Enhancing the Performance of Vertical Slot Fish Pass by Using Flexible Hydraulic Elements: A Pliot Project for Çataloluk Small Hydropower Plant in Turkey

This study focuses on vertical-slot fishways which are commonly built in rivers around the world. Vertical slot fish passes are designed for large fish which have economic value, such as salmon and trout. But, in rivers there are small-bodied and weak-swimming capacity fishes which are ecologically important. In this context, it is necessary to make a structural modification to vertical slot fish passes to allow the passage of such small-bodied and weak swimming capacity fish. In this context, it is proposed to place flexible hydraulic elements in the pools. Recent laboratory experimental works showed that by placing brush blocks in the vertical slot pool, the flow energy is effectively dissipated by the vibrations and bending of the bristles leading an about 30% and 40% reductions in the average resultant velocity and the turbulence kinetic energy. Moreover, back of the brush blocks create resting areas for fish. A pilot study has been carried out at the vertical slot fish passage of Çataloluk Small Hydropower Plant (SHP), which is located in Ceyhan River Basin in Tekir Creek in Turkey. Accordingly, 3D velocities and turbulence quantities were collected at several points in the pool with Acoustic Doppler Velocimeter (ADV) for various discharges at the Cataloluk fish passage. Also, the pool depth was measured continuously through the year by using ultrasonic distance sensor. The results demonstrated that flow velocities were not changed considerably but the turbulence quantities increased in the pool with the increase of Reynods number. The movements of the bristles are simulated by Cauchy number. The Euler approach was used to obtain the distributions of the flow and turbulence characteristics (turbulence kinetic energy, Reynolds shear stresses, resultant and power velocity); whereas the Lagrange approach was used to quantify the fish kinematics in the pool. The objective of this study to investigate the turbulence structure and fish migration patterns at a prototype scale in a vertical-slot fish pass simultaneously under real-time operational conditions. Since the response of fish to different flow patterns is not yet clear, all results will be evaluated according to fish-ecological criteria in order to derive reliable designs.