Technical flood protection due to the construction of dikes, protection walls, retention basins or reservoirs to protect settlements remains indispensable, even though effects are only and may increase floods downstream.
However, technical protection measures for settlements only seemingly convey security. If kept in a secure state, they only protect man and his goods to a planned upper limit, which may always be topped by extreme floods. If this limit, the so called design flood is topped, damages behind the flooded dikes tend to be extremely high. Thus, according to the Action Plan on Floods, the damage potential (buildings, roads) in vulnerable zones must in no case be increased.
The last flood events demonstrated that failing overall stability in particular of older dikes presents a high risk and that the required restoration requires great amounts of money. Before beginning with dike restoration, the possibilities of dike relocation and thus gaining back additional overbank areas should be looked into.
that technical protection measures for settlements only represent apparent security?