This Case Study explores flood forecasting systems from the perspective of its position within the flood warning process. A method for classifying the different approaches taken in flood forecasting is introduced before the elements of a present-day flood forecasting system are discussed in detail. Finally, the state of the art in developing flood forecasting systems is addressed including how to deal with specific challenges posed.<br> The target group of this case study are decision makers in disaster risk management and/or water management. The case study should help to understand some hydrologic basics of the flood forecast and assist in the administration and implementation of an appropriate flood warning system in a specific environment, to find the best solution for a region.<br> Best solutions depend mainly on quality and availability of data, the areas and/or points of interest, catchment properties, cross border catchments, and financial capabilities with special consideration of flood forecast.