Howard Hanson Dam at Green River

WSDOT is working to keep drivers and the economy moving in the event of Green River Valley flooding.

The U.S. Army Corps of Engineers recently reduced the risk threat of flooding along the Green River to 1 in 60. The grout curtain in place appears to be effective. WSDOT continues to work with local and state partners to prepare for the worst-case scenario.

Water released from the dam could flood the valley, including state highways in Tukwila, Renton, Kent and Auburn.

• WSDOT is working with federal, state and local agencies on coordinated information and evacuation plans.
• During any emergency, we make plans to maintain and operate the highway system.
• Once floodwaters recede, we remove debris and repair roadway damage.

Getting prepared before a flood

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If you live, work or travel in the Green River Valley, learn flooding evacuation routes.  

Depending on changing conditions, some routes and ramps might close. Be prepared to take one of several routes. The latest information will be shared online and through the media.

• Before floodwaters rise, get prepared so you can safely leave the Green River Valley.
• During and after a flood, use the WSDOT website and regional links (at left) to learn which roads are closed.

Other ways to prepare:

• Be informed. Flood-readiness tips are available online through the King County Office of Emergency Management and the Washington EMD.
• Sign up in advance for e-mail updates from King County (RPIN) and WSDOT.
• If you have Twitter, follow Howard Hanson Dam and WSDOT for the latest news.
• Follow the WSDOT Blog.

Getting around during a flood

• If floodwaters rise, WSDOT will help and manage highway traffic in the Green River Valley.
• We will share state highway information with drivers.
• The flood waters could affect many state highways.

Please check back here for updates throughout flood season.

• View  larger map

  We will use all our traveler information tools and social media tools to provide information and keep traffic and the economy moving.
• We will post maps to show drivers what highways and ramps are closed.

Working together during a flood

We will work with multiple agencies on evacuation routes and make the best use of traffic management tools before, during and after a flood.

• We are coordinating with freight and transit groups to route buses and trucks.
• We inspect and monitor our highways, ramps and bridges and stockpile supplies.
• We have plans if floodwaters reach the WSDOT Kent Maintenance facility, located off SR 167.

Cleaning up after a flood

Once floodwaters recede, we quickly address:

• Debris on our roads.
• Needed repairs.
• Traffic management needed to keep drivers moving while work takes place.