Sedimentation Yield Analysis of Hatnur Dam using SWAT and GIS

Abstract

Sedimentation in reservoirs throughout the world are leading to loss of reservoir storage capacity
thereby reduces the useful lifetime of dams. Storage reservoirs built across rivers or streams tend to
lose their water storage capacity progressively with the passage of time due to sedimentation. After the
designed sediment deposition capacity of the reservoir, further addition in sediment deposits affects
the reservoir regulation operations. It’s therefore necessary to assess reservoir sediment deposition
capacity and plan for certain preventive measures so that the designed life period is not affected. In this
study sedimentation analysis is carried out for a dam having very high sediment deposition. The dam
is Hatnur Dam, located in Jalgaon District of Maharashtra State. Sediment yield is becoming a serious
problem for this dam resulting in siltation of the reservoir which not only has reduced the capacity of
dam but is also affecting the aquatic life and safety of the dam. Presently most of the dams in India are
facing the siltation problem. An insight into sediment transport and deposition mechanisms plays a
crucial 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 of
the Hatnur Dam, Jalgaon, Maharashtra. In this study data for 32 years, starting from 1982 to 2013 is
used. It is observed that sedimentation rate in Hatnur dam reservoir varies between 1.155 MCM per
year 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.