Study River Dynamics: Backwater Effect in the Upstream of Kelo Dam in Mahanadi River, Chhattisgarh, India

The river's hydrodynamics can be directly influenced by the temporary flooding resulting from the dam's reservoir. This, even without backwater inundation, leads to changes in the river's structure that can further affect its initial hydrodynamics. Over recent years, the repetitive flooding of the Kelo River has caused significant damage to the upper section of the Kelo Dam. Located on the Kelo River in Chhattisgarh, the Kelo Dam primarily contributes to backwater flooding and hydraulic responses in this region, resulting in substantial losses in terms of property, infrastructure, and livelihoods. The primary objective of this investigation is to assess the impact of backwater on the river under both stable and flood conditions. The study focused on the Kelo River, employing a steady-flow analysis through a geo-referenced HEC-RAS model. The hydrodynamic reactions of the Kelo Dam can be determined by studying the changes in the water surface profile, velocity distribution, and water coverage area with and without the dam. The findings indicate that the influence of backwater upstream of the Kelo Dam extends up to 8 km. In this region, the velocity decreases from 3.5 to 0.7 m/s. The results demonstrate the potential submersion of the Chirpaini area during high flood events. This study will be valuable for future planning aimed at minimizing the impact of backwater in the surrounding area.