|Drain over||Traun → Danube → Black Sea|
Seeausrinn , outflow of the Attersee between Schörfling and Seewalchen
|muzzle||between Lambach and Stadl-Paura in the Traun
|Height difference||121 m|
|Bottom slope||3.6 ‰|
|Catchment area||1,261.4 km²|
| Discharge at the Raudaschlsäge
A Eo gauge: 462.9 km²
Location: 33.53 km above the mouth
|1.38 m³ / s
5.59 m³ / s
17.1 m³ / s
36.9 l / (s km²)
56 m³ / s
110 m³ / s
| Discharge at the Fischerau
A Eo gauge: 1,256.1 km².
Location: 1.57 km above the mouth
|2.99 m³ / s
14.4 m³ / s
33.5 m³ / s
26.7 l / (s km²)
252 m³ / s
475 m³ / s
|Left tributaries||Vöckla , Ottnanger Redlbach , Staiger Bach|
|Right tributaries||Drought Aurach , Aurach|
|Residents in the catchment area||approx. 140,000|
The Ager below Schwanenstadt
The Ager is a river in Upper Austria ; it is the outflow of the Attersee and flows into the Traun after around 34 km between Lambach and Stadl-Paura . The Ager drains the entire northwestern Salzkammergut . Its catchment area is around 1260 km².
The Ager leaves the Attersee at its northeastern end between Schörfling and Seewalchen and then flows north through Lenzing . From Timelkam it runs east and takes up the Vöckla at Vöcklabruck . It continues to flow in a north-easterly direction, past Regau , Attnang-Puchheim and Schwanenstadt , until it flows into the Traun as a border river between the municipalities of Stadl-Paura and Lambach.
By far the most important feeder is the Vöckla , which flows into Vöcklabruck. It drains more than 35% of the Ager catchment area. Further tributaries downstream are the Aurach drought near Preising, the Aurach near Wankham , the Ottnanger Redlbach just before Schwanenstadt and the Staiger Bach near Schwanenstadt. Via the Attersee, the Ager also drains the Mondsee , the Zeller See (Irrsee) and the Fuschlsee , each of which is connected by relatively short streams.
Geology and landscape
The Ager was created at the end of the Würm Ice Age , when the mighty Eastern Alps glaciers began to melt. The Attersee is a typical glacier end lake , as well as Mondsee and Irrsee, but they drain in the opposite direction, south to the Attersee, because this transverse breakthrough was created before the lakes could erupt to the north, like the Fuschlsee, which flows over the glacier furrow of the Thalgau , that originated in the confluence area of the Traungletscher and Salzachgletscher . The valley of the Ager itself is in the foothills of the Alps and forms the Vöckla-Agertal valley , which stripes eastward across the Alps. This is surrounded by the Ager-Traun-Terrassenland , post-glacial river terraces in the foreland molasse , and therefore the Vöckla-Ager hill country as a residual landscape . To the south lies the flysch zone , to the north is the sediment mass of the Hausruck .
The mean discharge at the Fischerau gauge is 33.5 m³ / s, which corresponds to a discharge rate of 26.7 l / s · km². The Ager has a very balanced runoff regime , the mean runoff in the month of March with the most discharge (46.7 m³ / s) is only almost twice as high as in the month of October with the lowest discharge (24.0 m³ / s). The natural runoff is influenced by the Klaus weir at the outflow from the Attersee, which is intended to delay the lowering of the lake level in dry periods and to increase the low water of the Ager.
The rich and relatively constant water flow throughout the year favored the settlement of businesses along the river. There were hammer mills and sawmills , grain and paper mills as well as pounding . Seven mills once stood on the upper Ager between Seewalchen and Lenzing alone. In what is now the municipality of Lenzing, wood processing companies and two paper mills subsequently settled. In 1938 the rayon factory was founded in Lenzing, the forerunner of today's Lenzing AG . Up until the beginning of the 20th century, rafting on the Ager also played an important role. Wood from the Attergau was transported to the companies on the Ager and on to the cities on the Danube as far as Hungary.
The Ager is used by several run-of- river power plants to generate energy. The Dürnau run-of-river power plant near Vöcklabruck, which went into operation in 1897, uses a drop height of 4.6 m to generate electricity with a standard energy capacity of 1.9 GWh per year. Seven other small power plants operated by KWG (Wankham 1 and 2, Deutenham, Mühlwang, Kaufing, Hart and Timelkam) together generate around 36 GWh of electricity per year.
The valley area of the Ager is densely populated and characterized by trade, in between there is intensive agricultural use dominated by arable farming. Accordingly, the natural course of the river is severely impaired by weirs, regulations and bank reinforcements. Below Vöcklabruck, the Ager has a more natural, meandering character; here alluvial forest areas have been preserved, some of which (Fasanenau in Vöcklabruck, Schalchhamer Au, Puchheimer Au) are designated as landscape protection areas.
In the post-war period, the Ager was heavily polluted by the industries located on it, including above all the pulp production of Lenzing AG. Today this is no longer the case as several sewage treatment plants have been created. Until the mid-1980s, the Ager only had quality class III to IV, but in 2007 it had quality class I after it drained from the Attersee, otherwise quality class II throughout. As a drainage from several lakes and due to its use as cooling water , the Ager is a relatively warm flowing water for this region with an average temperature of 17.1 ° C in summer and 6.6 ° C in winter.
The main fish species found in the Ager are brown trout , rainbow trout , grayling , aitel and barbel . The unaffected sections of the river and its banks represent an important habitat for various species of birds, such as the common sandpiper , the little ringed plover or the kingfisher . In the floodplains there are bird species such as the goosander and the small woodpecker , as well as numerous amphibian species such as common toad , common frog , agile frog and yellow-bellied toad .
The name Ager is derived from the Celtic Agria . Agria means "drift fast" - a reference to the original strong current of the river.
- The ager in the Atterwiki
- Province of Upper Austria: Fischerau / Ager gauge point ( 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.
- Upper Austrian Room Information System (DORIS)
- Office of the Upper Austrian Provincial Government (Ed.): Ager, Investigations on Water Quality, Status 1991/92 . Water protection Ber. 2/1993, Linz 1993 ( PDF; 8.1 MB )
- Federal Ministry of Agriculture, Forestry, Environment and Water Management (ed.): Hydrographisches Jahrbuch von Österreich 2009. 117th volume. Vienna 2011, p. OG 175 and OG 180, PDF (12.1 MB) on bmlrt.gv.at (yearbook 2009)
- Energie AG: Dürnau run-of-river power station
- Our power plants ( 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.
- Office of Upper Austria. State government: water quality maps
- H. Prinz et al .: Reaction of selected fish species to different water temperatures in Upper Austria rivers , project report (2009), p. 9, ( PDF; 8.5 MB )
- Landesfischereiverband ( 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.
- Office of Upper Austria. Provincial government, nature conservation department (ed.): Nature and landscape - models for Upper Austria. Volume 21: Vöckla-Agertal room unit . Revised Version, Linz and Vienna 2007 ( PDF; 1.2 MB )