-class projects on-time and on-budget, including a number of bridges in the region.

KGM has assembled the workforce and hired vendors and sub-contractors. Visit the SR 520 Contracting and Job Information page for additional information about SR 520 program job and contracting opportunities.

Funding for the project was allocated by the Washington State Legislature using a combination of state and federal funding and future SR 520 toll revenue. Visit the SR 520 Program Costs, Funding and Tolling page for more information.


West Connection Bridge project awarded to Mowat-American Joint Venture


Contractor quick facts

Contract amount: $22.1 million 

Construction began on Lake Washington: Summer 2013 

Contract date for project completion: Late summer 2014 

Contact information: 
SR 520 Bridge Replacement and
HOV Program
999 3rd Avenue, Suite 900 
Seattle, WA 98104 
Phone: 206-770-3500 
Construction hotline: 206-708-4657

Mowat-American completed the following work:

  • Construction of a 1,330-foot-long bridge connecting the west end of the new floating bridge (Pier 36) to the existing west approach.
  • Widening five spans of the existing west approach bridge and constructing six new spans.
  • Six existing piers have been widened and five stand-alone piers have been built for a total of eleven new piers. These piers are supported with a total of 19 columns.
  • The WCB will carry four lanes of traffic: two westbound lanes and two eastbound lanes.  The lanes will be 11 feet wide with 2-foot-wide left-side and right-side shoulders in both directions. It will match the total width of the existing west approach bridge.

The West Connection Bridge contract was awarded through a competitive bidding process. Mowat-American’s bid was lowest among four firms that competed for the job. 

Funding for the project was allocated by the Washington State Legislature using a combination of state and federal funding and future SR 520 toll revenue. Visit the SR 520 Program Costs, Funding and Tolling page for more information.