Page - 225 - in Book of Full Papers - Symposium Hydro Engineering

area curve), h. Spillway capacity analysis, flood routing analysis (spillway) and river routing analysis, i. CWL determination as a safe guideline to get flood peak reduction in order to avoid the possibility of overtopping, j. recommendations on maximum water level control at each month as a guideline for reservoir operations related to avoid the possibility occurs overtopping. 3. RESULT AND ANALYSIS 3.3. DESIGN RAINFALL Based on the value of the maximum daily rainfall monthly and yearly at each point of review calculated the value of PMP rain and the design rain on the re-time of 1000 years with the gumbel type I method as a comparison. The following is the result of PMP calculations and the annual and monthly of design rainfall are presented in Table 1. The calculation of the synthetic unit hydrograph of Nakayasu method is done with the control point of Sengguruh Dam, Remaining Basin Sutami, and Lahor Dam. The result of the unit hydrograph analysis presented in “Fig 3”. Table 1 Page margins are as follows Description Design Rainfall 1000 years return period (mm/day) Probability Maximum Precipitation, PMP (mm/day) Sengguruh Dam R.B Sutami Lahor Dam Sengguruh Dam R.B Sutami Lahor Dam Annual 206.58 269.43 305.66 392.72 607.11 710.35 January 108.07 164.29 198.58 192.59 388.67 413.61 February 117.7 113.5 143.32 266.53 283.99 334 March 199.57 228.1 265.57 394.11 489.56 526.17 April 128.57 195.96 208.3 302.87 464.15 447.76 May 88.92 93.07 120.06 267.67 261.75 351.29 June 116.7 95.02 87.28 383.94 228.42 284.35 July 70.09 65.76 79.38 199.44 210.4 260.63 August 75.59 85.36 95.74 221.97 238.19 302.59 September 101.59 109.31 125.19 297.86 322.17 393.69 October 102.37 144.49 181.08 314.03 403.38 494.72 November 178.14 275.72 322.66 358.62 641.31 786.56 December 227.13 229.81 250.35 507.66 546.05 619.61 225