Dornbirner Ach

River course Dornbirner Oh

Dornbirner Ach ( also Dornbirnerach or Dornbirner Ache ) is next to the Bregenzerach one of the main outflow for the smaller streams of the Western Bregenzerwald Mountains and the lower Rhine valley in the Austrian state of Vorarlberg. Until the Rhine Regulation Dornbirner Oh resulted in Fußach in Lake Constance, the name of the village comes from the former names of rivers foot from Oh. Today, about 30 kilometers long river in hardware runs parallel to the Rhine into Lake Constance and crosses the municipal area of the city of Dornbirn.

2.1 Settlement history
2.2 Etymology

3.1 Flora
3.2 Fauna
3.3 obstruction measures

4.1 industry
4.2 recreation area
4.3 drinking Water

Geography

River

The river rises in the so-called Valorsertal (Romansh for bear), on the northwest flank of the High Freschens, near the small mountain village Ebnit, where he still bears the name Ebniterach. The headwaters of the Ebniterach is located in the extreme south of Dornbirn community area close to the border with the municipality of intermediate water. The first section of the river is marked by deep gorges and significant cuts in the mountain landscape of Dornbirn.

Several tributaries, such as the Kobe laughter or Gunzenach, the Ach in the upper course of the river close to. After the blade gorge, from which the river is officially called Dornbirner Oh, it flows through the Alplochschlucht and is dammed to Staufensee. This is named after the mountain Staufen, which rises about. Then it crosses the - in the course of millennia and incised originally developed as a destination - Rappenlochschlucht before it flows past the factories of a former textile factory by approximately 14.5 kilometers in Gütle. The catchment area of Dornbirn Oh to Talaustritt in Gütle with a size of 51.1 square kilometers is one of the wettest areas of Vorarlberg.

Finally they reached a border river between the two Dornbirner districts Hatlerdorf and Oberndorf or later market populated area. At various buildings such as the hospital, the grammar school or the stadium Birkenwiese past it eventually leads back as a border between the districts of Shor and Rohrbach in the Achauen known as a recreational area. Amidst this Laubbewaldung left and right sides of the Ah there is a very special transition possibility over the river, a DISCLAIMER OF ford. In numerous meanders, the river winds below this by the Dornbirner or Loud Ried, where the Koblacher channel opens.

This is the northernmost point in Dornbirn municipality, thus the Dornbirner Oh has the maximum north-south extension in the municipality. In the last section of the river, which from 1904 is straight since Fussach puncture as part of the International Rhine regulation, it forms together with the Old Rhine, the Rhine Delta Nature Reserve. Then the Dornbirner Oh flows parallel to the Alpine Rhine in hardware in Lake Constance.

Inflows

Dornbirner Oh is one of the most important rivers of Western Bregenzerwald Mountains. Many large and small mountain streams, mainly from the Dornbirner municipality (First), feed the river in the first section. Of the numerous left - and right-hand tributaries of the Dornbirner Oh have only a few a name. So here are just the biggest and the most common known. As one of the first ball of the brook flows on the left side in the region of the Lower Wäldlealpe the - to Dornbirner Oh - still known as Ebniterache in this section of the river. The next important left-hand tributary is the brother of Bach, which is considered Ebniter village stream, as it clearly defines the boundaries of the village. Only in the area of Alplochschlucht opens another larger stream, the Late Bach. In the following Staufensee flow numerous short streams, which are hardly longer than a kilometer. The most significant inflow in this first section of the river is the Kobel Oh. These flows over large parts parallel to Ebniter Ache and is called before Gunzen Oh. Furthermore, the Kobel Oh Laubach, Rudach and Tintelsbach flow, before it flows into the Dornbirner Oh in Gütle.

Over a distance of about three kilometers of the Ah flow to rivers, only the left side. Only at the valley station of the cable car opens carts right of Gechelbach. Within the municipal territory of Dornbirn now following does not receive any other streams. Only in the Achauen and the field of Dornbirn and Lauteracher Ried flowing again to small drainage ditches and land. The next important tributary is the Fischbach, which (for example stones Bach, Haselstauderstraße Bach or Karle ditch ) is fed by several rivers in the district and flows until just before the confluence of the Schwarzach and the subsequent, distinctive kink in the course of the river Dornbirner Oh.

The last important river, the Ah on Dornbirner municipality joins, the Koblacher channel, officially called the Vorarlberg Rhine Valley inland canal. This drained large parts of the lower Rhine Valley ( For example, the channel flows of Dornbirn - Lustenau - country trench ) and is next to the Rhine probably one of the most important rivers which run in a south-north direction in the Vorarlberg Rhine Valley. In addition, the inflow of Koblacher channel in the extreme north of Dornbirn municipal area of 405 m above sea level. A. lowest point of Dornbirn. Already in the course of the regulated Oh Lustenau channel about 350 meters flows as the last stream before flowing into Lake Constance to.

