Flood water retention
The specialists refer to it as "stabilising water drainage" and "retention". This means permitting the controlled flooding of designated areas to the left and right of the waterway. Land currently used predominantly for forestry and agriculture is structured in such a way that in extreme situations it can serve to protect human lives and material assets along the rivers, without any drastic change of the present land use.
Where broad watermeadow areas accompany the rivers and streams, and additional land is available for this purpose, there is no problem of space. For the densely populated urban areas, where building developments often extend right up to the banks of the river and widening of the water profile is scarcely possible, other solutions are required. Flood retention basins created independently in the course of the river upstream of the urban bottlenecks ensure that flood peaks are buffered long before they reach the cities.
Flood retention basins not only contribute to flood protection, but also lay the foundations for very Special natural spaces to develop here. Largely undisturbed by human activities, near-natural watermeadows can reassert themselves in these retention areas, with small-scale interchange between wet biotopes, wild grasslands and alluvial woodlands.