In Switzerland storms cause damage amounting to approximately 304 million CHF every year (average for the years 1972-2017, taking inflation into account). Since 1972 the Swiss Federal Research Institute WSL has been systematically collecting (based on newspapers) and analysed this damage on behalf of the Federal Office for the Environment FOEN.
Damage originating from naturally triggered floods, debris flows, landslides and (since 2002) rockfalls have been considered. Not considered was damage from avalanches, snow pressure, earthquake, lithening, hail, windstorm and drought. The corresponding weather conditions were also noted in the database. In this way, a database with currently more than 20'000 entries has been generated.
All events since 1972 have caused damage amounting to 14.4 billion CHF (taking inflation into account) in total. The figure below shows that these costs are dominated by a few major events. The event of the 21th/22th of August 2005, with damage amounting to nearly 3,000 million CHF in total, was the most costly flood in Switzerland since 1972.
The database can be analysed in terms of location, extent, causes and the temporal and spatial distribution of the storm events. The results are published yearly in the Journal "Wasser Energie Luft".
The damage data are provided to official institutions on request as a broad information basis for hazard assessment.