The 4onse project studies non-conventional monitoring systems fully based on open technologies (hardware, standard protocols, software and data) for the management of resources and natural hazards in developing countries. After the design of hydro-meteorological stations and software for the collection, management and distribution of data, the study involves the installation of 30 stations in the Deduroya Oya river basin in Sri Lanka. The system will be analysed to fully understand the real cost of ownership, data quality and applicability in real situations. If properly validated, these systems can provide an alternative solution, effective and sustainable for the protection of property and human lives.