Natural calamities like floods are inherently unstoppable and cannot be delayed. However, their impact can be effectively mitigated through the implementation of suitable strategies. An essential aspect in this regard is flood mapping, which serves as a pivotal tool in identifying vulnerable regions susceptible to potential threats. This research focuses on investigating the Idukki district, situated in the Southern State of Kerala, India, which is renowned for experiencing recurrent geohazards during the monsoon season. Notably, the district is characterized by the presence of several dams. The present study focuses on assessing the potential failure of 11 significant dams using the HEC-RAS software developed by the US Army of Corps. Additionally, flood mapping for each dam will be conducted using remote sensing and GIS software. The research represents a pioneering effort to analyze the possibility of dam breakage and to create flood maps for 11 dams within the Idukki district. The SRTM DEM data was incorporated as input to simulate the dam breach in the HEC-RAS model, while the flood mapping and risk assessment processes utilized Sentine-2B imagery. The HEC-RAS dam breach analysis provides essential parameters, including velocity, water surface elevation (WSE), and depth. Among these, the water surface elevation (WSE) data is utilized for subsequent flood mapping and assessment processes, employing GIS software. The research indicates that, based on the flood mapping of downstream areas of all dams, forest areas exhibit higher vulnerability to flooding.