Sedimentation in East Coast Hilly Terrain Reservoirs; Balimela, Odisha

Globally reservoirs behind dams are changing their hydrologic cycle under a shifting climate. Sediment, the flagship for water resources projects provide negative impact on environment and dam benefits. Sedimentation behind dams is continuous, regular through sequential paths that comprises of erosion, entrainment, transference from upper basin and deposition within the reservoirs. Present study envisages the morphometric study of the Balimela Reservoir active from 1972. The downloading of Geographic Information System (GIS), Remote sensing (RS) data from LANDSATS and making Stream order, Contour, slope and aspect maps by constructing Digital Elevation Model using the various Arc-GIS tools. The average bifurcation ratio is safe.. Considering the water-spread areas at various elevations of the years 2000, 2002, 2013, 2016, 2019 and 2022, the sediment deposits and reduction of storage volume by 29.945% by Jan 2022 since first impounding. The dam housed in hilly terrains, so there is less increase of catchment erosion except deforestation. The water from the dam optimally used by both the states Odisha and Andhra Pradesh. Preparation and strict adherence of concrete reservoir operation rule, upstream proper upstream maintenance and best catchment treatment plans shall increase the dam’s longevity and utilities.