SR 20 - Fish Creek and Lorenzan Creek Fish Passages

Project news

  • This contract was awarded to Strider Construction Co., Inc. February 2021.
  • Construction began July 19, 2021.
  • Traffic shifts on to a temporary bypass with single lane alternating signal controlled traffic on August 13, 2021.

Needs & benefits

This project provides for the improvement of fish passage in two locations along SR 20 in the town of Concrete located in Skagit County - one at Fish Creek (MP 87.82) and one at Lorenzan Creek (MP 88.78) by replacing existing culverts with two buried fish passage structures.  The existing culvert at Fish Creek will be replaced with a new four-sided box structure that is 19 feet wide to provide fish passage underneath SR 20. The existing culvert at Lorenzan Creek will be replaced with a new three-sided, bottomless, fish passable crossing that is 16 feet wide by 46 feet long. The proposed replacements are designed to provide a long term solution to future scouring and erosion of the stream bed.

What travelers can expect

Construction will begin on Lorenzan Creek in July, followed by Fish Creek in September. This project will temporarily occupy the Cascade Trail to divert SR 20 traffic around the construction work zone for up to 21 days this summer. During construction, 2,100 linear feet of the trail will be closed to the public to protect their safety. WSDOT will provide a detour for bicycles and pedestrians during the closure that is 0.65 miles, along town streets and sidewalks that are already suitable for pedestrians and bicyclists. 

Travelers in this area of SR 20 should expect a single lane with alternating traffic with a flagger or temporary signal seven days a week, 24 hours per day, during construction.

Once construction is complete, the traffic diversion will be removed and the temporarily disturbed areas will be revegetated with native species. Additionally, the project proposes to leave pavement behind on top of the Cascade Trail for the benefit of future trail users to better accommodate bicyclists, pedestrians and other non-motorized equipment. 

Why are we removing fish passage barriers

State highways cross streams and rivers in thousands of places in Washington State, which can impede fish migration. WSDOT has worked for nearly three decades to improve fish passage and reconnect streams to help keep our waterways healthy. WSDOT fish barrier correction is a priority. 


  • February 2021: Bid awarded to contractor.
  • July 19, 2021: Construction begins at Lorenzan Creek.
  • September 2021: Construction begins as Fish Creek.
  • Fall 2021: Construction complete. 


Financial Data for PIN 102057F
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $1
CWA $5,583
Total $5,584


RB McKeon

Melissa Ambler
Project Engineer

SR 20 Fish Creek and Lorenzan Creek fish passage project sites.