AHMAD RIFQI AOSRIB, YASSER ABD. DJAWAD AND GUFRAN DARMA DIRAWAN
Abstract
A decrease in the capacity of a reservoir due to sediment entering the reservoir exceeds the allowed rate. Therefore it is very necessary research that can provide information on the balance of sediment inflow into the reservoir and the sediment is allowed that can be used as a reference in maintaining the capacity of the reservoir sustainable capacity. Sedimentation rate control performed in Bili-Bili dam due to the avalanche of material Mount Bawakaraeng upstream reservoirs Jeneberang in order to function optimally. This study was conducted to obtain data on sedimentation rate, and the rate of sediment entering the reservoir capacity to know how long the sediment flow is not caused debris flow downstream reservoirs. The results showed that the changes in the surface of reservoir sedimentation results from 1997 through 2014 with a capacity of 75 million m3 volume into reservoirs distributed unevenly. The volume of sediment into the reservoir more concentrated predominantly in the upper area of the reservoir. Nevertheless dead storage area (capacity of the dead) near the dam still be controlled even if the sediment that reaches the area is only about 20%. Then, the volume of reservoir sedimentation is based on high-elevation surface shows that the majority (75.7%) sedimentation occurred at an elevation of 65 to 99.5 m in the amount of 56.835 million m3. Then at 15.069 million m3 (20.1%), which reached the dead bin reservoir at an elevation below 65 m. Dead storage capacity of the reservoir has been filled more than 50%.