Hydrological analysis is an important stage in the development of water resources. Determining hydrological quantities is actually not too difficult if the data for analysis purposes is available in sufficient quantity and quality. The method used for the analysis of the planned flood discharge depends on the amount of discharge data and rainfall data. Based on the analysis of discharge data and rain data. For planning the storage capacity of the river crossing the railway bridge, using the Nakayasu Synthetic Unit Hydrograph (HSS) Method, the river water level to the JEKA 2 structure is 13.38 m and the river water level to the tracks is 16.38 m so that the railroad tracks at Bridge 2 can be said to be safe against the river water level. Hydrological analysis is one part of a whole series in the planning of transportation structures such as roads, bridges and railway bridges including flood barrier embankments and so on.