Storm damage in 2020: balance sheet good - protective measures tried and tested

The year 2020 ranks among the ten years with the least storm damage from floods, debris flows, landslides, and fall processes in the 49-year data series. Of the total of nearly 40 million francs, 82% of the damage is due to floods, surface runoff, and debris flows. Damage caused by landslides (10%) and fall processes (8%) was comparatively few. However, their share in last year's total damage was above average, as reported by the Swiss Federal Research Institute WSL writes.

According to the evaluation, most of the damage occurred in the months of June, July, August and October. According to WSL, there were two main reasons for the relatively low amount of damage: On the one hand, there was less damage due to the long dry periods, and on the other hand, technical and organizational measures against natural hazards, which prevented or at least limited damage, proved their worth. 

About half the damage in six days

According to the evaluation, a good half of the damage occurred in the cantons of Ticino and Lucerne and accumulated over just six days. In Ticino, two events caused considerable damage. On June 7, thunderstorm precipitation had led to flooded cellars and roads, especially in the district of Lugano. The consequences of the heavy rainfall of August 28 and 29 in Ticino and in the neighboring areas of the canton of Grisons were much greater, according to the research center. Floods, landslides and rockfalls occurred. In Bissone and Gambarogno, several houses had to be evacuated. In many places there were interruptions and obstructions of road and rail traffic and dozens of people were cut off from the environment.

According to information, the heavy thunderstorms of June 26 and July 1 / 2 led to major damage in the Lucerne area, mostly due to flooding from surface runoff. Masses of water flooded basements, underground garages and road underpasses. In the city of Lucerne, the apartments of an apartment building in the Würzenbach district were devastated by floodwaters from the Gerlisbergbach stream, and traffic was disrupted due to flooded roads. The damage was also considerable in Ruswil, where several streams overflowed their banks, according to the WSL press release.

Protective measures proved their worth

At the beginning of October, low pressure "Brigitte" brought record rainfall over Switzerland. However, in view of the huge amounts of precipitation, the damage was limited. This circumstance is largely due to the proven protective measures against natural hazards and the timely preparation of the emergency services, emphasizes the WSL. In the canton of Uri, for example, the highway was closed and the flooded Reuss river between Attinghausen and Flüelen was diverted to the A2 via the spillway. As a result, the region was spared large-scale flooding. In Diesbach and Bettschwanden (GL), the rapid action of the fire department prevented the debris masses of the rising Diesbach from rolling through the villages. In Locarno, too, the firefighters were prepared and had already evacuated the area near the lake the day before the floods.

A death

Despite all protective measures, not all accidents can be prevented. In October, for example, a person was killed in Finhaut (VS) when his car was hit by a rockfall. This was the only fatality caused by the recorded processes in 2020, as WSL writes in conclusion.

Source: WSL

High loss balance 2021

Only the half-year balance of storm damage in 2021 is already massively higher than that of the entire year 2020. The storms of the last few days have caused damage of around 200 million Swiss francs, according to insurance information provided to the Keystone-SDA news agency. This is the most expensive damage since 2013, they say.  (UP)