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SR 520 - Floating Bridge and Landings Project: Boater Information

Key resources for drivers and boaters

SR 520 Bridge Information page

More info on WSDOT movable bridges

Updated: May 26, 2016 

Intermittent construction activities continue near SR 520 navigation channels

The east and west navigation channels will be periodically blocked for critical construction activities. During these blockages, marine vessels should plan to navigate through the unaffected channel (see below for navigational height restrictions).

East Navigation Channel intermittently blocked through June 11 

Through Saturday, June 11, the east navigation channel will be intermittently closed to all marine traffic. The east navigation channel is scheduled to reopen the night of Thursday, May 26 for Memorial Day weekend.

Boats with a navigational height of less than 43 feet can continue to use the west navigational channel. See Section C in the graphic below. 

In mid- to late summer, crews working for WSDOT on the FB&L project plan to open the east navigation channel at its permanent height clearance of 70 feet.

West navigation channel temporarily, partially blocked through June 30 

Through Thursday, June 30, the west navigation channel will be intermittently, temporarily, partially blocked by a flat deck spud barge.

During this partial blockage, the west navigation channel is open with a slightly narrower navigational width. If your vessel requires additional clearance, contact tugboat Big Eagle on VHF-FM Ch. 16 to shift the barge out of the channel. See Section A in the graphic below.  

Click image for printable version.  (pdf 178 kb)  


Navigation channel calendar

Click image for printable version. (pdf 205 kb)

Important restrictions to note (boats over 58 feet tall)

Vessels more than 58 feet tall will not be able to navigate beyond SR 520 until the existing bridge is removed from Lake Washington, currently planned for late 2016. The new floating bridge will not have a drawspan, but the east navigation channel will be 70 feet tall, the same as the I-90 East Channel Bridge.

SR 520 drawspan closed, east navigation channel open

On the morning of Tuesday, Feb. 17 , construction activities for the new floating bridge permanently blocked the drawspan on the existing SR 520 floating bridge.  

At the same time, the  east navigation channel was reopened , allowing boats up to 58 feet tall to navigate around both the existing floating bridge and construction for the new floating bridge. Except for in the case of any construction closures noted above, the west navigation channel remains open to vessels up to 45 feet tall. (pdf 954 kb) 
Boaters, email us  to stay informed.

Have questions? Please read through our drawspan obstruction common questions and answers document  to learn more. 

SR 520 navigation channel restrictions

An exclusion zone is also active immediately north and south of the western-most pontoon. This off-limits zone is marked by six white buoys and a sign on each end of the pontoon. Please note, the white buoys represent the locations of the anchor lines and it is dangerous to pass between the sign and the buoys.

The east navigation channel under the SR 520 bridge is currently operating with reduced clearance. Navigational clearances are higher on the east side of the channel, but obstructions north of the channel reduce the navigational height to 58 feet. Boats taller than 58 feet should not attempt to navigate through the channel.

If your vessel, mast or other aerial equipment is over 58 feet tall and cannot be lowered please do not attempt to navigate around the floating bridge.

Also, please note that the U.S. Coast Guard has established a temporary safety zone around the east span of the SR 520 floating bridge through the end of December 2015. During this time, boaters are prohibited from entering all waters within 100 yards of the east span, unless within the navigation channel. This zone is in place to protect boaters and bridge crews while construction barges are located in the navigation channel under the east span of the bridge.  

What do drivers need to know ?

On Tuesday, Feb. 17, newly placed pontoons obstructed the drawspan of the existing bridge, permanently blocking marine passage through the bridge opening. While openings will no longer occur for marine traffic, crews will still need to open the drawspan for monthly, late-night maintenance work. High winds may also require an opening to relieve stress on the existing bridge.