Design, construction, and preliminary hydraulic evaluation of a model rock ramp fishway

Abstract

Objective: New fish passage structures are frequently designed using information gained from existing structures, particularly those that have been shown to allow passage of the target species. However, this process rarely involves a preinstallation design and testing phase. Developing an apparatus that allows rapid and relatively low-cost testing of potential fish passage structure designs prior to field installations could reduce the reliance on a “build it, monitor it, does it work?” approach. Methods: To meet this need, we developed an indoor research flume at Colorado State University’s Foothills Fisheries Laboratory that housed a full-scale experimental rock ramp fishway. Result: The slope of the flume can be adjusted (0–10%) and integrates a set of four PIT tag antennas to allow fine-resolution tracking of fish movements in the fishway. The flume can deliver variable flows (up to 0.082 m3/s) of 9–25°C water. Lessons learned during the design, construction, and initial operation of the flume are presented here. Conclusion: The basic system could be adapted for similar studies in other regions and provides a robust and flexible infrastructure that could be modified for other evaluations of instream structures in lotic systems.