Federal Inventory of Floodplains of National Importance (FOEN).
Link to the map: map.geo.admin.ch
Since 1850, about 90% of the floodplain areas have disappeared. This is due to river engineering and intensive land use. The riverine floodplains at lower elevations have suffered the most losses.
On the basis of the Nature and Cultural Heritage Protection Act, the Floodplain Ordinance and thus the Federal Inventory of Floodplains of National Importance came into force in 1992. This aims to protect and enhance the most valuable floodplains in Switzerland.
The floodplain inventory distinguishes between five types of floodplain: glacial forelands, alpine alluvial plains, watercourse floodplains, deltas and lakeshores. As of the 2017 revision, the inventory includes 326 objects. A new Annex 2 of the Floodplain Ordinance lists an additional 27 objects that have not been definitively cleaned up. These are protected as a precautionary measure.