Effect of change of channel width in the downstream of the check dam on controlling sedimentation in Mrica Reservoir

Abstract

The increasing sedimentation of Mrica reservoir shows that the sedimentation control has not been effective. The sedimentation control has been made include the disposal of sediments that settle in the reservoir by dredging or flushing. However, the results are not optimal. This is caused by the large volume of sediment entering the reservoir each year. The controlling volume of sediment that goes into the reservoir has also been carried out by conducting a watershed conservation program and building a check dam in the upstream Mrica reservoir. However, the existing check dam is still less effective in controlling sediments, especially suspended load sediments, that are transported in the river. Therefore this study was carried out by adopting the sediment trap concept to deposit sediments that escaped from the check dam. This study simulated changes in the width of the downstream channel of the check dam by three variations using HEC-RAS. There was a width of 20%, 40%, and 60% wider than the initial width. The results showed the effect of changing the channel width on volume sediment deposited. Based on the results of the study, the change in width to wider than the initial width could increase the volume of sediment deposits.

An efficient and economic desilitation strategy for reservoir sustainable development under the threat of extreme flooding threaten

“…However, the regret result is often presented that the dramatic inflow discharge always carries huge sediment. Most of the check dams are filled up with sediment by several severe typhoons due to climate change (Ulfiana et al 2020). Then, the sediment removing approach needs to be conducted, such as the mechanism trucking and soil dredging.…”

Analysis of the Sediment Dredging Activities of the PB Soedirman Banjarnegara Hydroelectric Reservoir Based on a Technical and Economic Points of View

“…The flow of the Serayu River before entering the Mrica Dam is fed by two other major rivers, namely the Merawu River and the Begaluh River [4,5]. In addition, the Mrica Dam functions as irrigation and a place for fish farming [6]. This dam is located in Bawang District, Banjarnegara Regency, exactly 8 km west of Banjarnegara City, Indonesia with an altitude of about 200 meters above sea level.…”

“…The practical operational life of the Mrica reservoir is predicted to reach 50 years since it was built. However, in only about 26 years since the inauguration, the symptoms of siltation have become more evident due to the high level of sedimentation-erosion in the Serayu River Basin, and it is estimated that the operational age is only 4-7 years away [5,6].…”