Evaluation on sabo dam construction planning Matakabo River at East Seram island

Abstract

The Matakabo River is one of the major rivers in Maluku Province that crosses the Eastern Seram Regency. The Matakabo River is currently used for the Matakabo Irrigation Area through Matakabo Weir, with an area of + 3,050 Ha. Considering the number of tributaries entering the Matakabo River system and the risk of changes in land conversion in upstream, the development of Sabo Dam is seen as crucial for securing the water supply to irrigation as well as functioning as flood control. The location of 6 Sabo Dam is in Wai Sop, Wai Mol, Wai Sol, Wai Bemis, Wai Jana, and Wai Ines areas were based on visuals in the field where these areas are vulnerable to erosion and sedimentation. The calculation of flood discharge uses two methods, namely Nakayasu and ITB. Based on the highest river flow and flood capacity in the Q2: 401.68 m3 / second field which is close to the results of the synthetic discharge calculation from the ITB Method. Evaluation of 6 Sabo Dam with 1 Groundsill in Matakabo based on the calculation of the Van Rijn and Meyer Peter Muller (MPM) method will be able to accommodate sediment beds and suspended load around 1,275,958.63 m3 / year or around 0.581 mm / year. With 6 unit additional Sabo Dam locations (vol: 9,563,750 m3) equipped with groundsill, the estimated useful life of the river will not be disturbed by the sediment for about 7.5 years.