The Prupuk River is a tributary of the Pemali River located in Bumijawa District,
Brebes Regency, Central Java Province. This study aims to determine the flood
discharge of the Prupuk River using the Nakayasu HSS model. The Nakayasu HSS
model requires data on rainfall and topographic maps. The methodology involves
conducting a Rainfall Frequency Analysis, Rainfall Intensity Analysis, Rainfall
Distribution Pattern Analysis, Effective Rainfall Analysis, and Nakayasu HSS
Analysis to estimate flood discharge. The results of the peak flood discharge
calculations using the Nakayasu HSS model are as follows: for a 2-year return
period, the discharge is 11.67 m/second; for a 5-year return period, it is 13.92
m/second; for a 10-year return period, it is 15,30 m/second; for a 25-year return
period, it is 16.96 m/second; for a 50-year return period, it is 18.14 m/second; and
for a 100-year return period, it is 19.28 m/second.