DISTRIBUTION OF SEDIMENTATION IN CIRATA DAM AND TREATMENT IN EFFORTS TO MAINTAIN RESERVOIR’S AGE OF USE

• Main Author: Abi, Fakhri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/52124
• Institution: Institut Teknologi Bandung

Reservoir sedimentation is a problem that requires special handling in order to maintain the reservoir’s lifetime. Cirata Reservoir in particular is one of the largest power plant reservoirs in Indonesia. The last monitoring in 2017 by PT Pembangkitan Jawa Bali Badan Pengelola Waduk Cirata (BPWC), results that there was an average of 8,4 million m3/year. This study aims to perform a numerical analysis of the sedimentation distribution pattern based on the geometry, sediment and discharge data of the Cirata Reservoir. Numerical analysis was performed using SSIIM-2 (Sediment Simulation in Intakes with Multiblock Option) software. From the simulation results of flow and sedimentation using the dominant monthly average discharge for 5 years from 2013 to 2017, an average addition of sediment volume was 248,991 m3/month. When inspected from each river that becomes the inflow of Cirata Reservoir, the distribution of the contribution of sedimentation in the Cikundul, Cibalagung, Cisokan and Citarum rivers is respectively 12,19%, 20,34%, 28,39% and 39,07%. This value is obtained from the simulation results of sedimentation in each river for 5 years with the dominant monthly discharge. This means that the dominant sedimentation is obtained from the contribution of the Citarum River which is the outflow of the Saguling Reservoir. From the analysis of the sedimentation distribution to the position of the dead storage in the reservoir at an elevation of +180, it was found that of the total sediment that entered Cirata Reservoir, only 4,10% reached the elevation of the dead storage in the downstream area of the reservoir. These results can later be used to determine the appropriate sedimentation handling pattern and can be used for further analysis of the reservoir sedimentation rate against the dead storage capacity in future studies.