ABSTRACT
Nowadays, many dams in Indonesia have sedimentation problem. This condition would cause lots of damage if it happen continuously. There are many methods taken to reduce dam sedimentation, some of the frequent measures are dredging and flushing in the reservoir, which is very costly. Moreover, if it is not followed up with a comprehensive development in the upstream area then this methods will become less useful and ineffective. Another way to overcome this issues is by reducing the sedimentation from the upstream by built a checkdam (Renwick et al. 2005). However with some modification this checkdam become more effective by adding sediment pond which located off stream of the river to accommodate the maintenance activity. The research was done by conducting continuous monitoring on water level, field measurement, and sediment sampling. The objectives is to detain the sediment by the sediment control structure in the upstream river to reduce the sedimentation rate to downstream river. The study case take place at Cikamiri River which is one of the Cimanuk river tributaries in Indonesia. This river was measured as the highest sediment rate supplier to Cimanuk river which will flows to Jatigede dam. Based on the study results, the sedimentation on Cikamiri river reach 22,228 m3/year. Surprisingly, the sediment control structure can detain the sediment around 4,504 m3/year or 16% from the actual sedimentation on Cikamiri River. In a dry season the sediment flow about 1,180 m3 and in a wet season it reach 3,323 m3. This outcome shows us that the this sediment control structure is effective to detain the sediment in the upstream area before it flows to the reservoir.
