Modelling hydrologic processes is important for understanding how the water cycle works in different environments. Cities which undergo constant changes are subject to flood hazards resulting from severe rainfall. This paper aims to simulate severe rainfall, visualize the results, incorporating both spatial and temporal dimensions, and to make future recommendations for further studies on flood visualization. Visualizing the results from a rainfall simulation using GIS provides urban planners and others the means to view the dynamics of the surface runoff. At the same time, it makes accessible advanced querying and analytical tools. A hydrological model for the study area in Gävle, Sweden was used to simulate a 100-year rainfall. Through FME, the data was reduced, time-stamped and combined to a shapefile. Both 2D software, ArcGIS, and 3D software, ArcScene, were used for creating an animated flood visualization. This study shows that although 2D tested better by a group of planners and water professionals, the 3D was still considered more intuitive. The heightened sense of realism from 3D outweighs its drawbacks, and further studies are required to test different methods of 3D visualization.