Sedimentation Yield Analysis of Hatnur Dam using SWAT and GIS

Sheikh Afreen; R.V. Shetkar

Abstract

Sedimentation in reservoirs throughout the world are leading to loss of reservoir storage capacitythereby reduces the useful lifetime of dams. Storage reservoirs built across rivers or streams tend tolose their water storage capacity progressively with the passage of time due to sedimentation. After thedesigned sediment deposition capacity of the reservoir, further addition in sediment deposits affectsthe reservoir regulation operations. It’s therefore necessary to assess reservoir sediment depositioncapacity and plan for certain preventive measures so that the designed life period is not affected. In thisstudy sedimentation analysis is carried out for a dam having very high sediment deposition. The damis Hatnur Dam, located in Jalgaon District of Maharashtra State. Sediment yield is becoming a seriousproblem for this dam resulting in siltation of the reservoir which not only has reduced the capacity ofdam but is also affecting the aquatic life and safety of the dam. Presently most of the dams in India arefacing the siltation problem. An insight into sediment transport and deposition mechanisms plays acrucial role in managing the reservoir operations efficiently. GIS (Geographic Information System)based SWAT (Soil and Water Assessment Tool) are used in this study to calculate the sediment yield ofthe Hatnur Dam, Jalgaon, Maharashtra. In this study data for 32 years, starting from 1982 to 2013 isused. It is observed that sedimentation rate in Hatnur dam reservoir varies between 1.155 MCM peryear to 28.594 MCM per year, with an average rate of 9.423 MCM per year by using SWAT model,which agrees with the observed rate of 7.902 MCM per year.