Bili-Hydrograph discharge or flow is a very important part in overcoming problems related to hydrology. Because the flow hydrograph can describe a time distribution of surface runoff in a measurement area and determine the diversity of physical characteristics of the watershed. The presentation of the flood hydrograph can use the unit hydrograph reduction method from the measured flood hydrograph if data is available and use the empirical formula, namely Synthetic Unit Hydrograph (SUH), which is a hydrograph based on synthetic watershed parameters. This study tries to examine the effect of synthetic unit hydrograph parameters based on the characteristics of the watershed in the irrigated area of Kiru-kiru, Barru Regency. The research location is in Barru Regency, South Sulawesi Province, precisely in the Kiru-Kiru River Basin using daily rainfall data from Mareppang, Manuba, Mangkoso and Ralla Stations. Based on the results of the discussion carried out, the largest difference in flood discharge obtained based on the Nakayasu SUH and Modified SUH, which is 2.19, is in the 200-year return period, while the smallest difference is 0.01, which is in the 2-year return period. This shows that the Modified Synthetic Unit Hydrograph method is quite good in determining flood discharge.

Keywords : Hydrograph, Synthetic Unit, Synthetic Unit Hydrograph Nakayasu, Synthetic Unit Modified.