Evaluation Of Culvert Designs For Juvenile Salmonid Passage

Focus Area

Wildlife & Ecosystems


Natural Resources







Research Idea Scope

Problem Statement:
In transportation programs, there is a need to address situations that may affect salmon and their habitats under the Endangered Species Act (ESA). Culverts can block upstream passage of fish and other aquatic organisms. The great deal of research and engineering conducted to date has resulted in the enhancement of the passage of returning adult salmon. However, recent research has revealed substantial upstream movement by juvenile salmonids and the need to pass this life stage has made the problem even larger in scope. Tens of thousands of culverts exist in the State of Washington alone, and many are judged as blocking juvenile salmonids from thousands of miles of habitat. Determining appropriate hydraulic and fish passage designs for new and retrofitted culverts before installation has both substantial cost and environmental implications. The optimal conditions for culvert passage by juvenile salmonids are not well understood and are a key area upon which to focus research.
Proposed Research:
In partnership with Washington Department of Transportation (WSDOT), Washington Department of Fish and Wildlife (WDFW), Alaska Department of Transportation (AlaskaDOT), California Department of Transportation (CalTrans), and Oregon Department of Transportation (ODOT), the Pacific Northwest National Laboratory (PNNL) proposes a phased program to address the hydraulic and behavioral issues associated with juvenile salmonid fish passage through culvert systems. This program addresses the testing and assessment of culvert designs, along with associated measurements of hydraulic conditions and fish behavior, occurring in full-scale physical models of culvert systems deployed in an experimental test bed. Experiments in the testing apparatus will measure the hydraulic conditions (velocity, turbulence, and water depth) associated with various culvert designs under various slopes and flow regimes and then relate these measures to repeatable, quantitative measures of fish passage success. The long-term intent is to develop the test bed into a regional and national-level capability that can be used by other agencies that need to develop appropriate culvert designs to enhance the passage of juvenile fish or other endangered aquatic species.

TERI Administrator Note (June 2007): Related Research

CalTrans: Developing a Methodology for Forecasting and Mitigating the Impacts of Highway Construction, Operation and Maintenance on Salmonids (Research Underway)

The research will provide sound easy to use methodology and assist Caltrans personnel: (1) perform high quality environmental studies in a timely fashion; (2) develop and implement appropriate cost effective mitigation for highway construction, operation and maintenance; (3) negotiate with resource agencies on salmonid issues; (4) complete projects on time and within budget; and (5) fulfill the obligations of environmental law.

TERI Administrator Note (June 2007): Research Underway
FHWA Pooled Fund Study: Juvenile Salmon Passage through Culverts (Underway)

Washington State Department of Transportation (WSDOT), in cooperation with partner state and federal agencies, as well as private partners, is currently leading a unique pooled-funding program to study juvenile salmonid passage through road culverts and evaluate designs of retrofitted culverts to improve the success of upstream passage by juvenile salmonids. A majority of this research is being carried out at the Culvert Test Bed (CTB) facility at the Washington Department of Fish and Wildlife (WDFW) Skookumchuck Rearing Facility near Tenino, Washington. From 2003 to 2005, Battelle
Pacific Northwest Division (PNWD) conducted hydraulic measurements and fish behavioral
research in a series of studies leading to evaluation protocols to be applied in further testing at the CTB during and beyond 2005.

Suggested By

2002 Research Needs Conference Idea Dr. Walter H. Pearson Pacific Northwest National Laboratory Marine Sciences Laboratory

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