Hydraulic and Other Complexities of WSDOT Fish Passage and Stream Restoration Design Projects

Year: 2022
Presenter/s: John Monahan
Symposium Session: 2022 - 04 Stream Restoration from the (WSDOT) Transportation Perspective
Topics covered: fish passage, fish-salmon, hydraulics, instream structure (culvert/bridge/dam), modeling, and stream


In March 2013 the State of Washington was required, by Federal injunction, to correct hundreds of fish passage barriers in the Puget Sound by the year 2030. This presentation provides an overview of several advancements and challenges with hydraulic designs being completed for Washington State Department of Transportation (WSDOT) fish passage and stream restoration design projects, in response to the injunction. WSDOT’s Hydraulics Manual (HM) and the Water Crossing Design Guidelines (WCDG) produced by Washington Department of Fish and Wildlife (WDFW) serve as primary references for design teams, and continue to be updated and refined as restoration practices adapt to the widely varying natural and anthropogenic conditions, and project delivery methods. For example, practitioners are challenged to produce robust preliminary designs that may be used by WSDOT as reference documents in design-build bid packages, but preliminary designs do not have important final design refinements like scour, large woody material design placement, wood stability, or streambed material placement. Designs represent a static, as-built condition, but are typically intended to include deformable elements to foster natural channel processes resulting in hydraulic and habitat complexity and associated sediment and channel response for improved performance. Therefore, involvement of interdisciplinary fish passage and stream restoration design practitioners, from concept to completion of construction, is essential to successful completion of fish passage and stream restoration design projects. However, WSDOT staff, WFDW and Tribal partners are heavily loaded with projects and cannot support contractors at all sites. With an ever-growing urgency to complete projects to meet Federal injunction requirements by the year 2030, WSDOT continues to solicit external support and has developed fish passage and stream restoration design certification training. We recommend that fish passage and stream restoration design practitioners not already engaged in this project, but available to do so, look into the training and contract opportunities. There is much to do, and little time to do it in.