Hybrid Investigation on the Hydraulic Performance of a New Trapezoidal Fishway

The current study presents a new type of vertical slot pass. The main difference of this trapezoidal fish pass compared to the standard design of a vertical slot pass remains in the separation of the pools into two zones: the migration corridor and the energy dissipation zone. The structure is first investigated in a physical model to optimize the training walls and slot geometry in order to avoid recirculation of the flow. Velocity and flow depth data from experimental flow measurements is later compared to the three-dimensional numerical model which provides a deeper insight into the flow field. The proposed design is found to avoid large vortexes within the migration corridor. Moreover, uniform flow conditions are also found in the energy dissipation zone, thus providing an alternative corridor for fish passage.