Page - 224 - in Book of Full Papers - Symposium Hydro Engineering

2.2. STAGES OF ANALYSIS In the design flood analysis and flood routing analysis there are some related things that affect that is: • The Sengguruh Dam located on the upstream of the Sutami Dam, resulting in a flood reduction by Sengguruh Reservoir. Beside that the outflow from Hydroelectric Power Plant of Sengguruh also affect the flood discharge into the Sutami Reservoir. • The connection tunnel between the Lahor Reservoir and Sutami Reservoir affected on flood routing analysis. On the analysis also considered the incoming or outgoing discharge through the tunnel simultaneously by water level difference in both reservoirs. The tunnel gate is located in the Sutami Reservoir, the operation of the tunnel door is rarely done so that the tunnel condition is always open. • The outflow from hydroelectric Power Plant of Sutami is also taken into flood routing analysis of Sutami - Lahor Dam because the outflow value can reduce the peak flood discharge that occurring. Fig. 2 Chatchment Area System Scheme Several stages for the completion of this study are hydrological data processing which is principally rainfall design analysis for design flood and flood routing which include; a. Daily maximum rainfall analysis, b. Design rainfall Gumbel type I method, c. Probability Maximum Precipitation (PMP) analysis, d. Frequency distribution match analysis (Chi square & Smirnov Kolmogorov), e. Synthetic unit hydrograph analysis (Nakayasu), f. Design Flood hydrograph analysis, g. Curve reservoir capacity analysis and widespread reservoir (storage 224