This paper proposes a novel Energy-Efficient Event- Driven (ESED) routing and data dissemination paradigm to address an open problem of wide interest in wireless sensor networks: the routing and data dissemination design for the applications with an event-driven data delivery model when geographic information is not available. ESED not only addresses the characteristics of such kind of applications, but also adapts to a dynamic network topology. First, to adapt to topology change with low routing overhead, ESED maintains direction vectors to data sinks through both global updates with a very low rate and timely local updates and detects multiple routes simultaneously. Moreover, data sources generate route detections upon detecting an event of interest and forward them to only a few directions. Finally, a node forwards route confirmations only to the nodes that have a need. Extensive simulation studies demonstrate that ESED achieves 100% success ratio of data delivery with low latency, low routing overhead, and low energy dissipation.