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Flood protection

We understand flood as the state in a surface water body in which the water level or the flow have reached or exceeded a certain value (threshold value). Depending on the water level and the degree of adaptation of the use to (potential) floods these can have catastrophic outcomes for the people living along the water body and for economy and infrastructure there.

By the increasing population and trade density in the formerly natural flood plains the potential for damages from floods rises further. After the so-called „Christmas Flood“ in the Rhine river basin in 1993 the damages only for the German part of the territory were estimated to about 0.7 billion Euros. According to Deutsche Rück, the economic losses caused by the Elbe and Danube floods in Germany in August 2002 amounted to more than 11 billion Euros.
Flood protection concepts coordinate beside technical measures also measures for improving the water retention in the catchment area, preventive measures for the protection of uses in flood-endangered areas and measures for the behavior in an acute case of a flood.


Flood protection

Source: Federal Institute of Hydrology (BfG).

Population density 2009

Source: Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBSR)

Validity of the data

A general map on the topic "Flood protection" in Germany can represent only a choice of greater, technical protective measures. Among other things, main points of emphasis of flood protection are reflected in the spatial concentration of protective structures. Selectively, such facilities are depicted in the map that mainly serve the flood protection in Germany. Beside large dams and flood control basins the controllable polders along the rivers are represented, that are in operation since the mid-nineties and that indicate an area-oriented flood management. Selected dyke systems are mapped in the areas along bigger rivers and coastal areas that are endangered by extreme flood events. In large areas the Topographic Map 1 : 50,000 (TK 50) forms the basis for the recorded river and coastal dykes in the Old Federal States. It has to be noted that there is only differentiated between passable and impassable dykes. Also railroad embankments and roads belong to this. In which cases these are structures with pure flood protection function cannot be seen from the TK 50. The “areas endangered by extreme flood events” mark those areas that could be flooded in the case of flood events that occur very rarely. In many areas they are protected by the flood protection.  Numerically model-based determined flooding limits of a flood event of every 50 years were used for the major part of the watercourses.  The polders contained in the map describe areas for controlled water retention (flooding polders). Further information can be found under: and

The population density refers to an area of a municipality. Within the respective municipality there are often more densely and less densely populated areas. In particular cases it can be stated only approximately how many people would be affected by a flood.

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