Mad lake

This article deals with a lake in Upper Austria, for a market in Ostallgäu see Irsee .

Irrsee Zeller See / Zellersee
Irrsee seen from the balloon
GKZ	AT / HZB: 2-122-152-001-016, OWK: 4500100, WFD: AT315000710021
Geographical location	in the Salzkammergut
Drain	Zeller Ache
Places on the shore	Zell am Moos , Laiter (municipalities: Oberhofen am Irrsee , Zell am Moos , Tiefgraben )
Data
Coordinates	47 ° 54 '44 "  N , 13 ° 18' 25"  E Coordinates: 47 ° 54 '44 "  N , 13 ° 18' 25"  E
Altitude above sea level	553  m above sea level A.
surface	3.548 7  km²
length	4.7 km
width	1 km
volume	53,000,000 m³
scope	11.2 km
Maximum depth	32 m
Middle deep	15 m
Catchment area	27.5 km²

The Irrsee or Zeller See (also Zellersee ) is a lake in Upper Austria , near the border with Salzburg . It is the warmest lake in the Salzkammergut and is a nature reserve .

The Irrsee lies at an altitude of 553  m above sea level. A. and is a good 4½ km long. and 1 km wide. Together with the Fuschlsee , it is the uppermost larger lake in a chain of lakes in the Salzkammergut , which continues over the Mondsee to the Attersee .

The Irrsee is relatively natural and, together with the surrounding moors, offers a habitat for many endangered animal and plant species. It reaches temperatures of up to 27 ° C and is considered a good bathing lake , but is much less visited than the other large lakes and has a comparatively gentle tourist infrastructure.

geography

The Irrsee lies in a depression of the flysch zone that runs in a north-south direction and is surrounded by glacial moraines . The elongated lake basin has an approximately rectangular shape. The west bank is steeper than the east bank, the north and south banks are very flat. West of the Irrsee is the Kolomannsberg . Zell am Moos is located on the east bank and the entire lake area belongs to the municipality. The municipality of Oberhofen am Irrsee connects to the north and the municipality of Tiefgraben to the south .

The lake consists of a smaller, 27 m deep northern basin and a larger, 32 m deep southern basin, which are separated by a ridge at a depth of 21 m.

The Irrsee is fed by more than 20 smaller streams and submarine springs and flows over the Zeller Ache to the south-east located Mondsee. The mean discharge is 1.3 m³ / s, the theoretical water exchange time 1.3 years.

Because of its low volume and sheltered location, the Irrsee regularly freezes over, and the duration of the ice cover can vary between a week and two months.

Emergence

In the Ice Ages, the Attersee-Mondsee basin was covered by the mighty Traungletscher like the area of ​​the other Salzkammergut lakes today . This sometimes formed deep troughs, called tongue basins at the ends of the glacier . The Irrsee was probably formed around 17,000 years ago towards the end of the Würm Ice Age , when the Traungletscher retreated and the tongue basins were filled with meltwater. The silting areas with moors and wet meadows in the north and south indicate that the lake was almost twice as long at the end of the Ice Age as it is today.

environment

The banks are largely undeveloped and natural, they are in large sections surrounded by a belt of reeds, silting bogs and wet meadows .

Zellersee and Irrsee Moore nature reserves

Irrsee-Nordmoor

The entire lake area is protected as a nature reserve Zellersee (Irrsee) with 349.1935  hectares ( N018 ). The lake has partly good reed belts . A lakeshore protection zone of 500 m has been set up at the Irrsee , and parts of the surrounding moor meadows are also under nature protection, the Irrsee-Moore nature reserve  ( N109 ) with 52,0004 hectares.

• the Irrsee-Nordmoor , a mud sedge with alder break
• the Laiter-Moos at the Moosmühle bathing area in Laiter on the northeast bank, a Davallseggenried
• the Grabenmoos around the Grabenbach between Graben and Ramsau
• the Zellermoos near Zell am Moos , a smaller remnant of a Steifseggenried
• and the moss meadows on the Irrsee south bank , north of the bathing area, the runoff moss on the Zeller Ache , as well as on the Iltisbach and at Gasthof Pöllmann on the south-west bank, transitions from Steifseggenried to economic meadows

Water quality

The depth of view is temporarily influenced by mineral turbidity, biogenic decalcification and phytoplankton. From around 1985 onwards, as a result of the renovation efforts, the water quality has improved in all parts of the lake. Today it is classified as oligotrophic to oligotrophic- mesomorphic , the mean visibility is 5.0 m.

Flora and fauna

In the silting areas and wetlands, there are many low-growing Sedges as Alpine hair rush , head rushes or Davall sedge and purple moor-grass meadows , where next to the moor grass u. a. Bloodroot , swallowwort gentian or real betonia grow. In the north moor of the Irrsee there are small ponds with significant stocks of pond roses and water lilies .

The main types of fish that occur are pike , puree , carp , tench , bream , eel , pikeperch , catfish and aitel .

