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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 19, 2017


Construction activities continue near SR 520

Due to the volume of construction activities taking place near the new West Approach Bridge North, boaters should be vigilant and navigate with care. Using appropriate boater etiquette and following speed limits near construction activities will keep both boaters and construction crews safe.

The east and west navigation channels are currently open, but may 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). Please note that one navigation channel will always be open and accessible to boaters. 

To receive updates about upcoming blockages of the navigation channels, email us.

open navigation channels map
Navigation changes on Lake Washington at SR 520. Click image for printable version (pdf 323 KB). 


Opening Day - May 2017: Important restrictions to note for boaters, pedestrians and neighbors participating in opening day activities.

This year, both the West Approach Bridge North Project (WABN) and Floating Bridge and Landings Project (FB&L) have construction equipment and large structures on Lake Washington. While you are enjoying opening day activities on Saturday, May 6, please stay at least 150 feet away from all construction areas for your own safety.

See below for a map that shows the best route for kayakers and canoers around construction and shows the navigation channels for larger boats. The map also shows restricted parking access that you may have used in previous years for opening day. These parking areas are now construction staging areas and are not publicly accessible. If you have any questions on opening day about navigating around construction, please call our 24-hour hotline – (206) 708-4657.

boater map
Click image for printable version. (pdf 77 kb)

Safety precautions

While all of the pontoons and much of the other marine equipment has been removed from the lake, mariners should continue to maintain a safe distance and minimize wake around all floating derrick (crane) barges and other construction vessels within the SR 520 project area.

Mariners are advised to use caution while transiting near derrick barges and work barges within the SR520 project area. These vessels are currently anchored and may present submerged hazards. Work zones around some derrick barges have been marked with red/white buoy strings. Mariners should maintain a safe distance and minimize wake around all floating derrick barges and other construction vessels.

East navigation channel clearance under the new SR 520 floating bridge

At the east navigation channel, boaters will see two signs indicating clearance. Both signs are gauges posted at the water level to show the clearance for boaters at the current water level. The graphic below shows the east navigation channel clearance under the new SR 520 floating bridge.

The only sign currently posted on the bridge is on the pontoon located at the west side of the channel. While this sign is a gauge, as shown below, this sign will always show a clearance of 70 feet at water level since the pontoon rises and falls with changes in water levels on Lake Washington.

A sign will be posted on the fixed, east approach column at the east side of the channel. The clearance is 65 feet at the east end of the channel so boaters will see that portion of the sign at water level. As water levels lower, the clearance on the east side of the channel may rise up to approximately 67 feet. 

East navigation channel gauges

East navigation channel height of the new SR 520 floating bridge. Click on the image above for a larger, printable version (pdf 6.3 mb).


Nautical mile markers

The new SR 520 floating bridge has nautical mile markers to indicate distance for boaters on Lake Washington. The markers are placed on both the north and south side of the bridge. The graphic linked below shows the layout for the nautical mile markers.

Nautical Mile Marker
Click on the image above for a larger, printable version (pdf 4.16 mb).