Public Works Engineering
Thomas Weller, P.E.
Survey Current Road Construction Projects Skagit County Fish Passage Improvement Program Private and County Roads list |
Sauk Valley Road MP 3.7 Improvements
|
 Damage to CSVR after Spring 2026 Flood |
 Ongoing Emergency Repair Work April 2026 |
Background
Concrete Sauk Valley Road was constructed within the historical Skagit River floodplain in the 1960s. As with most infrastructure construction in this era, the focus of construction was to build as quickly as possible, which did not necessarily support the longevity of the road.
As seen in the photo from 1969, the Skagit River was well far away from Concrete Sauk Valley Road when it was constructed; however, rivers often find the path of least resistance and previous efforts to keep the river in its historical path were not substantial enough to prevent redirection of the main channel.
Aerial View of MP 3.7 in 1969
Aerial View of MP 3.7 in 2023
As seen in this photo from 2023, the Skagit River started an offshoot channel, which has only grown and migrated closer to Concrete Sauk Valley Road. Public Works has been aware of the channel migration since at least 2001, and the County has monitored the river’s progress towards Concrete Sauk Valley Road.
This area of the Skagit River is designated as “Wild and Scenic,” with the adjacent parcel owner being the U.S. Forest Service (USFS). When a Wild and Scenic River flows along or near a highway, USFS is legally bound by the Wild and Scenic Rivers Act, which prohibits federal agencies from assisting in any water resources project, including erosion control, that has a direct and adverse effect on the river.
The Skagit River is also populated by threatened and endangered salmonids species requiring Public Works to further consult with the Washington State Department of Fish and Wildlife for any project on the river.
With these limitations, Skagit County could only act to limit further erosion onto the county road after the river reached into the County’s right-of-way, and even then, our available armoring tools are limited.
Recent Work
Public Works has monitored this site for several years to evaluate the rate of bank erosion as flooding events occur on the river. Staff have planned and researched numerous options to control ongoing erosion at this site, but all options must also provide fish habitat features as required by the various permitting agencies. While options to both protect the roadway and protect endangered fish species are available, they are extremely costly.
In 2023, Skagit County Public Works crews shifted the driving lanes of Concrete Sauk Valley Road away from the riverbank to provide additional room for riverbank erosion and a possible construction staging area for future riverbank stabilization work. This will allow at least one lane of the roadway to remain open during construction for any future riverbank stabilization improvements. Construction would take place once permits have been acquired and riverbank conditions exist that require immediate stabilization of the roadway prism.
Drone footage of the new driving lanes below.
What’s Next?
In the long term, the Public Works department is evaluating and applying for funding for a permanent fix to the eroding riverbank. The project would entail installing bank protection measures with an emphasis on using natural materials when feasible, which could include concrete dolosse and large woody debris.
Stabilizing the riverbank is vital to ensuring Concrete Sauk Valley Road remains open and unimpeded to traffic. A closure in this area would require a 32-mile detour, delaying the reliable movement of freight and adding costs for businesses and motorists. A closure would also have a significant impact on the response time of emergency services. This portion of the Skagit River is designated as Wild & Scenic as well as prime habitat for several federally threatened salmon species. The County is committed to managing the road to not impact this fragile ecosystem.
Contact Public Works Engineering
Assistant County Engineer | Engineering Division Manager
Thomas Weller, P.E.
1800 Continental Place
Mount Vernon, WA 98273
Phone: (360) 416-1400
Fax: (360) 416-1405
email: pw@co.skagit.wa.us