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Known as “Lag la Cauma” in the Romansh language, which means “Lake of midday rest”, Lake Cauma is the pearl of Flims. In summer 2016 it was voted Switzerland’s most beautiful mountain lake by the readers of the magazine 20 Minuten. Standing on its shores, we can see to the bottom, so clear and pure is its water. Its extraordinary turquoise-green color is famous, nevertheless the mountain lake remains a mystery.

The origin

The mountain like was formed as a result of the largest landslide in the Alps, which occurred almost 10’000 years ago. The formation of the lakes can be attributed to the prehistoric landslide. The water seeped through the porous rockfall masses. However, it can also dissolve the lime with the help of the carbonic acid it contains. So, over time, it created an underground passage. A deeper impermeable layer of clay ensures that the water does not completely seep into the soil.

The mystery about the water

Lake Cauma at 997 metres above sea level is not only a jewel but also a phenomenon. Guido Casty, tourism executive in Flims, explains that the mountain lake fills up every spring as if by magic, after the other Flims forest lakes “Prau Pult√©” and “Prau Tuleritg” overflow. However, Lake Cauma has neither an above-ground inflow nor an outflow. “The water originates from the karst rock of the Flims mountains. A coherent, underground karst system and groundwater conducting rock formations, so-called aquifers of the Flims landslide, play a decisive role here. What is certain, however, is that meltwater also fills the lake. As a result the level rises with warm weatherand is therefore different every year, depending on the amount of snow of the past winter and the rainfalls. From the end of July to the beginning of August the water level of Lake Cauma is at its highest.”

Since 2003, a remarkably low water level has been observed at Lake Cauma. It is assumed that in addition to the general drought of recent years, the tunnel construction in Flims also plays a role.

Water temperatures

The water temperatures are higher than in other lakes at the same level. The reasons for this are the increase in temperature of the water by 4 – 5 degrees Celsius in “Lag Tuleritg” and a further warming of about 2 degrees Celsius in Lake Cauma due to intensive tanning in the woodland basin and the prevailing calm. Temperatures can vary between 17 – 22 degrees C

Does the water contain healing powers?

In the Flims legends it is said again and again that the water has healing powers. As early as the 19th century, many important guests came to the region to relax, making Flims a health resort. It is said that the water of Lake Cauma accelerates the healing process – especially for skin, eyes and rheumatic diseases. The Flims farmers also believed in the healing water, so that they went to Lake Cauma with their sick animals to bathe them.

Pictures: Foto Geiger, Flims / Martin Flepp, Viaduct

Lyrics: German press release Flims 22nd May 2017, Flimser Brevier / Ernst Wetter- Desertina-Verlag Disentis

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