Author(s): Vincent Autier; Scott Jungblom

Linked Author(s):

Keywords: Fish Passage; Validation and Verification; Case Study

Abstract: Technical fishways work by breaking down the overall hydraulic head into a series of small, manageable “steps” that dissipate energy and provide navigable conditions for fish to pass otherwise impassable barriers. Successful technical fish ladders are best developed using a combination of biological knowledge and experience, research, and engineering. These practices combine specific skills to produce a single structure with the ultimate measure of success being the degree of passability to migrating fish species. Once the design criteria are selected, the fishway hydraulics must be developed with adaptability. Adaptability is necessary to address the following: fluctuation between theoretical and actual design values, differences between the design documents and actual constructed facility, and measurements accuracy during post-installation evaluation. The objective is to ensure the facility meets design intent and performs as expected. This paper examines the importance of performing sensitivity analysis on fishway hydraulics during the design phase, ensuring that the technical fish ladder operates according to the design criteria specified to the swimming capability of the target fish species. It looks at the selection of the weir-and-orifice coefficients and uses a case study to demonstrate how fishway effectiveness can be met. The case study includes project background and biological results. Dimensional and elevation verification of critical hydraulic components and confirmation of the fishway hydraulics will be covered. The case study involves Box Canyon Dam, an aging hydropower facility on the Pend Oreille River in the United States of America which recently went through relicensing with the Federal Energy Regulatory Commission.

DOI: https://doi.org/10.3929/ethz-b-000675921

Year: 2024