Stockacher Aach in Stockach
|Water code||DE : 21592|
|location||District of Konstanz , Baden-Württemberg , Germany|
|Drain over||Rhine → North Sea|
|source||To the northeast of Schwackenreute|
|muzzle||At Bodman in the Bodensee
|Height difference||225 m|
|Bottom slope||9 ‰|
|Catchment area||221 km²|
| Discharge at the Wahlwies gauge (Add.)
A Eo : 195 km²
Location: 10.2 km above the mouth
|252 l / s
758 l / s
1.74 m³ / s
8.9 l / (s km²)
16.6 m³ / s
71.8 m³ / s
|Left tributaries||Mahlspürer Aach|
|Right tributaries||Tobelbach, Krebsbach, Röhretsgraben|
|Communities||Mühlingen , Orsingen-Nenzingen , Bodman-Ludwigshafen ,|
The right upper course Zizenhäuser Aach , officially the main line upper course, rises northeast of the Mühlingen district of Schwackenreute at an altitude of . In the immediate vicinity of the headwaters lies the upper reaches of the Ablach , which flows north to the Danube . The Zizenhäuser Aach initially flows south-east past Schwackenreute and Mühlweiler to around Hoppetenzell , then south through Zizenhausen and Hindelwangen to Stockach .
There, from the east flows, coming Mahlspürer Aach from the left and Zizenhäuser Aach to Stockacher Aach together in a sweeping westward arc Nenzingen , Wahlwies and Espasingen happens or goes through before it between Bodman and Ludwigshafen in Lake Überlingen opens , the northwestern part of Lake Constance. In front of the mouth there is an island with white willows .
The Mindersdorfer Aach, watershed and bifurcation
Today's upper course of the Mindersdorfer Aach is the original, natural upper course of the Ablach. Since the Stockacher Aach has a favorable gradient for the use of hydropower and the sawmills there needed more water, humans first intervened in the natural course of the stream around 1699. In the area of the European watershed between the catchment areas of the Rhine and Danube, most of the water from the Mindersdorfer Aach in the area of today's Schwackenreuter Lake District was diverted into the Stockacher Aach through the Mindersdorfer Aach / Ablach piercing. The water was literally dug up from the Ablach. One speaks here of an artificial bifurcation .
The water of the small Mindersdorfer Aach branches out at the bifurcation and flows westward as the Stockacher Aach into Lake Constance , from where it reaches the North Sea via the Rhine flowing out of Lake Constance . To the north, the water flows as a Ablach into the Danube and takes over this course to the Black Sea . The Mindersdorfer Aach only flows to the Ablach when the water level is high.
With the creation of the Schwackenreuter quarry ponds, the Ablach received a new, artificial stream bed. A weir around five meters long was built in what is now the Aach, which overflows when the water level is appropriate and should give off water into the Ablach. The weir is overgrown with the exception of a trickle (as of 2007), which means that even less water is fed into the drain. This means that the Ablach is only exposed to high tide and largely dries up in the upper reaches during low tide.
The lower reaches and the mouth of the Stockacher Aach were already settlements in the Neolithic and Bronze Age . As was found in archaeological excavations Pfahlbau- and damp soil settlement . The most recent finds at Überlinger See are due to underwater archeology .
Also in the early Iron Age ( Hallstatt Period ) around 700 BC. The lower and upper reaches of the Stockacher Aach were populated. There are numerous barrows . There are also traces of the Celts (4th century BC).
There are various theories about the formation of the Heidenhöhlen near Zizenhausen on a right-hand hill of the Aach tobels below Zizenhausen near Stockach . The eight caves dug into the molasses layer of marl and sandstone could have been living space or a place of worship around the year zero. In 1816, the pastor of Bietingen, Joseph Anton Eitenbenz, who was the first to excavate and describe the Roman Villa Rustica near Meßkirch , found Roman coins . The exact location and type of coin are unknown. The Roman architectural remains found near Orsingen and Homberg prove that the Romans were present in the region . Researchers suspect that along the Stockacher Aach and the upper reaches of the Ablach a Roman road led from the Roman bridge near Eschenz (Switzerland) to the Donaufurt near Laiz (Germany).
Grave finds from the Alemanni period (400 to 800 AD) and place names prove a settlement by the Alemanni after the Roman colonial period.
Numerous castles on hills to the left and right of the Stockacher Aach bear witness to the lively settlement and economic use of the Aach and the Aachtal. For a long time, the Counts of Nellenburg, with their headquarters on the Nellenburg near Stockach, were able to assert themselves against their enemies and expand their domicile.
The tracks of the Hegau-Ablachtal-Bahn run along the Stockacher Aach from Radolfzell to Stockach and further - but now closed - via the European main watershed to Meßkirch , Krauchenwies and Mengen as well as the federal road 313 leading from Stockach to Meßkirch .
- extensive shallow water zone (28 hectares )
- Lower course and mouth of the Stockacher Aach with remains of alluvial forest
- Cultivated landscape interspersed with trees and small reed areas
Shore and shallow water zones are subject to the natural level fluctuations of Lake Constance: from October / November to April / May there is low water. High water levels, at which the silt areas are flooded, result from the snowmelt in the Alps and abundant rainfall in summer.
A total of over 200 bird species have been identified in the estuary. Of these, 52 species are breeding birds. In addition to up to 100 pairs of great crested grebes , the little grebes , red-crested ducks , water rails , kingfisher , reed warbler and oriole breed here . When the Lake Constance level sinks below 350 cm, you can see resting limikoles at migration time . So far 29 species of Limikolen have been identified. In the past these included very rare guests such as avocets , turnstone and Odin's chicken . In September and October, up to 750 cormorants use the trees near the bank as a sleeping place before they move to the Radolfzeller Aach estuary in November . Black-necked grebes , gypsies and golden-bellied ducks can be observed throughout the winter . With a bit of luck, you might see grebes or velvet ducks , which have been hibernating here regularly for several years. Occasionally, other sea ducks are found in winter . Again and again, rarities such as the common loons , black herons , white-tailed eagles and short-eared owls were discovered.
- German Hydrological Yearbook Rhine Region, Part I 2009 State Institute for Environment, Measurements and Nature Conservation Baden-Württemberg, p. 76, accessed on January 22, 2016 (PDF, German, 1.85 MB).
- Alfred Heim: The drainage water also flows into Lake Constance - The small “Rhine-Danube Canal” near Schwackenreute In: Museumsgesellschaft Meßkirch eV (Ed.): Meßkircher Heimathefte. Issue 8 . Born in 2002
- Hydromorphological pressures . In: Water Framework Directive - Inventory. Processing area Danube in Baden-Württemberg. Report . here p. 20