Geneva - Flood areas 2 years return period - Geneva Territorial Information System

Flooding refers to the overflow of a watercourse out of bed. The more or less dangerous nature of the floods depends on the height of water and the strength of the current reached, as well as the amount of material carried.

The determination of the flood zones is relative to the topography. For certain areas, the occurrence of floods depends on the particular conditions that occur during the flood event, such as ice jams under bridges and bridges, the rupture of a protective structure or swirl curves at a confluence of streams or lake.

The return periods for which flood zones have been determined are 30, 100 and 300 years and for some rivers 2 and 10 years. The areas of a conditional flood are representative of the particular conditions described above.