Water depths for HQ100 in protected areas

Water depths for HQ100 in protected areas are areas behind flood protection devices (e.g. dykes). The protection devices are geared here to a 100-year flood (HQ100). In rare cases, the protected areas behind it can also be flooded with an HQ100 — for example, when a dike breaks because it stops water pressure or when the groundwater levels rise behind the dike during a long-lasting flood. The color graduation in protected areas is intended to show which depths of water can occur in such a case. It should be noted that in reality, depending on where a protective device fails (e.g. a dike breaks), water depths can also be adjusted that differ from the representation.