The water quality monitoring systems based on Water Quality Tele-Monitoring System (Water TMS) and Internet Protocol-Ubiquitous Sensor Network (IP-USN) are the representative IT based water management systems in Korea. Water TMS was introduced to improve the conventional method of assessing effluent charges for facilities discharging wastewater, and can perform real time monitoring and management of discharging facilities, enabling prevention of water pollution incidents. Water TMS also effectively establishes integrated watershed management systems by monitoring point-sources, and produces the raw data required to enforce Total Maximum Daily Load (TMDL) in the four major rivers. Water TMS can effectively establish a monitoring system in the four major rivers and is linked with automatic water quality monitoring networks. In addition, the monitoring system based on IP-USN that has been tested in the Four Major Rivers Restoration Project, can be useful in strengthening the water pollution monitoring system, and can contribute to the building of a base infrastructure for a future advanced intelligent society.