Krueng Kala River is one of the rivers located in Lhoong District with a length of 8,258 km and a watershed area of 15,701 km2. Lhoong District is one of the areas when entering the rainy season will be affected by floods. This is due to the overflow of water in the Krueng Kala River into residential areas and rice fields. The resulting impact is damage to houses and submerged rice fields. The purpose of this study was to estimate the value of the flood discharge on the Krueng Kala River using the Nakayasu and the Soil Conservation Service (SCS) Synthetic Unit Hydrograph Method. The calculation of flood discharge values with return periods of 2, 5, 10, 25, 50, and 100 years on the Krueng Kala River uses the Nakayasu and SCS synthetic unit hydrograph method based on maximum daily rainfall data for 10 years from 2 stations, namely Krueng Aceh Station and Siron Station. The results obtained from this study are the design flood discharge values for the HSS Nakayasu Q2yr, Q5yr, Q10yr, Q25yr, Q50yr, dan Q100yr methods respectively of 142,324 m3/s, 158,800 m3/s, 168,625 m3/s, 180,135 m3/s, 188,174 m3/s, and 195,818 m3/s, for the HSS SCS method are 120,616 m3/s, 132,594 m3/s, 139,736 m3/s, 148,103 m3/s, 153,947 m3/s, and 159,503 m3/s. There are several differences between the two methods, there are the form of graphs, peak times, and peak flood discharges. The graphic form of HSS Nakayasu is a condition of fast rising and slow falling, while HSS SCS rising and falling conditions are relatively almost the same. The peak time for HSS Nakayasu is 1,473 hours, while for HSS SCS is 4 hours. The last difference is in the peak flood discharge for HSS Nakayasu which is 1,231 m3/s.and HSS SCS is 0,722 m3/s. Based on the value of the discharge through the spillway, HSS Nakayasu is more suitable for use on the Krueng Kala River.