Design of vertical slot fish ladder: review paper

Fish ladders are structures that are designed and constructed at water barriers, such as dams, to assist fish to migrate and complete their life cycle between different habitats without interruption or delay. The design of the fish ladders is considered a complicated process. It depends on two essential aspects; the biological and environmental nature of the fish. Consequently, hydraulic parameters such as velocity, turbulent kinetic energy, and flow patterns have to be designed to suit the fish’s capabilities without affecting it. This study is dedicated to performing an overview of the design of one of the most common fish ladders, the vertical slot fish ladder. A brief on an empirical and numerical design method is presented first. Then, a review of the recent literature on the vertical slot fish ladder design is explored. From reviewing several works on the design of the vertical slot fish ladder, it was found that important design parameters, such as the velocity of the flow, the turbulence, the slope of the fish ladder channel, have already been investigated in previous studies. However, it was observed that other important parameters, such as the slot angle, have not been investigated or explored in the literature. It is predicted that this parameter has a vital influence on the velocity of the flow inside the fish ladder which controls all other design parameters.