The paper presents the stages of development of DTM for fragment of ONP (Ojcow National Park). Model was created in order to illustrate potential flood zones of river Pradnik. In subsequent stages of the development are shown: Basic concepts of subjects taken in the publication, characteristics of research object, methodology of DSM implementation, elements of flood zones and assessment of flooded plots devastation impact on their cadastral and landscape values. The advantage of the method is a low cost and short time of DTM creation based on aerial photographs. Created model has also a relatively high accuracy of elaboration. It is noteworthy that for the area being elaborated independent survey were performed using classical and modern technology methods. The work results will provide a base for further analysis in order to determine the flood zones for mountain rivers. Described problem will be the subject of subsequent papers by the authors.