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SR 520 - Floating Bridge and Landings: Drawspan Information

Key resources for drivers and boaters

Sign up for text message or email alerts for drawspan openings.

Quick reference guide (pdf 360 kb) to drawspan opening times.

To request an opening of the SR 520 drawspan for vessels over 45 feet tall, call 206-440-4490.

The SR 520 Bridge Information page lists scheduled SR 520 drawspan openings.

More info on WSDOT movable bridges

SR 520 marine information

Updated: Jan. 14, 2015

Visit the SR 520 Bridge Information Web page for currently scheduled drawspan openings. 


Upcoming changes to the SR 520 drawspan

As early as Feb. 14, 2015, construction activities for the new floating bridge will completely block the drawspan on the existing SR 520 floating bridge. Note that this date is the earliest that the drawspan will be closed. This date may change due to weather-dependent activities and the dynamic nature of construction.

When the drawspan is blocked, boat traffic will no longer be able to use the drawspan to navigate around the SR 520 floating bridge.
The graphic below illustrates the changes to navigation around SR 520 that will be in place beginning in 2015 through late 2016. (pdf 200 kb)

  • Early 2015: Drawspan blocked
    The east navigation channel will be cleared allowing boats up to 58 feet tall to navigate freely around both the existing floating bridge and construction for the new floating bridge.
  • Mid-2015: New pontoons installed at west end
    The west navigation channel will shift slightly west, to its permanent location. See Section A in the graphic. (pdf 200 kb)

The contractor expects approximately five short-term closures of the navigation channels for construction activities between early 2015 and late 2016. Only one channel will be closed at a time and notifications will be sent out ahead of each closure.

Boaters, email us to stay informed.

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

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.

Drivers and transit riders

Early in 2015 there will no longer be delays related to boater-requested drawspan openings. Although drawspan openings will no longer occur for marine traffic, bridge openings for high winds may occasionally be needed and monthly, late-night maintenance openings will continue.

Click image for printable version.
 (pdf 200 kb)
Representation of nav channel configuration after the drawspan is obstructed.

SR 520 Navigation Channel Restrictions

Beginning in April 2014, the western-most pontoon was moored in its permanent location, 50 feet north of the existing bridge near Madison Park. The pontoon is located on the west side of the existing 206-foot-wide channel, reducing the channel width to 120 feet. The narrower channel is marked by traditional red and green buoy channel markers. This new configuration (pdf 596 kb) will be in place until additional pontoons are joined with Pontoon A.

A new exclusion zone is also active immediately north and south of the 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.

Due to construction activities, the east navigation channel under the SR 520 bridge is currently obstructed. The channel will be cleared during specific weekends and holidays as listed below.

Note: When the channel is open, it is 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 follow the instruction below to request a drawspan opening.

SR 520 drawspan operations for boats over 45 feet tall

Hours Weekdays Weekends
Midnight - 6 a.m. Drawspan opens any time with minimum 2 hours advance notice Drawspan opens on the hour and half-hour with 2 hours advance notice
6:30-10 a.m.
(Morning peak commute)
No drawspan openings
10 a.m. - 2:30 p.m. Drawspan opens on the hour and half-hour with 2 hours advance notice
3-7 p.m. (Afternoon peak commute) No drawspan openings
7 p.m. - Midnight Drawspan opens any time with minimum 2 hours advance notice

Drawspan opening requests
To request an opening of the SR 520 drawspan for vessels over 45 feet tall, call 206-440-4490.

To keep the bridge in good working order, WSDOT may need to suspend drawspan openings if wind speeds exceed 30 miles per hour. Drawspan openings will resume as winds subside.

2015 special dates
When the drawspan is closed, as early as Feb. 14, 2015, both the east and west navigation channels will be opened. If this date is delayed, both east and west navigation channels around SR 520 will be open on the following dates in 2015.

  • Opening Day of Boating Season
  • Memorial Day weekend
  • Independence Day weekend
  • Seafair weekend
  • Labor Day weekend

Note to boaters: WSDOT, and the region’s commuters, appreciate your flexibility in working with us to operate the SR 520 drawspan. Help us keep boats and traffic sailing by providing as much lead time as you can and letting us know if you have flexibility in the timing of your request. The chart provides information on the minimum notice required of boaters in order to open the drawspan.

You can also print a quick reference guide (pdf 360 kb) with this key drawspan opening information.

What do drivers need to know?

WSDOT will work with boaters to minimize effects on the traveling public.

Before construction, bridge closures and drawspan openings were allowed only 9 p.m. to 5 a.m. weekdays and on weekends with two hours notice with the understanding that the west channel allowed 45-foot-tall boats and the east channel allowed boats ranging from 55 feet to 64 feet.

Also according to Coast Guard rules, both the west and east navigation channels will be open on several major events and holidays when boat traffic is heaviest.

Those dates include opening day of boating season, Memorial Day weekend, Independence Day, Seafair weekend and Labor Day weekend.

Sign up to receive text message or email updates about drawspan openings. Openings are also posted on VMS signs (pdf ) on highways leading to SR 520.