Integrated river basin management (IRBM) includes the water quality aspects but also flood plain and flood risk management as important elements of IRBM. On the other side land use and land use planning, respectively have a great importance on a sustainable river basin management. However, water management and land use planning are in generally separated in planning procedures and decision making processes. Even water quality and flood risk issues are often handled by different authorities. To identify interrelated issues, synergies and common goals information systems and simulation tools can be helpful. This type of software should provide functionalities to bring together different data and information with different geographic scopes, qualities, dimensions, et cetera. Moreover the interfacing of different models plays a central role. But not only simulation of natural systems is important. Stakeholder involvement and public participation are also essential. For decision making processes, technologies like Planning or Decision Support Systems (PSS/DSS) are important and can be very helpful. But for large-scale and complex catchment based systems, a series of frontiers as for example a good data base, administrative boundaries, data availability/access, standards of methodologies, communication (e.g., between water and environmental managers) exist. Development of DSS is usually time and money-consuming. So it is crucial to identify strategies and synergies to minimize costs and optimize benefits. Requirements for management tools such as interface standards, geo data infrastructure, flexible data management, cause-and-effect scenarios, and functionalities for communication have to be defined. Furthermore a planning instrument called "catchment development plan" with respect to geodata and DSS functionalities which integrates water management and land use planning aspects is presented in this paper.