Geology

The geography surrounding the Dornbirner Oh is characterized by three distinctive areas. Was first coined by the Lake basin, which has arisen for a tectonically, and by eroding the Rhine glacier in the last ice ages. Second, through the Eastern and Western Alps. Along the Rhine emerges the Helvetic plate under the bottoming out in the Bregenz Forest of the limestone is overlain by flysch. Thirdly and finally, the Rhine Valley, where conditionally much sediment was deposited by the numerous rivers and streams above the bedrock. The alluvial Dornbirner Oh begins with the Talaustritt the river and ends approximately with the first appearance of meanders. In the upper reaches of the Ah flows through mostly powerful but fragile Diluvialmassen, hence the large sediment masses found in the river. The underflow, however, flows through a substrate of Rhine alluvial deposits and own alluvial Diluvionen.

Hydrology

The 51.1 km ² large catchment area of Dornbirn Oh to Talaustritt in the Enz is one of the wettest areas in Vorarlberg, which is itself under the Austrian provinces of the wettest. The steeply rising mountains that limit the Rhine Valley, often result in the prevailing westerly winds able to cool the humid air masses. With the consequent condensation of the steam results in the rain and as often lead to local showers. Nevertheless, there are strong regional differences in precipitation frequency and intensity in a relatively small space. Thus the city of Dornbirn is specified with an average rainfall of 1451 millimeters a year, in Gütle the rainfall is during the same period in 1896 millimeters and in Ebnit it is already 2107 millimeters.

Due to the geographical location, topography and precipitation conditions, the water level of Dornbirn Oh is highly variable and has wild brook -like character. This can be seen quite clearly at the measuring point Enz here the case of low water runoff volume is given with 0.21 m³ / s, the mediocrity is, however, 2.80 m³ / s At high tide, the runoff can swell to 121 m³ / s. This corresponds to an increase in the amount of water by a factor of 576 Also runoff than 200 m³ / s are possible at high water, but are rather the exception. For the case of a flood of the century ( HQ100 ) calculated the hydrologists of Vorarlberg even a flow rate of 300 m³ / s The flow rate of Dornbirn Oh by the State Water Board is 0.5 - given 6 m / s, the average annual runoff of 0.2 billion cubic meters.

Historical

Dornbirner Oh was a natural obstacle that needed to deal with in order to operate the alpine economy in Dornbirn First area can be used for the originally established in the region Alemannic farmers. Later, the river was used for wood pastures. The large fluctuations in the amount of water that have been specified with 1:1000, foresters always put it before a natural problem. It was not until the construction of stone limits on a length of about 2.5 kilometers from the Achmühle to smelters 1830-1834 under upper Wuhrmeister Xavier Fässler protected the surrounding land and dwellings against periodic flooding. Such work Dornbirner population was used as part of the corvee. This construction project was planned by the engineer Alois Negrelli, which at that time (1826 - 1832) was county engineer adjunct for Vorarlberg and still later became known as the architect of the Suez Canal. For construction projects at the Dornbirn Oh was a 19 sheets comprehensive map of the river, drawn by the brother of the famous engineer, Franz Negrelli. This card, with its genesis in 1826, the oldest known representation of the holistic community Dornbirn (excluding the mountain villages ) and probably part of a larger plant for cartographic development of the Rhine Valley. It forms in their detail the basis for numerous research on the settlement geography of Dornbirn.

Also in the 19th century, the imperial military strategists recognized the defense technical possibilities of Dornbirn Oh. So extensive defense plans were designed with reference to the Dornbirner Ah, primarily of importance for the Bodenseeschifffahrt Fussach the port should be protected. In 1899 was commissioned by the textile factory Hämmerle a hydroelectric power plant with reservoir - now known as the power plant level sand and Staufensee - built. This power station was to use the water from Dornbirn Oh for obtaining electric power for spinning in Gütle, today it is owned by the FMV. With the Fussach puncture in 1904 as part of the regulation of the Alpine Rhine Dornbirner Oh was passed into a new bed and opens today at Hard in Lake Constance.

The Alps known as the 2005 flood in the course, torrential downpours in August 2005 damaged the Dornbirner Oh infrastructure facilities such as the Achfurt difficult. Since the 1990s, the city of Dornbirn therefore invested several million euros in the renovation and expansion of the flow restrictor. On 2 July 2008 the city of Dornbirn was recorded in cooperation with the Office of leeway under the term Ah - type 08 the riverbed of Dornbirn Oh of 1,840 kindergarten children and pupils and designed. This action was taken as an opportunity to explain to the children art and nature. The resulting during the day photos were later issued in the country house in Bregenz. On 10 May 2011 a natural event changed the appearance of the famous river section Dornbirner Oh, Rappenlochschlucht sustainably. Around 13:00 clock fell on this day the Rappenloch bridge that crossed the gorge at its narrowest point, with several carrying these rocky parts and spilled as a consequence the Rappenlochschlucht, which until then had been continuously passable on webs.

