Stepped spillways are widely used in hydraulic engineering due to their ability to enhance energy dissipation and improve flow stability under high discharge conditions. This study examines how alternating steps in stepped spillways influence the flow characteristics. The study objectives were achieved by developing two numerical models with different step heights (3.6 and 7.2 cm) and configurations. Both models had a longitudinal slope (θ) of 26.6°. The models were subjected to flow rates ranging from 2.23 to 43.4 l/s to examine their flow characteristics. To simulate the turbulent flow, the Renormalized Group (RG) turbulence model is used in numerical modelling. The findings showed that hydraulic jump length increased from 15 cm at 10 m³/h to 145 cm at 150 m³/h, with numerical results slightly over-predicting by 5–10%. Conversely, energy dissipation decreased with increasing discharge, ranging from 90% at 10 m³/h to 54% at 150 m³/h. Also, the study finds that increasing step height results in greater energy dissipation and shorter hydraulic jumps, reducing stilling basin requirements. The results, with differences between simulations and experiments staying within ±3%, verify the model’s accuracy in capturing both jump behavior and energy dissipation in stepped spillways.
