The Centre for Security Studies (KEMEA) is a security policy think tank in the Hellenic Ministry of Public Order and Citizen Protection. Charged with guiding the disaster management authorities and improving the efficiency of flood disaster monitoring and management, they sought to use remote sensing techniques with Landsat and Sentinel-1 SAR images to map flood extent and assess flood damage. A WebGIS platform was developed in order to catalog, organize and disseminate the valuable information derived from the data processing techniques. Additionally, it provides the end user web application. KEMEA used ERDAS IMAGINE for data processing. ERDAS APOLLO Professional constituted the core software for the WebGIS platform.