n recent years especially, dams and dykes on
many rivers have proved to be no longer adequate
in withstanding extreme flooding events. In many
cases, they had not been adequately serviced or
upgraded as necessary for a long time, resulting in
ruptures or deep erosion. In view of these very nega-
tive experiences, reviews were undertaken which
widely demonstrated the need to raise or provide
additional sealing for the structures concerned.
Artificial protective structures are essential installa-
tions in populated areas subject to flood risk.
Alongside masonry walls or mobile barriers, earth-
work dykes or dams represent the backbone of tech-
nical flood protection measures.
Retention spaces, such as controllable polders or
flood escape channels, are also barriered by dykes.
By installing inner seals, complete saturation of the
dyke body over lengthy damming periods can be pre-
vented. When structural elements are installed in
those inner shells, the dykes are also able to with-
stand onesided erosion of slope shoulders.