Artificial intelligence techniques can be used to solve problems using a heuristic approach. This paper deals with a model able to verify whether there is groundwater in a given place, the quantity available and its quality. The system has been implemented in the logic programming language Prolog and runs on a personal computer under MS-DOS. The knowledge base has been constructed using degrees of certainty and other factors. The model has been applied to a region in Southern Italy, where data are available. The first results are encouraging and further questions about groundwater quantity and quality are being examined.