Real estate One in six Swiss homes is exposed to natural hazards
Almost one in six residential buildings in Switzerland is located in a zone threatened by natural hazards. This is according to a new study by Zürcher Kantonalbank (ZKB).
08.04.2025, 10:27
SDA
Brienz in Graubünden has already had to be evacuated twice due to a landslide threatening to bury the village. In the summer of 2024, several people lost their homes due to storms in the Misox in Graubünden and the Maggia Valley in Ticino.
As an analysis published by ZKB on Tuesday shows, many homeowners in Switzerland are potentially affected by such events. There are particularly many in the canton of Glarus: almost half of residential buildings are exposed to at least one natural hazard. This is followed by the cantons of Valais (36%), Schwyz (30%), Graubünden (29%) and St. Gallen (27%).
The hazard level is mostly low (62%) or medium (34%). However, every 125th residential building is located in zones with significant hazards, according to the study.
Floods pose the greatest risk
For the study, the threat to residential buildings was evaluated using the hazard maps of 21 cantons. The results show that flooding is by far the greatest threat.
The second most common danger is landslides. These even threatened numerous residential buildings in the canton of Basel-Landschaft, a region where this would not be expected due to the nature of the terrain. The reason for this is the prevailing layers of clay and marl.
However, heavy rainfall is particularly problematic in the mountains, as it can trigger debris flows and landslides as well as flooding.
In Ticino, comparatively few residential buildings are located in endangered zones. However, if they are located in such zones, they are often (46%) at "medium" or even "considerable" risk. This means that the extent of the potential damage could be particularly high. Only the cantons of Valais and Neuchâtel, with around 50% each, have even higher percentages of this risk level.
According to the bank, many risks could be prevented through measures on buildings or protective structures in the terrain, such as flood protection dams, rockfall nets or similar. However, these are associated with considerable financial expenditure. According to ZKB, more than one billion Swiss francs are invested annually in protection against natural hazards in Switzerland.
