A community based flood early warning system (CBFEWS) is an integrated system of tools and plans to detect and respond to flood emergencies that is managed by communities. The people-centric CBFEWS developed by the International Centre for Integrated Mountain Development (ICIMOD) emphasizes the four essential elements of early warning systems (EWS). Although the detection of a flood risk and its communication to vulnerable communities is driven by technology, the success of CBFEWS depends on a community’s preparedness to respond to floods.