To find a more 'fish friendly' design for future stream crossings and for the thousands of retrofits expected to be completed in coming years, the Washington State Department of Transportation (WSDOT), representing West Coast transportation agencies, has hired Pacific Northwest National Laboratory (PNNL), to design and install a culvert test bed in southwestern Washington. PNNL, located in Richland, Wash., is operated by Battelle for the U.S. Department of Energy.
"We're blending the expertise of hydraulics engineers, mechanical engineers, statisticians, fish biologists and fish behavior specialists to find a solution to a problem that faces the entire Northwest, and has implications for culverts throughout the country," said Walter Pearson, PNNL fish behaviorist and program manager.
The full-scale, one-of-a-kind culvert test bed system is located at the Washington Department of Fish and Wildlife Skookumchuck Hatchery near Tenino, Wash.
The system allows scientists to adjust and measure the hydraulic conditions water velocity, turbulence and depth of various culvert designs being evaluated. By assessing different slopes and flow regimes, scientists can determine how these conditions influence fish behavior and the ability of the fish to pass through a variety of culvert designs being considered as retrofits.
"There are hundreds of possibilities for bed configurations," Pearson said. "A particular design may stop passing fish at some flow rate or some slope and that's what we'll be looking for. This will help us design stream crossings that accommoda
Contact: Geoffrey Harvey
DOE/Pacific Northwest National Laboratory