The objective of this project is to establish a flexible and effective underground to above ground sensing and wireless network for real-time collecting water level and hazardous gases information from drainage and sewage systems. A series of sensor modules will be developed for the purpose of effectively monitoring water level change and gas concentration change within drainage and sewage manholes. Universal sensor interfaces including software and hardware interfaces, an efficient data compression algorithm, low power consumption technique for real-time sensing will be developed to ensure a long period of operation. To monitor the collected data at any time and at any place, the data management system will be built based on cloud computing and storage technologies. It provides real time data access and analysis for users. Meanwhile, APPs will be developed for on-site data browsing. With the sensing network, application software, cloud computing and cloud storage technologies, high risk area such as flood blackspots, manholes with high density explosive gases and even mountain landslide area will be closely monitored. Disasters can be predicted and eventually be prevented.