HYDROSUCTION OF COHESIONLESS MATERIALS

Abstract

In ancient times, dams were built for the single purpose of water supply or irrigation. As civilizations developed, there was a greater need for water supply, irrigation, flood control, navigation, water quality, and sediment control. Therefore, dams are constructed for a specific purpose such as water supply, flood control, irrigation, navigation, and hydropower. India ranks third globally in major dams with about 6281 as per ICOLD (2023) Thus, reservoirs are formed by the construction of dams crossing natural drains such as rivers. The river will be going to lose its sediment transporting capacity, and sediment will deposit in the reservoir. Sedimentation generally results from natural and anthropogenic activities as studied by Obialor et al. (2019).Sediment accumulation is a serious problem in many parts of the world and has severe consequences for water management, flood control, water storage, production of energy, and reservoir benefits. Sedimentation can result in a decrease in reservoir capacity, obstruction of connecting structures, reduction in the clear depth of waterways, and damage to the rotor blades of hydropower turbines, and to the structure itself as studied by Jaiswal et al. (2024). Various methods employed globally to conserve the storage capacities of reservoirs are watershed management, conventional dredging, dry excavation, hydro-suction, sediment routing/sluicing, sediment bypassing, and sediment flushing through the reservoir, used independently or in combination. Hydro-suction is one of the techniques used to remove the sediment from the water bodies Ullah et al. (2005). This method uses energy from the hydraulic head available at the dam. Hydrosuction does not rely on external power pumps to transport sediment and therefore avoids various problems associated with those operations. Where sufficient head is available, operating costs for hydro-suction are substantially lower than for other types of dredging.