The most desired disaster prevention in Taiwan has to be typhoon; therefore there is a saying good weather, good life. The government does everything to prevent nature disaster, preparedness, response and recovery, especially on typhoon flooding survey. In order to conduct instant contingency handling disaster reaction in biggest disaster conditions, the government hopes to control the disaster immediately, and calculate the disaster loss. The main purpose of this study is to build a flood automation system. Apply auto-recording water level monitoring system (internal or external water) from water stations to collect stage data, and integrate Geographic Information System by the terrain grid computing, then obtain the instant scope of inundation and flood depth. Together with the instant rainfall and forecast to achieve the effectiveness of the flood watch or warning, then we should possibly control the instant information for the anticipation of the flood disaster. Taking it further with the Flood Security Plan, we have the best reference for decision-making use in the Emergency Response Center. The study area is located in Yilan County, the most sensitive flooded region, to set up immediate foregoing typhoon instant information system or so-called flood automation system, and then by several times of investigations and post-disaster flood scar volume measured we completely record ground hydrological information, and calibrate it with water level gauges built by Taiwan National Typhoon and Flood Research Center and AWRSIP weather telemetry information platform of synthetic aperture radar images on the flooded scope and depth. The concept of flood automation system is based on the fact that the occurrence and distribution of flood is not merely a product of chance, but the result of a combination of climatic, hydrologic, geologic, topographic and soil-forming factors that together form an integrated dynamic system, thus, through a combination of real-time rainfall forecast, flood recording, automation requirement, Geographic Information System, flood warning, instant data transmission and the internet, be setting up an ideal typhoon instant information system, which can become high accurate and be suitable for easy use of flooded areas, in order to achieve sustainable development in those areas.