After heavy rainfall in recent weeks, Lake Constance has overflowed its banks in recent days. It has reached danger level 4 (high risk of flooding). The last time the lake level was similarly high was in 2016.
The water level of Lake Constance was already significantly above the long-term average of the reference period 1991-2020 in winter and spring.
Caused
is to be found in the record-breaking mild and very wet winter of 2023/2024. In many cases, the snow line was at 1000 to 1500 meters, so that a large part of the precipitation fell in liquid form and immediately drained away.
Intensive snowmelt and heavy rainfall
The intense rainfall, especially at the end of May in the Lake Constance catchment area, and the already saturated soils caused the inflows from Baden-Württemberg and Vorarlberg to rise significantly. On May 31st in particular, considerable amounts fell in north-eastern Switzerland and on the eastern slopes of the Alps. Daily totals of 70 to 100 mm were measured at some measuring stations.
Spatial distribution of precipitation amounts cambodia mobile database on May 31, 2024.
Spatial distribution of precipitation totals on May 31, 2024 (MeteoSwiss)
The Alpine Rhine, the largest tributary of Lake Constance, also carried a lot of water, but the peak discharge remained below 1000 cubic meters per second throughout the entire event. This means that danger level 2 (moderate flood risk) was not reached here. In the Alpine Rhine, it was not the precipitation that played a decisive role in the increased water flow, but rather the very intensive snowmelt over several days.
At the beginning of June, the water level in Lake Constance rose by around 80 centimetres in just four days. Further rainfall from June 9 caused the lake level to rise further.
BAFU blog series in the MeteoSwiss blog
In a series published by the
Federal Office for the Environment (FOEN)
Blogs on the MeteoSwiss website. Today’s blog is a collaboration between the FOEN and MeteoSwiss.
Water level of Lake Constance (FOEN measuring station protect your domain name by choosing lws Bodensee-Romanshorn) from 4 May to 12 June 2024.
Water level of Lake Constance (FOEN measuring station Bodensee-Romanshorn) from 4 May to 12 June 2024. (FOEN)
Lake Constance reached its highest level in danger level 4 (397.31 m above sea level on the Upper Lake near Romanshorn and 397.04 m above sea level on the Lower Lake near Berlingen) on Tuesday, June 11th. Since then, the lake level has been falling very slowly, as a lot of snowmelt water is still flowing in via the Alpine Rhine. The flood situation will therefore only ease hesitantly in agb directory the coming days.
The maximum water level reached on June 11th corresponds to a 10-year flood. The lake level is therefore currently around 1.1 meters higher than the long-term average at this time of year.
Floods in 2016 and 1999 in comparison
At the
flood in 2016
Lake Constance was at a similar level to this year. At that time, the water level in Romanshorn was 397.35 m above sea level, four centimetres higher than this year. At the Untersee, the water level was one centimetre higher this year than 8 years ago. The water level was significantly higher in May 1999. The combination of intensive snow melting after the avalanche winter of 1999