New dimensions of reservoir sedimentation: a case study of Khodiyar Reservoir, India: Fid-Bau Portal

New dimensions of reservoir sedimentation: a case study of Khodiyar Reservoir, India

Majumdar, Pradeep Kumar

Medium and small reservoirs in water‐scarce regions face two extreme hydrological conditions. In years of lesser rainfall, inadequate water storage in the reservoir is a matter of concern. In contrast, flash floods portend disaster in years of better rainfall. There are also other possible hydrological, hydraulic and structural imbalances that may arise because of sedimentation. This study describes these dimensions, citing the example of Khodiyar Reservoir in Gujarat, India. The reservoir capacity was reduced by 36.12%, and a new zero elevation raised by 50% over 41 years. This study indicated the reservoir experienced silting at a much faster rate during the initial inflow years, reaching a regime state after 20 years. During this period, the water evaporation and seepage losses increased because of storage losses. In addition to reducing the flood return periods, sedimentation also could pose structural instability. The analyses of this study indicated the need for evaluating the regime condition in the planning stage to marginalize the effects of reservoir sedimentation on the socio‐economic aspects of water resources development.