Sustainable reservoir management by bypass channel (Soedirman reservoir case study).

The change of land use in the watershed area Reservoir Mrica, will cause erosion. The erosion has an impact on the amount of sedimentation carried by the river. Sedimentation of reservoirs will result in decrease in reservoir storage capacity and functional age of reservoir that will affect the performance and operation of reservoir. In this study focused on preventive efforts to reduce sediment transport at the mouth of the river before entering and settling in reservoirs, by switching sediment transport to bypass channel. The numerical model of HEC-RAS version 5.0.3 is used to simulate sediment transport. The application of the model by diverting sediment loaded flows through the bypass channel to the river downstream of the reservoir. In the condition of existing sediments entering the reservoir amounting to 13,254,770.00 tons / year. Furthermore, based on the results of the HEC-RAS simulation, it can be seen that the sediment bypass channel that enters the reservoir is reduced to 12,365,117.05 tons / year (which can reduce the sediment entering the reservoir by 6.71%) and the bypass channel by 731,543.58 tons / year Then with the combination of bypass channel and groundsill, the sediment entering the reservoir is reduced to 11,778,952.21 tons / year (which can reduce sediment entering the reservoir by 11.13%) and the bypass channel increases by 1,183,676.87 tons / year. So the model results are obtained with a combination of the bypass channel and groundsill providing the most optimal results in reducing the sediment entering the reservoir. [ABSTRACT FROM AUTHOR]