Recent years have brought intense progress in the field of the three-dimensional modeling and visualisation of the urban planning concept. Virtual models of cities and computer systems for processing them are an indispensable tool of the contemporary urban planning workshop of today. The computers with the appropriate software create other chances for the development of new analytical methods, the using of which without applying computers is practically hampered or impossible. Geoinformatics research, techniques of laser scanning using the plane and processing aerial photographs, programme new solutions increased in the computing power of computers enable the automation and considerable precipitating of the process of generating models of 3 D cities. All innovative tools are a chance for the development and creating of spatial models of reality and should be one of the bases for the decision making concerning direction of the building development. The present article has an analytical character and shows another possibility is his purpose, which apart from amendments to planning documents and legal documents, could much help at designing the areas threatened by the danger of flooding.