Überschwemmungsgebiet

Überschwemmungsgebiet is the German term for land that can be inundated during flood events, typically along rivers, streams or coastlines. It denotes areas where flooding is possible under defined conditions and is used in flood risk management and land-use planning. The designation is reflected in flood hazard maps and accompanying planning documents.

Legal and regulatory context: In Germany, flood risk management follows the EU Floods Directive and is implemented through national and state laws, including the Wasserhaushaltsgesetz (WHG). Überschwemmungsgebiete are identified in Hochwassergefahrenkarten (flood hazard maps) and Hochwasserrisikogebiete (flood risk areas). They indicate where inundation can occur under specified scenarios, often corresponding to a 100-year flood, and where planning restrictions or protective measures apply.

Mapping and scope: The extent of an Überschwemmungsgebiet depends on hydrological conditions, topography and the chosen recurrence interval. Maps provide information about the potential flood extent and depth, and they guide decisions on construction, land use and infrastructure within the affected zones.

Planning and implications: Within Überschwemmungsgebiete, building and land-use changes are subject to restrictions and flood protection requirements. This can include limits on development, requirements for elevated or flood-proof construction, and the preservation of natural floodplains or retention areas. The designation aims to reduce flood damage and support resilient land management and flood defenses.

Climate and updates: Flood hazard maps are periodically updated to reflect changing conditions, including climate-driven shifts in flood frequency and extent. Regions along major rivers such as the Rhine, Danube and Elbe, as well as coastal floodplains, commonly feature Überschwemmungsgebiete in planning and regulation.