An on-line monitoring system using LoRa based wireless technology for manhole cover is proposed. The system includes sensor sensing nodes, LoRaWAN network and application. LoRaWAN based IoT has very low power consumption for long-distance transmission. We use the accelerometer sensor to monitor the position, displacement or damage of manhole covers used in sewage systems. If these covers are moved or damaged, then LoRa board alerts the authorities LoRa gateway. The gateway is connected to The Things Network (TTN), a cloud-based crowd-funded open source LoRaWAN platform. The data is uploaded to the cloud and stored, and it will alert to the maintenance department. On TTN, our application will be launched and integrated with different features such as SMS.