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SR 520 - Floating Bridge and Landings Project: Construction Locations

Construction of the SR 520 Floating Bridge and Landings Project will take place in several locations. Assembling the bridge and connecting it to the rest of SR 520 will happen between the west and east shores of Lake Washington in Seattle and Medina.

This is the first construction stage of the I-5 to Medina: Bridge Replacement and HOV Project.

Project location map showing SR 520 between Seattle and Medina.

Construction locations

Construction activites for the new SR 520 floating bridge will take place in four locations throughout the state.  

We'll float the largest pontoons from Grays Harbor to Lake Washington.

The largest pontoons will be towed from Grays Harbor to Lake Washington.

These pontoons are already under construction in Aberdeen (A) as part of a separate contract and will be stored in Grays Harbor until needed.


As shown in the map below, we are also building 44 stability pontoons in Tacoma (B) and bridge anchors and hundreds of precast deck panels in Kenmore (C).

All of these components will be floated to and assembled on Lake Washington (D) to form the new SR 520 floating bridge.