Flood natural disasters are almost certain to occur every rainy season. Rain with very high intensity occurred on July 9th, 2023 causing an increase in water discharge which made the river overflow and the Kawanua Bridge collapse. In the upstream area of the river, there is Kawa check dam which has experienced a huge amount of sedimentation due to the top of the crest check dam being covered by fallen trees. This study aims to determine the magnitude of the rate of erosion and sedimentation that occurs in the catchment area in the upper reaches of the river and find out where the source of sedimentation comes from, then the most appropriate solution can be decided, and a similar disaster does not occur. This research used a USLE method to calculate the erosion and sedimentation rate. The results showed that 37.88% of the catchment area was classified as a low level of erosion. Meanwhile, the moderate level of erosion represented 29.42%. Sedimentation Management Good Practice (SMGP) is a concept used to analyze erosion and sedimentation problems. The recommendations given by the SMGP concept have sustainable characteristics that minimize damage to the water environment. Additional recommendations are given by collaborating between government institutions related to catchment area and forest area management authority.