As part of the flood event in Central Europe in late May 2013, Vorarlberg was once again affected by large amounts of rain, which led to localized flooding and mudslides. Dornbirner Oh led the weekend of May 31 to June 2 at peak flow rates, which corresponded to a 10-year flood event. Apart from the planned flooding of Achfurt but it was served without causing damage along the main arm of Dornbirn Oh.

Settlement history

The first sign of human presence along the river Dornbirner Oh originates from the Bronze Age (3000 BC to 1800 BC ). This is a dagger blade made of bronze, which was found in 1971 with the excavation work for the construction of Achmühlerbrücke. It is also the oldest Fund on today Dornbirner populated municipality. A settlement existed at that time, however, in all probability, not yet. Even from the time of settlement by the Romans, when the whole Vorarlberg area the Roman province of Raetia belonged, no settlements on the Dornbirner Oh are known. Nevertheless, a Roman road, the Via Mala of Mediolanum ( Milan ) to Argentoratum seems to have (Strasbourg ) crosses the Dornbirner Oh. Only in the course of the Alemanni conquest in the 3rd century, the first humans are likely to have settled by the people of the Alemanni in the region of Talaustritts the river. This is indicated by a 1898 found alamannisches grave. Since the Alemanni did not establish individual graves and cemeteries were mostly created in the vicinity of settlements, close historian from this grave Fund on a settlement in the area of today's Hatlerdorfs in the 6th or 7th century.

Finally, around the 9th century, more and more small settlements developed to economically and main traffic junctions along the Dornbirn Oh. So the village Fußach ( Fossonas ) 840 and Lustenau ( Lustenoua ) is first mentioned in the year 887. Dornbirn itself, however, does not appear until 895 as Torrinpuirron. South of the town of Dornbirn Oh Hatlerdorf the villages of Lower Village (market day ) was north of them in the valley and Oberndorf in the hillside. These villages were always to a community and later formed three of the original four districts of the city of Dornbirn.

It was only in the late Middle Ages, the previously used as pasture valley of Ebniterach was also colonized. Impoverished inhabitants of the present Swiss canton of Valais, the so-called Walser, who had emigrated from their original home, built in 1351, the settlement Ebnit on the western slope of the valley. This settlement was a separate municipality until 1932 and was subsequently incorporated into the city of Dornbirn.

Etymology

First, there is the question of what name is used for the etymological analysis. The Austrian Federal Office of Metrology and Surveying defines the name of the river as Dornbirner Oh, so this designation is official and is used for the etymological investigation. In addition, in the years 1960/61, put the Vorarlberg State Government established a number of place names in Vorarlberg and certain the name of the river as Dornbirnerach. This designation is indeed still in use today, but is no longer considered official spelling.

To view the name Dornbirn Oh etymologically, it is split into the two words Dornbirn and Ache. Dornbirn refers to the community, through its municipal area the river flows mostly. The city's name first appeared on October 15, 895 as Torrinpuirron on in a authored in Latin document of the monastery of St. Gall. This word means the courtyards of the Torro Torro which was a resident farmer in the area of present-day Dornbirn (See History of Dornbirn ). The second word - Ache - comes from the Celtic and is related to the Latin aqua and the Low German Aa. The word in the context of a body of water means in Bavarian " fast flowing river or stream with large gradients" (See Ache ). The former name is probably Germanic origin foot Oh, the first time he is mentioned in connection with the named after the river community Fußach in the tax register of the monastery Ragaz in the year 840 as Fossonas. This name evolved over the spellings Fozzaha and Fuozza in the 11th century to Fussach.

Environment

Flora

In the upper reaches of the Dornbirner Oh is a pure mountain stream. This flows through Valorsertal mostly used for alpine farming green areas with lush grass growth. Chance also occur conifers and shrubs. Due to the Alpbewirtschaftung these, however, had largely pasture land to make room for agricultural animals. In the further course of the river, from about the influx of Bach's brother, the river burrows deep into the profile of the mountain landscape and forms part worth seeing canyons. Accordingly, thin here, the biological diversity of plants. Only a few typical shade plants such as moss or lichen brave the inhospitable circumstances at this point. Examples of flowering plants in this section are ordinary dame's violet, Hochstieliger plantain ( Plantago altissima), Columbine and the rare Strawberry Hill.

