Concrete Sauk Valley Road MP 3.7
Public Works | Engineering Division
March 2026 Update
On March 25, 2026, Skagit County closed Concrete Sauk Valley Road at milepost 3.7 due to additional erosion sustained during a major flood event the previous week. The high waters further eroded the riverbank along the roadway, severely damaging the northbound lane, and it was determined to be no longer safe for traffic (see photos below).
Public Works was able to receive approval from the necessary permitting agencies to perform emergency repairs, which include placing angular boulders, rounded rock, and large woody debris to create a fish-friendly embankment before reconstructing the lost roadway. Skagit County anticipates providing an update on reopening the road by April 9, 2026.
Skagit County is continuing to apply for funding to support a permanent stabilization project in this area to prevent additional erosion and damage to the roadway from the Skagit River. The cost of this project is approximately $5M. We have received $500,000 from Representative Larsen’s office through a congressional appropriation in 2024 to support the design of the permanent repair.
Project Background
Concrete Sauk Valley Road was constructed within the historical Skagit River floodplain in the early 1900s. 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.
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 erosion of the county road after the river reached 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 staff 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.
