E.N. Cahya, V. Dermawan, M.N. Hidayat
A model test was conducted to determine the function and hydraulic characteristics of the spillway, as well as to establish the dimensions of the spillway section, side channel, transition channel, launcher channel, and stilling basin. As a result of the tests, the optimum features of the spillway are to be proposed from both hydraulic and structural perspectives. The physical hydraulic model test, scaled 1:60, was planned in accordance with the design results of the detailed design planning study that had been carried out. Observation of the model test results in the laboratory is carried out to determine the condition of the flow hydraulics behavior that occurs, especially in the phenomenon of reducing the energy of water flow in the energy dissipator and scouring on the downstream riverbed. This study aims to investigate the hydraulics of flow conditions at the labyrinth spillway system as a whole and to examine the scour conditions in the downstream river resulting from the flood discharge through the dam spillway. The results of data analysis from the hydraulic model test provide an overview of the flow behavior in the spillway system, which is improved in terms of energy reduction and scour, following modifications to the initial design. It was found that the hydraulic behavior exhibited more optimal performance in handling higher discharges of the spillway system. © 2026 Published under licence by IOP Publishing Ltd.
Water Resources Engineering Department, Faculty of Engineering, Universitas Brawijaya, Malang, Indonesia
