Power efficiency is a key issue in wireless sensor networks due to limited power supply. Buffer management is also crucially important in the scenario where the incoming traffic is higher than the output link capacity of the network since a buffer overflow causes power waste and information loss if a packet is dropped. There are many available buffer management schemes for traditional wireless networks. However, due to limited memory and power supply of sensor nodes, the existing schemes cannot be directly applied in wireless sensor networks (WSNs). In this work, we propose a multilayer WSN with power efficient buffer management policy which simultaneously reduces the loss of relevant packets. Unlike the conventional WSNs which consider the whole network as single layer, we divide sensor network topology logically into three different layers, each layer associated with different information collected from sensing environment. We show that our proposed multi-layer WSN can reduce the relevant packet loss and power waste for retransmission of lost packets.