The regulation of the Danube began in the 15th century and was carried out systematically from the 19th century. The general objectives and disadvantages of river regulation apply to the regulation of the Danube . The most important measure in this context was the regulation of the Danube in Vienna .
Continuous change in the course of the river
Since the formation of the Danube after the unfolding of the Alps and sedimentation of the Pannonian Plain , the course of the Danube changed again and again until the 19th century. Between 1455 and 1870 the course of the Danube in Vienna shifted an average of 20 meters, with the river moving in cycles of 100 to 130 years in the direction of or away from the city. In Machland, today's border between the federal states of Upper Austria and Lower Austria testifies to the mobility of the Danube. Since the border river shifted up to 1 km to the north or south in several places after the border was drawn, the state border in the area of Wallsee now changes several times to the north and south of the state area. In the Danube Delta , the coastline is currently advancing up to five meters per year. The port of Chilia Veche on the Kilija arm was five kilometers from the sea in the 15th century; today it is about 30 kilometers.
Motives for regulation
The first known Danube regulation was not a response to floods. In Straubing , around 1480, the course of the Danube was moved into the 300-meter-long Sossau Bschlacht so that in future the ships should take the route directly alongside the fortified city. This made it easier to control shipping traffic and to collect the lucrative customs duties .
In the 16th century, the first dyke systems were built in the large alluvial basin landscapes of today's Hungary , as well as in Serbia , Bulgaria and Romania , which were then expanded in the 19th and 20th centuries.
In the middle of the 16th century there was no longer enough wood in the alluvial forests in the area around Vienna for the needs of the growing city. Large, well-grown tree trunks that could be used to build bridges and fortresses were in short supply and had to be brought from far away areas in Upper and Lower Austria. After being called to Vienna in 1555, the hydraulic engineer Hans von Gasteiger devoted himself, among other things, to removing obstacles to shipping in the Danube between Krems and Vienna and to making the “Vienna Arm” navigable, which has been known as the Danube Canal since 1703 .
In 1575, Tyrolean miners began removing dangerous rocks from the island of Wörth in Strudengau on behalf of the emperor . However, they encountered disinterest and even resistance from the local population and rulers, who feared for their lucrative piloting business.
The Italian scholar Luigi Ferdinando Marsigli described the entire course of the Danube in a multi-volume work in 1726. His compatriot Johann Jakob Marinoni made numerous maps of the Austrian Danube. In the late 18th century, intensive efforts were made to build flood protection dams and bank protection measures in the vicinity of Bratislava.
In Bavaria , Carl Friedrich von Wiebeking headed the regulation of the southern Bavarian rivers as well as the Danube between the neighboring towns of Lauingen and Dillingen as the royal general director for water, bridge and road construction from 1805 to 1817 .
With the population growth, the resource requirements of the city of Vienna also increased. To supply wood, the construction of the Schwarzenbergsch alluvial canal had already started in 1789 . However, wood from the Bohemian Forest , granite from the Mühlviertel granite quarries and salt from the Salzkammergut had to be transported along dangerous sections down the Danube to Vienna. After the freedom of navigation “in consideration of trade” had been decided at the Congress of Vienna, the most accurate Danube mappings were carried out between 1816 and 1819. The “General Danube Recording” recorded the stretch of the river in Upper Austria, the “Lorenzo Map” for the Lower Austrian section was named after the project manager Christophorus de Lorenzo. The first breakthrough in a river arch was made in 1818 not on the Danube itself, but at the mouth of the Enns . Between 1823 and 1825 the first real Danube breakthrough with a length of almost three kilometers was carried out in the Machland near Au an der Donau . Further punctures followed in 1832 in the "Holler" between Wallsee and Ardagger and in 1836/37 near Fischamend below Vienna. This ensured that Vienna was supplied with building materials for Vienna's Ringstrasse and other construction projects.
In those decades the long stretches of the Danube were also fortified with stone structures. By 1849, 253 km of the banks of the Danube were fixed in Upper and Lower Austria. In relation to the length of the current course of the Danube, around 37% of the banks were paved.
In Hungary, István Széchenyi led the work on the regulation of the Danube and the Tisza. The latter was started in 1846 and described by Florian Pasetti , who, as a member of the Vienna “Danube Regulation Commission”, blocked such plans for Vienna until his retirement in 1868. The first Viennese regulation of the Danube then took place in the years 1870 to 1875.
