Sarnersee

Sarnersee
Sarnersee
Geographical location	Central Switzerland
Tributaries	Aa , Grosse Melchaa , Kleine Melchaa , Dreiwässerkanal
Drain	Sarner Aa
Places on the shore	Sarnen , Sachseln , Giswil
Data
Coordinates	658 711  /  190440 coordinates: 46 ° 51 '45 "  N , 8 ° 12' 31"  O ; CH1903:  six hundred and fifty-eight thousand seven hundred eleven  /  190440
Altitude above sea level	469  m above sea level M.
surface	7.5 km²
length	6 km
width	1.3 km
scope	15.512 km
Maximum depth	52 m
BFS no. : 9239

The Sarnersee is a 7.5 km² lake in central Switzerland in the canton of Obwalden . It extends in a southwest-northeast direction, is approximately 6 km long and has an average width of 1.3 km. The mean altitude is 469  m above sea level. M. .

location

The lake lies in a wide valley carved out by the ice age glaciers. It is embedded between the mountain ranges of Jänzi (up to 1738 m above sea level) in the north-west and Arnigrat (up to 2105 m above sea level) in the south-east. Its banks are mostly flat, steeper banks are only found on the south corner and in the northwest. The southern tributary of the Sarnersee is the Dreiwässerkanal built in Giswil in 1875, which carries the water from the Lauibach and the Aa (from the Lungerersee ) with it. Since summer 2015, the Kleine Melchaa has also been flowing directly into Lake Sarnen again. Other tributaries are the Steinibach from the west and the Grosse Melchaa from the east, which was diverted into the lake near Sarnen in 1880. Before that, the Grosse Melchaa flowed along the outskirts of Sarnen and only north of Sarnen into the Sarner Aa . The Sarner Aa leaves the lake near Sarnen on the northeast bank.

The three Obwalden municipalities of Sarnen , Sachseln and Giswil have a share of the area in the Sarnersee , with Giswil only having a very small portion in the area west of the mouth of the Three Waters Canal.

history

In the period after the last Ice Age, Lake Sarnen was part of what is now Lake Lucerne . It formed the rearmost section of the Alpnach Bay. In the course of time, however, the Grosse Schliere and the Kleine Schliere as well as the Grosse Melchaa brought in a lot of debris and built up alluvial cones, so that the Sarnersee was constricted and subsequently dammed. Today the lake level of the Sarnersee is 35 m above the Vierwaldstättersee.

Until the opening of Brünigstrasse in 1861, goods and people were transported between the two customs posts on the southern and northern shores of the lake with Nauen .

The last sea ​​frosts (freezing over of the lake) occurred in 1947, 1953, 1956, 1963 and 1981.

fauna

In a study in 2018, 20 different fish species were found in the nutrient-poor Lake Sarnen, mainly perch and whitefish . This corresponds to the historically described population around 1900. In addition, three new, alien species were found: ruff , pikeperch and arctic char . As a special feature, noses were also found, an endangered species of fish which normally lives in rivers.

fishing

Fishing in Lake Sarnen was regulated by old state laws, but basically free. It was replaced by patent fishing in 1878. Commercial fishing came to a standstill at the beginning of the 21st century.

Floods

After the major storm in 1999 and the Alpine floods in 2005 , various projects were proposed to increase the drainage capacity of the Sarner Aa. These ranged from lowering the Sarner Aa to two tunnel projects.

In a vote on September 28, 2014, the Obwalden spoke out in favor of a 6.6 kilometer long underground relief tunnel, which should divert the floods east around the village of Sarnen in the event of flooding. It will begin in the northeast corner of the Sarnersee and flow into the Sarneraa below the Wichelsee . The construction will cost 115 million francs, of which 75 million francs will be paid by the federal government. Preparatory work began in February 2018, a tunnel boring machine is to be used from autumn 2019 and the first part of the project is to be completed in 2023.

See also

• List of lakes in the canton of Obwalden

Web links

Commons : Sarnersee  - Collection of images, videos and audio files

• Niklaus von Flüe : Sarnersee. In: Historical Lexicon of Switzerland .

Individual evidence

1. ↑ ^{a b c d} Seen (Federal Office for the Environment FOEN). Retrieved January 18, 2020 . 
2. ↑ Flood protection Obwalden - Project Kleine Melchaa Website of the building and spatial development department of the canton Obwalden, accessed May 5, 2017
3. ^ Photo «Frozen Lake Sarnen, 1947», in: Katastrophen-Sepp. The Obwalden photographer dynasty Reinhard. Verlag Brunner, Kriens 2001, p. 251.
4. ↑ Snow and temperature (variability) in the Swiss Alpine region (PDF; 2.3 MB)  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , by Simon Scherrer, Federal Office for Meteorology and Climatology MeteoSwiss, from January 22, 2009  
5. ↑ Examining the fish in Lake Sarnen also unearths surprises. In: Obwaldner Zeitung, August 30, 2018
6. ^ Niklaus von Flüe : Sarnersee. In: Historical Lexicon of Switzerland .
7. ↑ Flood protection Obwalden - history  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. Website of the building and spatial development department of the canton of Obwalden, accessed on August 26, 2010  
8. ↑ Variants ( Memento of the original from January 4, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. List of the variants on the website of IG Hochwasserschutz Sarnen, accessed on August 26, 2010 
9. ↑ Obwalden agree to flood tunnels . ( Memento of the original from April 28, 2018 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. In: Obwaldner Zeitung, September 28, 2014 
10. ↑ Canton Obwalden receives 75 million for relief tunnels. In: Obwaldner Zeitung, November 15, 2017
11. ↑ Groundbreaking ceremony for the construction of the flood relief tunnel. In: Obwaldner Zeitung, February 19, 2018