INSPIRE - Flood zones - Overflow Return period scenario 25 years in Wallonia (BE)

This INSPIRE compliant data layer gathers information from the 25-year return period scenario of flood zone overflow.

The data comes from the business data “Flood zones – 25 years return period scenario – Overflow” (https://geoportail.wallonie.be/catalogue/21bf0d97-9752-4d35-8c34-46f719ce92aa.html).

This data is part of the Flood Directive 2007/60/EC. The mapping of flood zones for the 25-year return period scenario is established for the Walloon part of the 4 international river basin districts (Meuse, Escaut, Rhine, Seine). This scenario is requested, if necessary (optional), by the European Flood Directive (ED), or Directive 2007/60/EC of 23 October 2007 on the assessment and management of flood risks, but it is necessary in order to establish a concordance between the 4 scenarios of the IZs and the Flood Alea. It was approved by the Walloon Government on 4 March 2021 (MB: 24/03/2021).
This layer represents river overflow flooding for the 25-year return period scenario (T025), corresponding to a high-probability flood.

When the flood originates in the overflow of a watercourse, it corresponds to an area. It is represented by a height class with possible values of 0 to 30 cm; from 30cm to 1m30 or >1m30. Where this water level is unknown, the water level shall be considered as indeterminate.