Session A3- culvert Design for aquatic organism passage

The Federal Highway Administration recently published Hydraulic Engineering Circular (HEC) 26 “Culvert Design for Aquatic Organism Passage.” This new stream simulation design procedure yields hydraulic and sediment mobility conditions within an embedded culvert that are similar to those found upstream and downstream of the crossing over a wide range of flow rates. By simulating the depth, velocity, and sediment transport capabilities of the channel over the site-specific range of passage discharges, it is reasonable to infer that aquatic organisms, such as fish, that are capable of passing up and down the channel ·will also be able to pass through the culvert. Species-specific information on swimming capabilities or behaviors is not required. The presentation will provide background and an overview of the 13 -step design procedure, which is the core of the HEC 26 design manual. Detailed technical information supporting the methods used ·within the design procedure and several design examples are included in the appendices of the manual. The best practices described in the manual will be evaluated and updated, as necessary, as research and application experience advances. The presentation will review the basics of the design procedure by illustrating its application on one case study. Comparison of case study results using the HEC 26 procedure with those generated by other design methodologies will be discussed