Floods are significant natural disasters that cannot be prevented, severely impacting urban infrastructure and agricultural land. This study evaluates the susceptibility of the Nethravathi basin, covering 3657 km2 in Karnataka's Western Ghats, to flood hazards. Serving as the primary drinking water source for Mangalore and Bantwal, the basin receives an average annual rainfall of around 4000 mm, with peaks reaching 4200 mm. This study uses the Analytical Hierarchy Process with a GISGeographic Information System (GIS) to identify key factors such as terrain, elevation, and river curvature that affect flood risk. Consequently, Mangalore City, Bantwal, and Uppinangadi are recognized as high flood-prone zones, characterized by flat terrain and significant construction activity. The confluence of the Nethravathi and Kumaradhara rivers at Belthangady, along with the meandering flow of the Nethravathi near the Thumbe dam, contributes to rapid water accumulation and potential flooding along its banks. Flood inundation mapping reveals that inundation can spread up to 2 km, with a minimum spread of 200–500 m. The present study analyzes flood risk factors in the basin using GISGeographic Information System (GIS) and AHPAnalytical Hierarchy Process (AHP) to enhance flood managementFlood management and planning.