Graduation Date
Summer 2017
Document Type
Dissertation/Thesis
Program
Master of Science degree with a major in Environmental Systems, option Environmental Resources Engineering
Committee Chair Name
Dr. Margaret Lang
Committee Chair Affiliation
HSU Faculty or Staff
Second Committee Member Name
Dr. Eileen Cashman
Second Committee Member Affiliation
HSU Faculty or Staff
Third Committee Member Name
Dr. Mark Henderson
Third Committee Member Affiliation
HSU Faculty or Staff
Keywords
Hydraulics, Ecohydraulics, Fishway, Pool-and-Chute, Anadromous Fish Passage, Fisheries Restoration, Coastal Watersheds
Subject Categories
Environmental Resources Engineering
Abstract
This thesis presents the hydraulic characteristics and simulated passage efficiency of a hybrid pool-and-chute, vortex weir fishway designed by Michael Love & Associates. A physical 1:15 scale model was constructed and evaluated at an 8% slope over three prototype flow rates representing high and medium fish passage flows. The highest velocities and turbulent kinetic energy (TKE) values were concentrated along the fishway centerline at the high and medium flow rate and the pool sides showed lower velocities and TKE. Large eddies spin laterally and longitudinally throughout each pool. The velocity vector directions at the lowest flow rate measured differed from the two higher flow rates with larger, more pronounced eddies on the pool sides.
The fishway’s velocities and their spatial distribution were used to estimate passage success and fatigue level. A preliminary numerical model was created that simulates a steelhead or coho salmon ascending the fishway. This model uses observed size distributions for adult steelhead and coho from data presented in the literature and calculates each individually sampled fish’s passage time and percent fatigue. Two swim pathways were analyzed at both the high and medium flow rates. A thousand fish of each species were simulated ascending the fishway, and zero fish reached 100% fatigue under any scenario. Results indicate that ascension of the prototype fishway should not be energetically limiting for steelhead or coho salmon.
This model was also used to calculate the maximum fishway length (holding the original 30-feet width constant) over which zero fish reached 100% fatigue, assuming fish did not rest and recover from fatigue within the pools between weirs. Results indicate the fishway length could increase by an additional three pools and weirs or 37.5 feet without causing any fish in the sample distribution to reach 100% fatigue. Conservative fishway design would not recommend increasing the fishway length beyond the length where fish reach 100 F% to ensure an energetic factor of safety and account for potential behavioral or motivation delays. Further investigation into the nature of fish use of the new prototype fishway design could help calibrate the models presented in this thesis and increase the accuracy of the passage efficiency estimations.
Citation Style
Harvard-Anglia
Recommended Citation
Foster, Brendan, "An investigation of the hydraulics in a prototype pool-and-chute, vortex weir fishway for anadromous fish passage." (2017). Cal Poly Humboldt theses and projects. 57.
https://digitalcommons.humboldt.edu/etd/57
Included in
Civil Engineering Commons, Environmental Engineering Commons, Hydraulic Engineering Commons, Other Civil and Environmental Engineering Commons