Seite - 548 - in Book of Full Papers - Symposium Hydro Engineering

Fig. 2 Typical Detail Design of Sukamahi Dam Advantages of this type of dam (Dry Dam) are not only the lack of sedimentation in the reservoir, the water quality of the river either upstream or downstream of the natural dam and the supply of the upstream part of the river. Besides, the maintenance of river ecosystem is not disturbed as migration of fish can still go downstream and going home based on previous habit including material condition in all river area. The main advantage in flood control with dry dam is effective for flood control in the urban area, because with small storage and small resettlement it can delay the peak of flood maximally. The dry dam has a low operating cost and easy to operate because there is no water elevation setting so it can work without door operation. With the above reasons, an engineering operation is performed, which at the beginning of the rainy season, the water level of the reservoir is set to a low elevation so that at the beginning of the flood, the flood discharge flows freely through the tunnel. Fig. 3 The Concept of Dry Dam 548