Preparadness: Activation of the stand-by system in pre-alert/alert with the remote sensors wireless communication of floating buoys that data captures the water elevation in real time and convey early warning signal to a local water station linked to the drone base sheltering a warehouse with 2 oz Pocket water Purifiers. 2-Activation and intervention Following the alert. take off drones flying over the flood plains drops water purifers like -a marshall plan- to the people at risk of drinking contaminated water 3-Assessment and lessons. Variation and uncertainty management along the PLC (Product life cycle) A drone could be replaced by the rider of a bike with a mobile phone or a speed boat. When the weather is fine any microlight could do it. Drones have been tested to flight in hurricanes (can be used in the weather forecast or in the flood relief to facilitate the delivery of drinking water at peaks of the aftermath when people can refrain to drink contaminated water -at least 72 hours-