Old Highway 100 closed after 400‑foot slide; geotechnical analysis underway

Franklin County engineers told the Washington Area Highway Transportation Committee on June 30 that Old Highway 100 remains closed after a slope failure affecting roughly a 400‑foot section near the Old Seaco parking area.

Jim, reporting for the county, said geotechnical crews cored more than 90 feet in one location and more than 100 feet in another to evaluate subsurface materials. ‘‘They cored down over 100 feet in an area, over 90 feet in another area. And it's silt sand, and just debris,’’ Jim said. County staff said geoengineers currently are analyzing shear strength and settlement data and will deliver recommendations ‘‘any day’’.

Committee members requested rapid review and offered letter support for remediation if needed. Jim said the slide is close to the bridge but not the same failure that occurred up the hill; the slide area is ‘‘right in front of the parking lot at the Old Seaco’’ facility. The county will share the geotechnical report when it is complete and said stabilization options will follow the engineers’ recommendations.

No construction contract or funding source was announced during the meeting. The committee asked county staff to provide any assistance or formal letters the county requests as the study and repair plan proceed.