Three-year WSDOT culvert, bridge project near Bellingham will come with closures and bypasses
Work begins this spring on a three-year series of projects to build new bridges and widen culverts that carry several salmon-bearing streams under Interstate 5 south of Bellingham.
Cost of the project is close to $160 million and will be completed in three phases starting in April 2025, according to a statement from the Washington State Department of Transportation to announce the project. It’s part of a statewide effort to create easier passage for migrating and spawning as part of a court order that recognizes tribal rights.
Delays and detours are likely once the project is finalized, WSDOT said in an emailed statement and at the project website.
“The project is in the design phase. The length of closures needed at each construction site is still being determined. Timelines are subject to change as more design and permitting work progresses,” the statement said.
Locations for culvert replacement are:
▪ I-5 at unnamed tributaries to Friday Creek (milepost 241)
▪ Lake Samish Road at unnamed tributaries to Friday Creek (Exit 240)
▪ I-5 at Lake Creek (milepost 245.8)
▪ I-5 at unnamed tributary to Lake Creek (milepost 246.2)
▪ I-5 at Chuckanut Creek (milepost 246.8)
▪ Old Samish Road at Chuckanut Creek
Construction of the Lake Creek crossing, south of the North Lake Samish exit, is scheduled to start in spring of 2025. Travelers on northbound and southbound I-5 can expect nightly lane closures as temporary bypasses are built. I-5 drivers will use the temporary bypasses through summer.
Work at the Friday Creek crossing is expected to start in the spring of 2025. I-5 traffic will be reduced to one lane in each direction at two separate times.
First, southbound I-5 will close for 15 days and both directions of traffic will use northbound I-5, with drivers using one lane in each direction. Then, northbound I-5 will close for 12 days and both directions of traffic will travel on southbound I-5.
“Travelers should expect extended back-ups during this time,” WSDOT said.
In either 2025 or 2026 crews will build a new crossing under Lake Samish Road west of exit 240 at Alger, and that will require a two-week closure.
Construction on the Chuckanut Creek crossing is planned for the spring of 2026. That will involve temporary bypasses for both directions of I-5 while new bridges are built. Old Samish Road will be closed while southbound I-5 traffic uses that road as a detour.
Old Samish Road will stay closed after the I-5 bridges are finished because a new bridge is planned over Chuckanut Creek.
Restoration of the salmon stream channel habitat under the bridges is planned for the summer of 2027, WSDOT said.
In 2027, work will start at the North Lake Samish exit 246. Nightly lane closures are planned in both directions to build temporary bypasses for use through the summer while a crossing is built for an unnamed tributary to Lake Creek. A new culvert will be built under the existing lanes of traffic, and the southbound I-5 on- and off-ramps will be reconfigured.
