Submerge Barrier as a Sediment Trap In a Reservoir

Abstract

Sediment deposition and accumulation through the reservoir bed causes problems in the shortage and utilization of surface water as well as subsequent decline of reservoir economic and useful lifetime. The economic life time of a reservoir is defined as the time necessary for aproximately 100% of the initial dead storsge capacity to be filled with incoming sediment. While useful lifetime may be defined as the period in which a reservoir is still functioning even beyond the economic lifetime. Sediment barrier placed at reservoir bed affect the inflow pattern and, thus, intensify the increase of volume of sediment trapped before the sediment flow reach the reservoir dead storage. The purpose of this study is to investigate the effect of a submerge barrier on sediment deposition at the reservoir bed. The case study is Bakaru Reservoir located in Mamasa River, South Sulawesi, Indonesia. For this purpose, an experiment was carried out in Bakaru reservoir model with highly sedimented inflow “with” and “without” submerged sediment barrier. The model considers the factors affecting the reservor sedimentation and trap efficiency. The amount of sediment retained in the submerged barrier as the results of sedimentation was measured and compared with that retained without submerged barrier. The results obtained revealed that the submerged barrier improved the volume of sediment retained and thereby improve the reservoir trap effeciency. Since the sediment retained located outside and upstream of the dead storage, the sediment is easily dregged out without interfering the reservoir operation, thus, will increase the economic and theservice life of Dams.