As of the end of the Rappenlochschlucht, ie in Gütle, the dense coniferous forests of the mountain landscape Dornbirner the banks of the Dornbirner Oh start again to hem. This changes only with the beginning of the urban area, where the natural flora and fauna is initially severely restricted. The entire flow is directed in a concrete river bed through the eastern part of the city. Few shrubs found in this unnatural environment for a new home, the image of the river works here - as is often criticized - artificial and unapproachable. Among the few species that have become established in this river bed, include the silver willow, purple willow, the poplar Canada, the common ash, the sycamore, the hazel, the elm and elderberry.

Below the line, the appearance of the river environment changes very strong and the Dornbirner Oh is fed back into a mostly natural bed with lush deciduous forests left and right. In these woods - the Dornbirn population known as a recreational area - there are no conifers, which strongly resembles the later landscape of the mire. In this Dornbirner Oh flows in strongly meandering. Here it is again largely rich meadows and fields, but there is little arable land, lying on both sides of Ach. The changes to the influence in the Bodensee no more.

The areas of the lower reaches of Dornbirn Oh majority belong to the Natura 2000 sites Lauter Ried and the Rhine delta and the nature reserve Birch - Black stuff - meander Dornbirner Oh.

Fauna

Although the water Dornbirner Oh is very dirty part, but can be found throughout the river fish that have adapted to these conditions and were exposed to the fishing club Dornbirn. Especially in the upper, clean river section and the numerous tributaries there are plenty of fish. There are primarily native species, such as brook trout, rainbow trout, gudgeon, bullhead the loach, live in the water Dornbirner Oh. Furthermore, have been sighted in Valorsertal dragonflies and various salamanders. The strong obstruction in the lower course or in the city of Dornbirn act contrary to the settlement of new species in these areas.

Obstruction measures

Dornbirner Oh applies in addition to the Bregenzerach as one of the strongest torrents in Vorarlberg. This is her not to be considered in the normal case, however, the guided amount of water can multiply within a few hours and the respect to a torrent. Therefore already in 1830 by Alois Negrelli of Moldelbe planned and built in 1834, stone boundary walls have been replaced by modern Betonwuhranlagen that are to avert the danger of flooding from the Gütle. Within the urban area of the flow is directed in a stair-like concrete riverbed. Only below the railway line, these artificial walls are replaced by natural forested earthworks and gravel islands, which take over the flood here. The Torrent and Avalanche Control of Vorarlberg is the Dornbirner Oh known as permanent construction site, as constantly to her or one of its many tributaries must be built. For this purpose, a yard of Torrent and Avalanche Control was set up next to the valley station of the cable car carts.

Use

Industry

If the Dornbirner Oh utilized by the burgeoning textile industry in Dornbirn as an energy supplier nor in the early 20th century, they forfeit its economic importance. Only the power plant level sand, the second oldest power plant in Vorarlberg, which is owned by the FMV, use the Staufensee reservoir the water power of the river yet to produce energy. Because of the permitted water chamfers in the area of forest bath Enz, where the water Dornbirner Oh was still in use until the year 1964 as bath water for industrial use (as Müller Bach known) Dornbirner Oh is theoretically dry, 218 days a year. Practically speaking, however, far less water is taken out as the allowed 1800 liters per second, to protect the flow. In addition, in the upper part of the river the creek Kobe pool is taken in a gravel pit rock in small amounts.

Recreation area

Far more important is the Dornbirner Oh as recreation and tourism area. Here it is primarily the Rappenlochschlucht, which attracts tourists from all over the world. Thank Dornbirnern is known as a recreational area of the lower section of the river in the area of Achauen. Especially in summer, the rocky shores are populated in the artificial stream bed below the saw bridge of relaxation-seeking city dwellers. In 2011, the quality of bathing Dornbirner Oh in urban areas according to the quality guidelines of the Office of the Provincial Government of Vorarlberg was four times as "sufficient" and three as "very good". Originally even the much frequented swimming pool in the Enz was fed by the water of Dornbirn Oh. Only since the reopening of the new forest bath Enz on 24 June 1988, the Achwasser is no longer used in the swimming pool. As part of the revitalization of the city of Dornbirn Achauen created a fitness course and extensive riding and walking trails in the wooded floodplain below the railway line.

Drinking water

At the Dornbirner Ah can be fished with the appropriate license. Drinking water quality ( class I-II) has Dornbirner Oh maximum in the uppermost section of the river, otherwise the quality of the water is generally indicated by the water quality class II. At the latest after the supply of the treated wastewater to the wastewater treatment plant Dornbirn in the area below the Achfurt the water is no longer suitable for drinking and corresponds to the water quality class II -III.

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