Saving the environment is the alarming red-hot topic of this trendy world. A proper arrangement is required to monitor different environmental pollutions. Many researchers and volunteers are developing and deploying Wireless Sensor Networks (WSN) for this purpose. Internet-of-Things (IoT) is one of the widely used cost-effective modern technologies to design wireless sensor nodes. Three fresh functional modules are introduced in this work to constitute the proposed work named as ‘Strengthening IoT-WSN Architecture for Environmental Monitoring’(SIAEM) which is indented to overcome some impuissance of applying generalized wireless sensor network architecture in the field of environmental pollution monitoring. The functional modules introduced in this work are Customized Clustering of IoT-WSN Nodes (CCIN) and Energy Aware State Change Routing Protocol (EASCRP). The objective of this proposed IoT-WSN architecture is to reduce the Latency, Jitter, End-to-End delay and Power Consumption whereas, improving the performance parameters such as Throughput and Packet Delivery Ratio. The impact of proposed method in the performance of IoT-WSN network is measured and stated using benchmark network simulator.