Lower Big Quilcene Riverscape Restoration and Bridge Replacement Jefferson County, Washington

Critical infrastructure updates and subsequent restoration of the surrounding floodplain eliminate county road flooding and improve safety for non-motorized traffic along the lower reach of the Big Quilcene River. A new bridge along with levee removal/relocation are part of a design emphasizing a number of habitat enhancement features. Otak completed baseline environmental documentation to support permit submittals for construction, led the road and bridge design, and supported the riverscape restoration design through detailed geomorphic, sediment transport, and hydraulic analyses.

Updating Critical Infrastructure while Reconnecting a Floodplain

Restoration of the Lower Big Quilcene Riverscape focused on integrated floodplain protection and the replacement of an 80-foot-long bridge with a 1,040-foot-long, floodplain-spanning bridge. The design was completed in close collaboration with numerous associated stakeholders, including the Hood Canal Enhancement Group and the Jamestown S’Klallam Tribe. From cultural elements, colored concrete selections, and an added emphasis on fish preservation, a number of functionally effective and visually compelling elements were a direct result of the tribal consultation process. The combined aesthetic choices for the Linger Longer Road Bridge replacement create an attractive structure that also harmonizes with the surrounding natural environment. For a channel that had been historically leveed, the new structure and restored riverscape allows more area for the floodplain to occupy, decreases sediment impacts to Quilcene Bay shellfish beds, and re-establishes a highly-productive corridor for salmon habitat. The features also improve recreational access to fishing, exploring, and wildlife observation.