In summer 2018 WSDOT will replace a culvert that is a barrier to fish passage at Gribble Creek on State Route 9. The old round culvert will be replaced with a larger box culvert. Gribble Creek is located southeast of Mount Vernon in Skagit County. The creek passes through a culvert underneath SR 9 near between Big Rock and Big Lake.
Why is WSDOT
replacing the culvert underneath SR 9 at Gribble Creek?
As it’s currently configured, the culvert is a barrier to fish. Water flows are sometimes too strong for younger and older fish to swim through because the culvert is too narrow. Building a wider culvert will allow the creek to flow more naturally under the highway and improve the fish habitat in the area. This fish passage project is one of more than 800 culverts that are mandated to be replaced during the next 15 years. In 2013, the U.S. District Court for Western Washington ruled that the state must remove culverts that block fish passage under state roads.
What are the challenges of this project?
• Closing the highway: WSDOT is considering how to close the highway at Gribble Creek, between Cultus Court and West Big Lake Boulevard, to construct the new culvert. Staff is weighing whether to completely close the highway for about a week or to do a two-month, around-the-clock single lane closure.
• Keeping traffic moving: While WSDOT will offer the contractor incentives to complete work at Gribble Creek early, roughly 5,500 vehicles a day will be affected during construction.
• Working near wetlands: Contractor crews will need to be careful working near and above the creek to keep any construction material and excessive sediment out of the creek and wetlands.
The End Result
Building a new culvert at Gribble Creek will help restore the creek bed to a natural state and improve fish passage for salmon and steelhead, in compliance with the U.S. District Court ruling.
• This project will improve fish passage and open up additional salmon and steelhead habitat.
• The work will help WSDOT comply with the U.S. District Court ruling regarding fish passage.
What is the project timeline?
Fall 2017: Project will be advertised for competitive bidding.
Summer 2018: Estimate construction start date.
Fall 2018: Estimated construction completion date.
|Financial Data for PIN 100937H
||Amount ($ in thousands)
|2003 Gas Tax (Nickel Funding)
|2005 Gas Tax (TPA)
|Pre-Existing Funds (PEF)
How can I get more information?
15700 Dayton Avenue N.
Shoreline, WA 98133
WSDOT project engineer
1043 Goldenrod Rd.
Burlington, WA 98233
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