USE OF A RESERVOIR SYSTEM FOR FLOOD CONTROL IN THE RUHR RIVER BASIN IN GERMANY: POSITIVE EFFECTS and LIMITATIONS

To avoid flooding in the cities along the Rivers Ruhr and Lenne, an online flood-management-system using the retention capacity of the reservoirs in the Ruhr catchment basin is successfully operated. The system is based on a comprehensive hydrological information network, an adaptive flood forecasting model and an effective flood warning system. Nevertheless additional model calculations revealed, that the flood protection effect of the existing reservoir system is limited up to 50-year floods. For that reason flood action plans have been developed in order to assess the risk of flooding with return periods of 100 years and more. Within these flood action plans so-called focal points were identified, the flood damage potential was determined and flood mitigation measure were proposed.