Protecting people from water
Flooding is a natural event that cannot be prevented. Climate change, the increase in settlement areas, the development of floodplains and the reduction in the water retention capacity of the soil due to intensive land use are increasing the frequency and intensity of flood events.
The European Union adopted a flood risk management directive in 2007. It serves to assess and manage flood risks. The aim of the directive is to assess the adverse effects of floods on human health, the environment, cultural heritage and economic activities and to take measures to minimise risks on this basis. The district governments in North Rhine-Westphalia are responsible for implementing the directive. The current flood risk management plan for the Rhine, which also covers the Ruhr catchment area, was published in December 2021. The current flood hazard and flood risk maps for the Ruhr catchment area were last updated in December 2019. The flood hazard maps (HWGK) show which areas are inundated during floods and which water depths and flow velocities are to be expected. The flood risk maps show where the risk is particularly high, e.g. for human health or economic assets.
The maps are available for three graduated frequency scenarios and are to be revised by the end of 2025:
- HQfrequent: Floods that occur on average every 10 to 20 years, i.e. relatively frequently.
- HQ100: Floods that occur on average every 100 years.
- HQextreme: Extreme floods that occur significantly less frequently than every 100 years on average.