What happened to the bridge? What are you doing to ensure it does not happen again?

Contractor tunneling construction activities resulted in a sinkhole on the roadway. The sewer main underneath the bridge is being relocated in preparation for the larger bridge replacement project the City of Kenmore will undertake in 2019. NUD engineers decided to install the new sewer line underneath the road via tunneling to allow the bridge to remain open during construction. The tunneling work has been completed. With the existing sinkhole filled in and the road repaved, for this particular project, there is no further danger of road failure from sinkholes.

When will the sidewalk along the southbound lanes be restored?

The contractor will restore the sidewalk along the southbound lanes by the end of February 2019.

Was anyone at fault? Who is paying for the unexpected repairs/over-time costs? Does NUD have project insurance for this to help cover?

Both Northshore Utility District and contractors maintain insurance policies to protect from unforeseen damages as a result of construction. Tunneling work can be complex and high risk. At this time, it has not been determined which provider will cover the additional costs resulting from the sinkhole and corresponding delays in construction.

Why couldn’t NUD keep one lane open to keep traffic moving?

Although the northbound lanes on the bridge seemed stable, it was determined that the high traffic volume created potentially hazardous conditions. This is why the lane was initially opened for emergency vehicle access only while the sinkhole was being repaired.

Why didn’t NUD place more detour signs to help route traffic?

To help route commuters over the long and widespread detour resulting from the bridge closure, NUD crews obtained every electronic message board available as far out as the City of Kent. Additionally, crews staged orange detour signs along the route in both directions. We acted as quickly as possible and used all available resources to alert commuters all along the detour route, but recognize we were not able to reach every neighborhood affected. We have plans in place to secure additional signage should a future incident arise requiring the bridge’s closure.

What about the trees along the bridge vulnerable to being uprooted from the sinkhole?

Crews removed three trees (already planned for removal) on the west side of the bridge whose root structures may have been compromised by the sinkhole. At this time, NUD and Kenmore engineers do not foresee any further potential for fallen trees over the bridge roadway.

What does this project have to do with the upcoming bridge replacement? How will the bridge replacement affect traffic closures?

NUD’s sewer line replacement work is part of the City of Kenmore’s upcoming bridge replacement project; the sewer line had to be relocated to enable the bridge work. The City of Kenmore expects bridge replacement construction to start in Spring 2019. They will be sharing more detailed information on construction and traffic impacts in coming months. Please check www.kenmorewa.gov/WestSammamishRiverBridge for current information.

Who should I contact if I have questions about the bridge replacement project?

NUD engineer Valerie Tokumoto is the lead contact on the sewer line replacement project. Please direct inquiries to engineering@nud.net. For questions about Kenmore’s bridge replacement project, please contact John Vicente, City Engineer, at (425) 398-8900.