In 2004 the World Health Organization published the 3rd Edition of the Guidelines for Drinking-water Quality. It contains the description of a management system called Water Safety Plan (WSP), which includes a preventive and risk-based approach and follows the concept of Hazard Analysis and Critical Control Points (HACCP). The central elements of a WSP are a system analysis, hazard identification, risk assessment and the development of multi-level control points or one-time corrective actions. With these control measures in terms of the multi-barrier principle, a potential hazard to the drinking water quality should be timely detected and controlled with predefined actions. As a first barrier to protect drinking water resources, the catchment area is of particular importance. The scope of this thesis, which was executed from March 2007 to February 2010, was to analyse the WSP approach and find out its benefits compared to the present situation of groundwater protection for drinking water services. An executed case study shows the exemplarily development of a WSP for two wells in Wienerherberg, Lower Austria. The first step was a research of the current Austrian legal situation and the analysis of the existing requirements in the water act permit of the wells, in relation to preventive safety precautions. The hazard identification is based on a detailed description of the study area, as well as on a data collection and analysis of a duration rainfall and flood event in September 2007, including a series of measurements of the wells raw water quality regarding microbiological parameters. Particular attention was paid to the design of the catchment area, especially to the percolation through the vertical flow paths and the increase of duration of the infiltrating surface water in the unsaturated zone. Using the risk-based approach of the WSP, new control points are developed and an appropriate monitoring-programme is proposed.