The moors and wet meadows around the Irrsee are important habitats for numerous specialized and endangered animal species. There are several insect species tied to humid habitats, such as the marsh insect , the moor meadow bird or the little blue arrow . Numerous species of birds also have their - z. Sometimes the only breeding area in the country, especially the curlew and the whinchat .

use

The south bank of the Irrsee, in the foreground part of the sculpture "Phyllotaxis-Irrsee"

Due to the relatively high water temperatures in summer, the Irrsee is a popular bathing lake. On its banks there are several bathing beaches (especially in Laiter on the northern east bank, in Zell am Moos and at the southern end in the community of Tiefgraben) and camping sites. Large sections of the bank, especially on the west bank, are private bathing areas (the rest of the bank is inaccessible as a nature reserve and is boggy or reed). The bathing water quality is excellent (blue according to GZÜV), in some years, especially with little fresh water inflow in dry summers, only good (green).

Fishing also plays an important role. When the ice cover is stable, the lake is used by ice skaters and curlingers in winter.

As part of the Mondsee Land Art project, two works of art were installed on the banks of the Irrsee in 1999. At the bathing area in Zell am Moos was the tilted area of Benoît Tremsal . On a hill on the south bank is a sculpture by Sjoerd Buisman , Phyllotaxis-Irrsee . It represents the section through the leaf stand of a celery stalk, which is supposed to remind of the shape of the lake shore.

literature

• Hubert Gassner: The fish biological and limnological development of the Irrsee. In: Heimatbuch Irrsee , 1 Natur & Umwelt , pp. 64–69 ( PDF , baw-igf.at).

Web links

Commons : Irrsee  - collection of images, videos and audio files

• Austrian Agency for Health and Food Safety : Bathing waters: Irr- or Zellersee: Laiter , Tiefgraben , Zell am Moos - current quality assessment
• Province of Upper Austria: Zellersee nature reserve (Irrsee)
• Province of Upper Austria: Irrsee-Moore nature reserve

Individual evidence

1. ↑ ^{a b} The two names are so equivalent to each other in the area that the terms Zeller- or Irrsee and Irr- or Zellersee are also found very often in specialist literature. On site Irrsee used slightly more often to confusion with the more famous Lake Zell excluded from Zell am See in Pinzgau.
2. ↑ ^{a b} Information on DORIS , subject of water and geology , in particular information on detailed catchment areas and reporting water network , doris.ooe.gv.at
3. ↑ ^{a b c d e f} Federal Office for Water Management (Hrsg.): Atlas of the natural lakes of Austria with an area ≥ 50 ha. Morphometry - Typing - Trophy. As of 2005. Series of publications by the Federal Office for Water Management, Volume 29, Vienna 2008 ( PDF; 9 MB )
4. ↑ ^{a b c} After the Riedelbach it represents the second section of the main line in the catchment area of ​​the Ager , up to its confluence with the Traun it is hydrographically a good 80 kilometers of flow path. Lakes are not measured in a completely straight line, but along main axes in the river bed. The Irrsee is stationed at around 4.9 kilometers from km 80.40683 to 75.52143 , the length of the lake north – south is only 4.7 km along the regular water limit;
   DORIS information, information on main reporting waters and detailed water bodies .
5. ↑ ^{a b c d e} Office of Upper Austria. State government (Ed.): Potential study Salzkammergut. Ecological condition and opportunities for improvement at the Mondsee and Irrsee tributaries. Water protection report 44, Linz 2011 ( PDF; 9 MB )
6. ↑ ^{a b c d} Office of Upper Austria. Provincial government (ed.): Nature and landscape / models for Upper Austria. Volume 12: Attersee-Mondsee basin spatial unit. Revised Version, Linz 2007 ( PDF; 4.6 MB )
7. ^ Roland Schmidt: Lakes and moors of Upper Austria as archives of vegetation and climate history. In: ÖKO.L magazine for ecology, nature and environmental protection. Volume 3, Issue 3, Linz 1981, pp. 6-8 ( PDF (823 kB) on ZOBODAT ).
8. ↑ D. Achleitner, H. Gassner, A. Jagsch: The limnological long-term development of the Mondsee and Irrsees . In: Selected results of the INTERREG IIIA project “SeenLandWirtschaft”, Volume 26 of the series of publications by the Federal Office for Water Management , 2007, pp. 3–17 ( PDF; 6.9 MB ( Memento of the original from December 19, 2015 in the Internet Archive ) Info : The archive link was inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this note. , Baw-igf.at) 
9. ↑ ^{a b} OGW: Seeprofil Irr- or Zellersee. Inspection according to GZÜV (Waters Condition Monitoring Ordinance - Federal Law Gazette II No. 479/2006). Status: October 2013 ( pdf ( memento of the original from December 8, 2015 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , Land-oberoesterreich. gv.at). 
10. ^ Upper Austrian State Fisheries Association: Zeller- (Irr-) See
11. ↑ Mondsee Land Art , forumk.dasmondseeland.at (PDF; 840 kB)
12. ↑ Information board by the sculpture , photo (Wikimedia file)