Suitability Conservation Types Analysis of Panglima Besar Soedirman Reservoir

Abstract

Mrica Reservoir located in Banjarnegara Regency is amultipurpose reservoir. Based on the report of PT Indonesia Power UnitPembangkitan (UP) Mrica in 2016, the sediment of Mrica Reservoir hasentered the critical phase as it reached 114.25 million m3 and the value ofland-cover index of Mrica reservoir was 80% of the total watershed areawith the average sedimentation rate reaching 4.09 million m3 per year. Itis estimated that the reservoir will be full of sediment by 2021. The maincause of the high rate of sedimentation in Mrica reservoir is the changes inland use and agricultural-plantation activities in the upper river areas andalong the river flow of Serayu River, Merawu River, and Lumajang River. This study aimed to determine the appropriate type of conservation forMrica Reservoir. The method used was the Analytical Hierarchy Process(AHP), in which the determination of conservation efforts was based onsecondary data and observation. According to the current condition ofMrica Reservoir, the planned conservation efforts include two types, namely non-structural conservation and structural conservation. If theconservation begins in 2019, the total sediment in 2021 will decrease to74% and it is predicted that the sediment will be exhausted by 2056.

Analysis of the Sediment Dredging Activities of the PB Soedirman Banjarnegara Hydroelectric Reservoir Based on a Technical and Economic Points of View

“…The Soedirman Dam, often referred to as the Mrica Dam, was built in 1988 for a Hydroelectric Power Plant by damming the Serayu River [1][2][3]. The flow of the Serayu River before entering the Mrica Dam is fed by two other major rivers, namely the Merawu River and the Begaluh River [4,5]. In addition, the Mrica Dam functions as irrigation and a place for fish farming [6].…”

“…The practical operational life of the Mrica reservoir is predicted to reach 50 years since it was built. However, in only about 26 years since the inauguration, the symptoms of siltation have become more evident due to the high level of sedimentation-erosion in the Serayu River Basin, and it is estimated that the operational age is only 4-7 years away [5,6].…”