Semi-natural water bodies are home to a multitude of species and are thus extremely valuable as habitats. They are classified into 50 types according to geology, altitude, size and biocoenoses. The "gravel-bed stream" includes the Rhine river between Lake Constance and Leverkusen, the Danube, the upper reaches of the Elbe and Weser and the lower courses of the Main and Neckar rivers. What they have in common is the eponymous gravelly river bed, wide valleys and expansive floodplains of several kilometres in width. In their natural state the large rivers and floodplains form complex aquatic landscapes with an immense diversity, or hot spots of biodiversity. They are crucial migration routes for fish and a offer a resting place for migratory birds.
Settlement building, agriculture, hydroelectric power production and freight transport have left nearly nothing of these aquatic landscapes intact. Only ten to twenty percent of former floodplains still remain. Finally, there are the consequences of restrictive flood protection and chemical pollution.
Real progress in water pollution control and the protection of alluvial areas along the large gravelly watercourses can only be accomplished through joint action by the Federal Government and the federal states (Länder), associations, residents and stakeholders. An example of joint action is the reduction of pollution in Germany's large rivers in the late 1970s due to the construction of sewage treatment plants. Further improvement of ecological condition is expected now and in future from the Water Framework Directive, the national flood protection programme, the Federal Ministry of Transport's programme for the free passage of aquatic fauna in rivers and other water bodies, and the national Blaues Band initiative aimed at renaturing federal waterways and their floodplains.
The regeneration of water bodies needs more space and time. Furthermore, it will become necessary to change the public's perception and interaction with water bodies. Only in extreme rare cases – flooding or low water events – is there any evidence of public awareness of the status of water. The "water body type of the year" campaign is an effort by UBA
to promote the cause of liveable water bodies and the issues of water pollution control. The announcement of the water body type of the year coincides with information campaigns about the special characteristics, aspects of use and risk potential for the selected water body type. An interactive map of chemical and ecological condition are available to learn in greater depth about the world of water.