In the past decade, we have seen growing interest in SHM based on wireless sensor networks and the reason for this is the poor installation and expenses of maintenance. WSNs allow a deep deployment of measurement points on an existing structure, facilitating exact and fault-tolerant damage identification techniques without installing a fixed wired infrastructure. We provide a hierarchical decentralized SHM system that executes flexibility-based damage identification and localization. Flexibility-based methods exactly identify and localize damage on a wider range of structures than the previous System, by externally correlating data across various sensors. Our hierarchical system organizes nodes into clusters using a novel multilevel search approach that incrementally activates sensors in the damaged regions, allowing much of the network to remain asleep.