Flooding events are no longer rare, floods occur all over the world. Accordingly, it is vital for the society and different authorities to work with flood mapping. To meet the goal of Uppsala kommun to map the risks of floods in Uppsala län, a map of the different areas around Funboån which are inside the area of risk for flooding have been developed. In the work, cross sections and the water flow have been measured. Moreover, an echo-sounding have been carried out in Funboån to map the bottom topography. From the bottom map and laser scanned data covering the study area, a terrain model was created. The terrain model was used to draw cross sections in MIKE 11-GIS which represented the characteristics of the surroundings along Funboån in the hydraulic module MIKE 11. Furthermore, the 100-year flow has been calculated for Funboån with different methods and the calculated maximum flow has been estimated. These flows were used as input to the MIKE 11 model. The results of the MIKE 11 simulations show that large parts of the areas surrounding Funboån would be flooded as a consequence of extreme flows in Funboån. The areas flooded in the model of Funboån are well consistent with contour lines, heights of the terrain model and orthophotos. Some weaknesses did emerge in the flood mapping as a result of incorrect interpolation between some of the cross sections. The main uncertainties in the model of Funboån lie in the determination of the water flow and size of the Manning number, however, there sensitivity have been identified. The measures simulated to reduce the flooding with changing the values of Manning’s number and changing the appearance of some cross sections didn’t affect the extent of the floods except from some reductions around the area of the church of Funbo. The model for Funboån can be used to produce flood maps and simulate water levels. However, to secure the validity of the model the flow in Funboån should be determined more accurately. Also, with advantage, the calculated maximum flow should be developed for Funboån.