Areas liable to flooding; POT Risk Zones

Areas delimited as flood risk areas in accordance with the territorial criteria set out in Annex PN 5 ‘Criteria relating to the Zonification of floodable areas and Admissible Uses’ common to the five Territorial Planning Plans of Navarre (POT). According to the periods of return and draughts, a distinction can be made in: — Low risk area: Areas where floods can be expected with a return period of more than 50 years and a small draught (less than 0.4 m). — Medium risk zone: Areas where floods can be expected with a return period of less than 50 years and a reduced draught (less than 0.4 m), or with a return period of more than 100 years and a draught of more than 0.4 m. — High-risk area: Areas where flooding can be expected with a return period of less than 100 years and a draught greater than 0.4 m. in any case, it shall also be considered a high risk area when the water velocity is equal to or greater than 1 m/s. These layers come from two-dimensional flood studies carried out by the Government of Navarre, as well as from the processing of draught and speed raster data for the different periods of return from the development studies of the National Flood Zones Cartography System (SNCZI) carried out by the Ebro and Cantabrian Hydrographic Confederations (see information sources).