Following international developments and the new WHO Drinking Water Guidelines (WHO 2004) a process-orientated concept for risk, monitoring and incident management has been developed and implemented in this study. The concept will be reviewed with special consideration for resource protection (first barrier of the multi-barrier system) and in turn, for the Water Safety Plan (WSP) which adequately considers—beyond the current framework of legal requirements—possible new hygienic-microbiologically relevant risks (especially emerging pathogens) for the drinking water supply. The development of a WSP within the framework of risk, monitoring and incident management includes the application of Geographical Information Systems (GIS). In the present study, GIS was used for visualization and spatial analysis in decisive steps in the WSP. The detailed process of GIS-supported implementation included the identification of local participants and their tasks and interactions as an essential part of risk management. A detailed ecological investigation of drinking water conditions in the catchment area was conducted in addition to hazard identification, risk assessment and the monitoring of control measures. The main task of our study was to find out in which steps of the WSP the implementation of GIS could be integrated as a useful, and perhaps even an essential tool.