Water Flood and River information System are the disaster prevention systems that The Ministry of Land Infrastructure and Transport and the municipality maintain. It is a system that collects the data of the rainfall, the water level, the dam data, and the water quality, etc. to defend people's lives and the properties from high water by the flood or the typhoon etc, and offers information to the river authority The computer information device equipment that the function was consistent became ef ficient, reduction in costs, the labor saving, and the miniaturization each year and depends on social circumstances.
At same time, According to social demand, and that turned Water Flood and River information System construction and system value-added strategy for change. We plainly explain the evolution of the method for construction of "Water Flood and River information system" that is a typical system of JRC.