Reservoirs are designed with distinct storage zones: dead storage (below the lowest outlet level), live storage (available for regular supply), and flood storage. Over time, sediment-laden river flows drop their load upon entering the low-velocity reservoir pool. The proportion of sediment retained is defined by the Trap Efficiency $(\eta)$, which is primarily a function of the reservoir capacity to annual inflow ratio (C/I), typically evaluated using Brune’s Empirical Curves: $\eta = f(C / I)$ As sediment accumulates, dead storage fills first, followed by gradual reduction of live storage, ultimately determining the functional life of the reservoir. Monsoon-fed Indian rivers carry heavy silt loads, causing many large reservoirs across the country to lose storage capacity faster than original design estimates. To address this, the Central Water Commission (CWC) mandates periodic hydrographic and bathymetric surveys using modern dual-frequency acoustic echo sounders and Satellit...