This Book, is produced in the framework of the project "Community networks for disaster reduction", which aims to set up an early warning system in 26 communities located on the riversides of Cañas-Lajas, Pirris-Parrita and Reventazon-Parismina. Its goal is to develop novating experiments based on community education and the implementation of early warning systems on those flood-prone riversides. (UNEsCO)