WSDOT Projects

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I-405 - Renton - Slide Repair and Culvert Replacement - Complete October 2008



Crews will replace a damaged culvert beneath I-405 in Renton. View project map.

Project photo View storm damage and repair photos
Project Facts
  • Temporary pump and pipe systems are diverting Thunder Hills Creek around I-405 until the new culvert is installed.
  • During heavy rains a temporary pipeline carries creek waters along the northbound shoulder of I-405, to Talbot Road, underneath I-405, and into a wetland.
  • The temporary pipeline is 2000 feet long.

Project Status

November 2008

  • Crews finished installing the culvert that will carry Thunder Hills Creek underneath I-405. See photos of the creek flowing through the new culvert.
  • Crews will spend the next few weeks removing the pumps and piping that have diverted Thunder Hills Creek during the repair work.
  • Get lane closure updates.

Last December crews installed two pump and pipe systems that divert Thunder Hills Creek away from the culvert that collapsed in the storm on Dec. 3, 2007. Crews are working to install a new culvert next to the site of the old one. 

Why is WSDOT installing a new culvert under I-405 in Renton?
On Dec. 3, heavy rainfall overwhelmed the culvert that carried Thunder Hills Creek beneath I-405 in Renton. The resulting rush of water created a sinkhole beneath the road surface, resulting in a collapse of a section of the culvert and threatening the stability of this section of the freeway. Crews have made temporary repairs to fix the sinkhole and have diverted water away from the culvert, and must replace the culvert to prevent significant damage to I-405 in the next storm.

Work on the culvert replacement is occurring in two stages. First, crews installed two pump and pipe system to divert Thunder Hills Creek away from the damaged culvert. One system pumps creek water into a nearby storm drain.  The other system activates during heavy rains and pumps water into a 2000 foot-long pipeline that carries water along the northbound shoulder of I-405, on Talbot Road (SR 515) underneath I-405 and into a wetland.  

In late March crews began work to install a new culvert underneath I-405. We expected to complete culvert installation by the end of July, but ran into problems with the tunnel boring machine.  Crews resumed tunneling and culvert installation in October and expect to have the creek running through the culvert by the end of October.

The End Result
The new culvert will have enough capacity to carry Thunder Hills Creek underneath I-405, and will reduce the risk of flooding and roadway failure in a major storm.

Project Benefits
Safety: The repairs will stabilize the road for drivers and will protect against future flood damage that could threaten the stability of I-405.

What is the project timeline?
Crews began repairs on Dec. 13, 2007. On Dec. 23 they completed the temporary pump and pipe system that diverts Thunder Hills Creek around I-405.  Prep work to replace the culvert began in March 2008.  The installation of the culvert started in mid June.  In July the project was delayed by problems with the tunnel boring machine and we halted work to develop a plan to recover the machine by tunnelling from the east side of I-405.  Tunnelling resumed in October.  The creek should be running through the new culvert by the end of October.

Public Involvement
Your thoughts and opinions are important to us. For more details about the project, contact WSDOT Project Engineer David Lindberg at lindbed@wsdot.wa.gov

Environmental Protection
As we design and build the repairs, we will take steps to minimize the effect on the environment. 
Please visit the WSDOT Environmental Services Web site for more information.

Increasing safety is one of our priorities
Repairing this stretch of highway will ensure that the road remains safe for drivers well into the future. Replacing the culvert beneath the road surface will  protect against future damage from floods.

Will this project impact tribal resources?
At WSDOT we seek to address the concerns of the tribal nations using the process outlined in Section 106 of The National Historic Preservation Act and the WSDOT Tribal Consultation Policy adopted in 2003 by the Transportation Commission as part of the WSDOT Centennial Accord Plan.

Financial Information
This project is funded through the following sources:

  • Federal emergency funds - $7.9 Million
  • 2005 Transportation Partnership Package  - $600,000
  • Total funding available from all sources - $8.5 million

How can I get more information?
Contact:
WSDOT Project Engineer Dave Lindberg
12277 134th Court N.E., Suite 200
Redmond, WA 98052
Phone: (425) 814-7104
E-mail: lindbed@wsdot.wa.gov

WSDOT Communications Meghan Soptich    
15700 Dayton Ave N
Shoreline, WA 98133
Phone: (206) 440-4704
E-mail: sopticm@wsdot.wa.gov

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