Fishways - Historical Assessment of Design Practices
denil, fish passage, fish response, fish ladder, fishway design, Hydropower, instream flow, mechanics, structures, swimming
Journal or Book Title
American Fisheries Society Symposium
Fishway design has evolved in a conservative fashion. Initial costs or practicality have limited the development of some innovative structures. Conservative design stems from (1) a lack of hard data on fish swimming and leaping capabilities, (2) a lack of integration of fluid mechanics with fish capabilities, and (3) designs based on fish responses rather than on stimuli. This paper summarizes the state of the art in fishway design and the development of several more efficient fishway designs. The efficiencies are derived from a combination of more expeditious fish passage, maximization of the instream flow operating range, and less costly construction. When competing or conflicting water uses are present, such as in the development of small hydropower, the minimization of water use in the fishway can become a fourth consideration.