It was not until 1890 to 1896 that the worst obstacles at the Iron Gate were removed by blasting out around 650,000 cubic meters of rock material. For shipping, however, it remained the most dangerous section of the Middle and Lower Danube until the Eisernes Tor 1 power station was completed in 1972.
During the Danube flood in 1954 , the Danube in Linz reached the highest water level ever measured of 962 cm. As a result, the flood dam, which today borders a large leisure area, and the Swedish settlement in Linz were built. The 21 km long Danube Island was created during the second Viennese Danube regulation between 1972 and 1988 .
The second half of the 20th century was characterized by the construction of run- of -river power plants , which significantly changed the river landscape. The beginning in the Austrian section marked the Jochenstein power plant in 1956 and the Ybbs-Persenbeug power plant in 1959 . At the planned power plant construction in the Hainburger Au below Vienna, however, the political discussions sparked in 1984, which finally led to the establishment of the Donau-Auen National Park , the founding of the Greens and their entry into the National Council in 1986.
The Danube flood in 2002 led to the construction of the Machland Dam , which proved to be a successful measure one year after its completion during the Danube flood in 2013 . Mobile dams have been built in many places, on whose reinforced concrete base metal protective walls can be erected relatively quickly if there is a risk of flooding.
The most important ecological problems in the Danube system today include nutrient inputs , water quality , the interruption of the longitudinal continuum by power plants and large-scale loss of intact floodplain landscapes . The latter is related to the fact that the original length of the Danube was reduced by around 15% as a result of the various regulatory measures.
Various institutions and associations strive to solve the ecological problems. The International Commission for the Protection of the Danube (IKSID / ICPDR) was founded in 1998 with its seat in Vienna, its aim is cross-border cooperation both for the protection and the sustainable use of water bodies and the associated habitats.
Many protected areas have also been established along the Danube.
- List of locks in the Danube
- Danube shipping
- Regulation of Danube tributaries :
- Mathias Jungwirth, Gertrud Haidvogl, Severin Hohensinner, Herwig Waidbacher, Gerald Zauner: Austria's Danube. Landscape - fish - story. Vienna 2014 ( PDF, 63.5 MB at boku.ac.at).
- Floods in Upper Austria in the forum OoeGeschichte.at.
- Danube in the Vienna History Wiki of the City of Vienna (with historical sketches of the course of the Danube).
- International Commission for the Protection of the Danube (ed.): The Danube River Basin District - River basin characteristics. Part A - Basin-wide overview. Short: "Danube Basin Analysis (WFD Roof Report 2004)". Vienna 2005, p. 77, entire article p. 1–192 ( PDF on icpdr.org).
- Christoph Sonnlechner, Severin Hohensinner, Gertrud Haidvogl: Floods, fights and a fluid river: The Viennese Danube in the sixteenth century. In: Water History. 5 (2), Vienna 2013, pages 173–194.
- Friedrich Slezak: Early attempts at regulation in the Danube vortex near Grein (1574-1792). In: The Danube Region. Journal for Danube Region Research. Vienna 1975, pp. 58-90.
- Luigi Ferdinando Marsigli: Danubius Pannonico-Mysicus. Observationibus geographicis, astronomicis, hydrographicis, historicis, physicis perlustratus. The Hague 1726.
- Mario Sommerhäuser, Sabina Robert, Sebastian Birk, Daniel Hering, Otto Moog, Ilse Stubauer, Thomas Ofenböck: UNDP / GEF Danube Regional Project. Activity 1.1.6 "Developing the typology of surface waters and defining the relevant reference conditions". Final report. Essen / Vienna 2003, pp. 1–97 ( PDF on undp-drp.org). Mention of historical maps for river regulation on p. 84: "Allgemeine Donau -aufnahme" (in Upper Austria, 1817-1819) and "Nieder-Oesterreichische Donau-Stromkarte" (in Lower Austria, 1805 from Porta, 1816-1817 from Lorenzo).
- Florian Pasetti: Notes on the regulation of the Danube in the Austrian imperial state up to the end of 1861 with reference to the overview map of the Danube published by the Imperial and Royal Ministry of State. Vienna 1862.
- Water levels (Linz gauge). In: linz.at, accessed on September 25, 2019.
- Sortable list of the electricity companies on the Danube in Austria .