Big streaks

Big streaks
Data
Water code	CH : 833
location	Canton of Obwalden ; Switzerland
River system	Rhine
Drain over	Sarner Aa  → Reuss  → Aare  → Rhine  → North Sea
source	above Langis on the Faith Cane 46 ° 53 ′ 36 ″  N , 8 ° 6 ′ 51 ″  E
Source height	approx.  1623  m above sea level M.
muzzle	near Alpnach in the Sarner Aa Coordinates: 46 ° 56 ′ 4 "  N , 8 ° 17 ′ 0"  E ; CH1903:  664 313  /  198 482 46 ° 56 '4 "  N , 8 ° 17' 0"  O
Mouth height	443  m above sea level M.
Height difference	approx. 1180 m
Bottom slope	approx. 77 ‰
length	15.4 km
Catchment area	26.73 km²
Discharge  at the mouth of the A Eo : 26.73 km²	MQ Mq	970 l / s 36.3 l / (s km²)
Communities	Sarnen , Alpnach

The Grosse Schliere (also: Grosse Schlieren , formerly also: Upper Schliere ) is a 15 km long river in the municipalities of Sarnen and Alpnach in the canton of Obwalden in central Switzerland . The body of water takes its name from «Schlier» (in Swiss German schlierggen , German schlieren , slide ), a slippery mixture of marl , sand and gravel, which the designated streams lead.

course

End of the built-up stream bed and transition to Schlierenrüti

Schlierenrüti with changing course of the stream

The Great Schliere rises at around 1620  m above sea level. M. on the Faith Stick in the extensive moorland of the Faith Mountain near Schwendi Kaltbad and above Langis in the municipality of Sarnen. The river forms the border between Sarnen and Alpnach over a length of approx. 4 km. The upper part of the 28.8 km² catchment area is characterized by numerous raised and flat moors. On its way through the Schlierental, which is shaped by the mountain forest, the Grosse Schliere is only exposed to minor human influences. In the lower course the Grosse Schliere flows past Schoried . From here on it is tamed by various barriers due to the large debris loads that occur during floods and the stream bed is built up hard. In Schoried, a small water channel branches off from the river. This Sagenbach flows through the middle of Schoried and Alpnach, where it used to drive a mill and the turbine of a parquet factory.

After the Grosse Schliere has passed under the A8 motorway , the construction ends and the water pours into the wide Schlierenrüti ( Rüti = cleared area), an approx. 450 × 200 meter wetland area of national importance. This also serves as a bed load collector and consists of sand, mud and gravel areas as well as bank vegetation of gray alder, elm, ash and beech with lungwort in the undergrowth. In 1994 over 100 plant species were registered in the floodplain. The channel is very branched in this area, the bottom is permeable and the banks are unpaved. The water quality and the condition of the aquatic organisms are rated as very good at this point.

After the Schlierenrüti, the Grosse Schliere flows into the Sarner Aa about 500 meters below the dam of the Wichelsee . From there, this flows for about 2 km along the Alpnach military airfield until it finally flows into the Alpnachersee at Eichiried .

The entire length of the Great Schliere is around 17 km, the flow rate is on average around 0.8 m³ / s and can swell to over 50 m³ / s in the event of large floods. For rare events with a return period of 10 to 20 years, the maximum discharge is over 100 m³ / s.

bridge

From 1847 to 1948 there was a 50-meter-long, covered wooden bridge over the Grosse Schliere. The builder was the master carpenter Hans Ifanger von Alpnach. At that time he also built the hospital in Sarnen, the church in Hergiswil am See, the monastery in Maria-Rickenbach and the old Hotel Bellevue on Mount Pilatus .

Flood

During the floods in August 2005 , a landslide in the form of a ruff of over 100,000 m³ broke off in the Hurd der Grosse Schliere. Major damage was also caused by the confluence of the Sarner Aa and the Grosse Schliere. Before that, too, there were often floods in the Great Schliere, for example there was a major flood in Alpnach in 1715 with damage up to the church, in 1925 and 1931 the tracks of the Zentralbahn were damaged.

Clock cooperative

The over 100 years old Wuhrgenossenschaft Grosse Schliere dissolved on January 1st, 2011. This numbered 798 perimeter mandatory . From 2011, the tasks of the Wuhrgenossenschaft were taken over by a hydraulic engineering commission from the municipality of Alpnach.

Individual evidence

1. ↑ ^{a b} Geoserver of the Swiss Federal Administration ( information )
2. ↑ Hydrological Atlas of Switzerland of the Federal Office for the Environment FOEN, Table_13
3. ↑ ^{a b} Modeled mean annual discharge. In: Topographical catchment areas of Swiss waters: sub-catchment areas 2 km². Retrieved August 31, 2017 . 
4. ↑ Alfred Helfenstein: The Namengut Pilate territory. Keller, Luzern 1982, ISBN 3-85766-004-X , p. 20.
5. ↑ History of the Schmid-Parkett company ( Memento of the original from October 16, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
6. ↑ ^{a b} Continuous monitoring of rivers in the original cantons - results of the investigation period 2000 to 2003 (PDF; 1.6 MB) ( Memento of the original from October 16, 2013 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. , P. 34, accessed on May 10, 2013.  
7. ↑ Information boards on Schlierenrüti, May 2013.
8. ↑ Intact rivers and streams have become rare (PDF) Media release from the environmental departments of the cantons Uri, Schwyz, Obwalden, Nidwalden and Lucerne, May 2005, accessed on May 10, 2013.
9. ↑ ^{a b} Event analysis 2005 observation network GHO D1, Appendix D Grosse Schliere Alpnach (PDF) ( Memento of the original from May 31, 2012 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. 
10. ↑ Gross Schliere Bridge, Alpnach Dorf (OW) Information on the bridge with numerous photos, on swiss-timber-bridges.ch, accessed on October 7, 2011.
11. ↑ Obwalden history sheets, issue 22, 1998.
12. ↑ Government Council of the Canton of Obwalden: Report on dealing with the flood disaster 2005 (PDF; 350 kB)
13. ↑ Currency cooperatives are a thing of the past  ( page no longer accessible , 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. Article in the ONZ Obwalden and Nidwalden newspaper from April 2, 2011.