In urban catchment areas the increasing urbanisation raises many problems for drainage. The successive growing of the development, the elimination of retention areas, the limited capacity of existing sewer systems and the elimination of receiving water change determine the runoff conditions. The sewerage inaccordance with growth has to be completed and extended. To get reliable values for design of sewers the observation of precipitation and flood events is required. By means of these data flood design events can be calculated using hydrological methods. That requires evaluation of the recordrd measuring data. in the urban catchment area of Annabach (0,74 km2), where the portion of garden amounts to 25 %, precipitation and water levels are measured and registered at some gauges. To design rating curves and to compute discharge hydrographs discharge measurements are carried outperiodically.