The Washington State Department of Transportation (WSDOT) is in the process of planning, designing, and constructing the State Route 167 Completion Project, which entails 6 miles of new highway and related infrastructure to connect the Port of Tacoma to the existing terminus of SR 167 in the city of Puyallup. The project site area is in flat, wet terrain, with several stream channels running through it. New highway construction will result in placement of earth fill in more than 15 acres of existing wetlands and over a mile of stream channel length. Existing streams and wetlands in the project area are severely degraded due to urban development and historical agricultural uses, yet Hylebos Creek and tributary streams and their floodplains are critically important for salmon recovery.
The SR 167 Completion Project represents a unique opportunity to alleviate chronic flooding problems, improve water quality, and restore streams and wetland throughout the project corridor, providing substantial ecological lift for fish and wildlife in the Hylebos Creek basin. These goals will be accomplished through what is called the Hylebos Riparian Restoration Program (RRP), an innovative watershed approach that involves a suite of aquatic and riparian improvements on approximately 150 acres of land adjacent to the new highway corridor. RRP implementation will result in a re-created stream channel network that includes wider, sinuous mainstem channels replicating historical stream characteristics, several miles of side channels and backwater channels, wider stream crossings, restored floodplain riparian and wetland areas with a variety of native planting zones, improved water quality, and wildlife features such as bat boxes, snags, turtle nesting mounds, and improved migration corridors.
The design of the Hylebos RRP has been a collaborative effort among biologists, engineers, landscape architects, geomorphologists, hydraulic modelers, and roadway designers. Implementation of the RRP has gained enthusiastic, widespread support from local, state, and federal agencies, the Puyallup Tribe of Indians, and other organizations interested in Hylebos Creek, and is seen as an integral component of the overall project. This presentation will highlight various aspects of the collaborative work done to develop the RRP design, innovative design features, and the path forward to construction using a design-build project delivery approach.