Seite - 436 - in Book of Full Papers - Symposium Hydro Engineering

COMMISSION INTERNATIONALE DES GRANDS BARRAGES ------- VINGT-SIXIÈME CONGRÈS DES GRANDS BARRAGES Autriche, juillet 2018 ------- FINDING BALANCE BETWEEN WATER CONSERVATION, SEDIMENTATION, AND ENERGY IN DAM MANAGEMENT OF SERAYU- BOGOWONTO RIVER BASIN TERRITORY. CASE STUDY OF WADASLINTANG AND SEMPOR Vicky ARIYANTI Technical Planner, INDONESIAN COMMISSION ON LARGE DAMS PhD Candidate, ERASMUS UNIVERSITY ROTTERDAM Kisworo RAHAYU Hydrologist, INDONESIAN MINISTRY OF PUBLIC WORKS AND HOUSING, SERAYU OPAK RBO INDONESIA 1. INTRODUCTION Sedimentation has been the most challenging problem faced by any dams in the world. This condition is worsened by climate change effects. The climate change shifted the rainy season in Java Island to heavier rainfall in a shorter period of time, which forced the upstream farming area produce extra sedimentation to the dams downstream. The study uses case of two large dams in Serayu-Bogowonto River Basin Territory: Wadaslintang and Sempor. Both are located in mid-stream of the rivers and faced with the different scale of sedimentation problems. For both dams, the sedimentation is worsened due to the rapid changing upstream land use of the catchment (1,2) combined with the impact of climate change (3), which add the probability for landslide and flash floods falling into the reservoirs. However, the current dams operation managers’ work only on the focus of water availability data. They lack the tool to analyze whether the way they manage these dams has a balance point. This paper seeks to find and compare what is considered as ‘the balance of water conservation-sedimentation-energy’ for both locations using the Nexus approach for water governance (4). The locations are selected based on the existence of data for the bio-ecological 436