An integrated groundwater information system, which is a web-based platform, was developed to utilize and manage groundwater efficiently in Korea. The system was designed to input and modify data interactively by various users such as managers, well developers, and scientists. Groundwater database is coupled with a web-based modeling tool based on Analytic Element Method(AEM)(Visual AEM by James R. Craig in University of Waterloo) to assess groundwater resource and impacts from various factors such as climate change, hydrologic environment changes, and contaminant loading. The groundwater database contain the well locations and the related facilities, hydrogeological units and characteristics, geothermal data, water quality, various geo-spatial data including land use, soil type, geology etc. The groundwater modeling can be possible on the platform straightforward due to the information access in the same time. There’s a limit to what you can implement using the adopted AEM model, but it is powerful in that it can well reflect the characteristics of a large scale area flow system. The integrated system is called as GEE system, and it means Groundwater-(Geothermal) Energy-Ecosystem, which is the three components that make up the Groundwater Dependent Ecosystem(GDE). Through the development of the system, we intend to secure sustainable groundwater-geothermal resources and to maintain GDE according to climate change. Database were constructed for each of the three factors (groundwater, geothermal, ecosystem) as the components of the GEE system in the Geum river basin which is one of 4 largest basins. Furthermore, the database and groundwater modeling module on the platform in the Geum-river basin was tested and has been confirmed to be effective for a good groundwater management tool.