US 101 Elwha River Bridge Replacement (WSDOT Lead)

Bridge replacement of the US 101 Elwha River Bridge, located approximately nine miles west of Port Angeles at MP 239.42. The existing three span, concrete arch structure has two in-water piers, was originally constructed in 1926 between two dams (Elwha Dam downriver and Glines Canyon Dam upriver), and hand not been subjected to a free flowing river until 2011 and 2012 when both dams were removed. It should also be noted here that the bridge is past the end of its original design service life. The current bridge was not built on nor secured into bedrock, instead it was built on river substrate.

Since dam removal and the resulting unregulated flow, the Elwha River has experienced increased velocities, river channel sediment loading and transport and associated channel migration. Because of the changes in river flow, the Elwha River bridge piers have experienced sever undermining. Initial emergency scour repair occurred in October of 2016. Due to unusually high flows and additional scour at the bridge piers since the initial scour repair, additional scour repair has been designed and permitted with construction to stat in spring of this year (2017) when river flow reaches acceptable volume/velocity ranging between 600 and 800 cfs. WSDOT continues to monitor the existing bridge and bridge piers for structural integrity and user safety until a bridge replacement alternative can be selected, permitted, and constructed.