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The Washington Department of Fish and Wildlife Washington (WDFW) and Department of Transportation (WSDOT) have jointly focused on needs in fish passage research on culvert analysis and design for both adult and juvenile salmonids. As a result of recent workshops and information from other west coast states related to ongoing research, the following highest priority research projects were determined to be essential, urgent and critical transportation research. These agencies are currently undertaking these research tasks. Some of the work is either under way or completed. Research proposals are currently being developed for the remaining topics. For more information on them, contact Jim Schafer, Research Manager at WSDOT jschafer@wsdot.wa.gov or Michelle Cramer, Chief Environmental Engineer at WDFW Michelle.Cramer@dfw.wa.gov.
Stream Simulation in Culverts
A new approach to road culvert design for fish passage is being developed in Washington State where natural stream channels are constructed or allowed to develop inside a culvert. The design criteria for the culvert is focused more on channel stability as opposed to channel velocity. To date about 10 have of these projects been designed and constructed with variable success. WDFW currently has a design process for this at http://wdfw.wa.gov/hab/engineer/cm/.
An initial research project has been completed at Washington State University in Pullman Washington, where equations were developed for accessing bed stability (WEB site). This research is currently being tested and compared to existing sites.
The project developed design tools to build stable channels in culverts; a hydraulic flume was used to simulate a stream with different sediment types and sizes and has resulted in design parameters being developed for use in roadway culverts. Stable and unstable flow regimes were determined for various slopes, roughness and channel profiles.
Future research in this area needs to focus on the parameters which affect fish passage. Since the roughness is very high and the Q/A velocities low the main concern is turbulence. Turbulent stresses and intensities need to be measured for different channel configurations.
Juvenile Salmon Movement Timing
The scope of work for this project is currently under development, and will be a biological field evaluation of timing of major juvenile salmon movements associated with hydrology and other environmental parameters. The study will look at spring and fall movements for coho and chinook in Eastern and Western Washington. Existing upstream migrant trap data will be examined, and this study will try to coordinate locations with past work and ongoing studies. This project will be important in designing culvert options for streamcrossings, as critical passage timing can then be related to streamflow conditions.
A Study of Fish Passage Through Modified Culverts: Flume Study
This work will be primarily under controlled conditions in a constructed flume, where baffles, bed material, flows and culverts can be evaluated for fish passage. Information from past work relating to stable channels will also be biologically evaluated.
Initial work will be done in a flume to test a variety of bed and culvert conditions, flows, and slopes. Turbulence measurements will be made and related to passage success of different species and sizes of fish, with important information about fish capabilities to be developed which can be incorporated into effective designs.
We are in the process of developing the scope of work for this project at this time.
Modeling Hydrology for the Design of Fish Passage
While fish passage design flow prediction models exist for Western Washington, no models exist for Eastern Washington. Attempts in the past (Powers, USGS, etc) developed regression equations relating fish passage design flows to drainage area and precipitation. Evaluation of these models by WDFW has shown varied results, with a clear need for further development.
This research will gather flow data and develop reliable models for small streams throughout the state. Models would use watershed and climate characteristics; they would consider hydrologic provinces where appropriate, and high and low elevation and urban and rural watersheds.
Currently, WSU has developed a detailed proposal for this work.
Pool and Chute Fishways and New Channel Design
Detailed design standards will be developed for the design of new channels intended for fish passage and pool and chute fishways. Characteristics of channels will include hydrology, natural channel dimensions, slope, bedload, bed material, fish passage, and whether the bed is to be alluvial or fixed. Pool and chute fishways are an important style for retrofit for impassable culverts that are otherwise costly and difficult to repair. Capability of juvenile salmon to pass chute jumps will be addressed.
Pool and chute fishways are a recently developed hybrid fishway design mainly applicable to retrofitting existing culverts. New channel designs are used where culverts are removed and replaced with steep constructed channels.
The program currently has no proposals for this work.
Fish Passage Technical Assistance Index