Flood became an event that can be categorized as a disaster because it has the potential to cause losses. In the last two years, that is in 2022 and 2023, Meninting River has experienced twice flood disasters. In order to reduce the risk of greater disasters this research aims to analyze mitigation measures with an early warning system by using rain forecasts from the Meteorological Climatological and Geophysical Agency. From the hydrological analysis results, the rain categories that can cause flooding are heavy rain and very heavy rain. As for hydraulics analysis using HEC-RAS 6.0 generated areas around Meninting River that have the potential to be flooded, with the acquisition of correlation coefficient value (R) and error volume (VE) through the validation process model for SUH Nakayasu is 5.40%. The VE value for SUH SCS is 5.64%, while the R-value for SUH Nakayasu is 0.2, and the R-value for SUH SCS is 0.02. The VE value obtained shows that the simulated flood discharge volume has similarities with the measured discharge volume, in contrast to the correlation coefficient, which shows that the correlation between variables has a fairly low causal relationship. The utilization of rain forecasts from BMKG enables the identification of precipitation categories with the potential to cause flooding and some inundation in areas surrounding the river. Consequently, more intensive supervision can be conducted on river sections that have the potential to be affected by flooding.