Mangfall
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The Mangfall is a 58 km long left tributary of the Inn in Upper Bavaria . It is the outflow of the Tegernsee and flows into the Inn in Rosenheim .
Geographical
The Mangfall does not arise at a source outlet from the earth, but is the outflow of the Tegernsee , which is fed by several waters of other names; the largest and longest of these at 20.7 km is the Weißach . The river runs northeast to the confluence of the Schlierach on the right , which drains the Schliersee , after which it first moves north-northwest and then north.
At the “Mangfallknie” near Valley , district of Grub, the Mangfall turns its course around 135 ° to the southeast. Here it breaks through the lateral moraine of the former Inntal glacier . Coming from the west, the Teufelsgraben flows into the Mangfalltal, a terrain ditch with hardly any open water, through which the Isar once flowed. Opposite on the Spornberg of the "Mangfallknies" are the remains of the Hungarian Wall Birg .
The largest tributaries of the Mangfall are the Schlierach , Leitzach , Glonn and Kaltenbach (Kalten) . In addition, the Mangfall is fed by numerous small tributaries, but also by source tributaries (especially above the Mangfall knee). Other tributaries include the Schwärzenbach near Louisenthal, the Festenbach (also Moosbach) near Thalmühl, the Steinbach near Thalham, the Moosbach before Grabenstoffl, the Hainerbach in the Vagener Au, the Kaltenbrunnbach in the Aiblinger Au and the Goldbach (also Mühlbach) at Pullach. Since a canal runs for a long distance next to the Mangfall , some of the original tributaries only flow indirectly into the Mangfall. For example, the Feldkirchnerbach at the Wuhrhaus level initially flows into the Triftbach Canal. The water of the Seehamer See , which is partially diverted to the Leitzach power plant, is also discharged into the Mangfall after the Leitzachwerk reservoir.
The eastern part of the Pre-Alps between Isar and Inn is also known as the Mangfall Mountains , as the Mangfall drains the central part of the area through the Rottach , Weißach , Schlierach and Leitzach mountain rivers. This area provides a large part of the drinking water for Munich .
Conversion of the Mangfall for industrial use
The Mangfall was built in the Middle Ages . Initially, mills used water power. In 1810 a salt works was built in Rosenheim to boil the brine coming from Bad Reichenhall . So that enough wood was available, the Mangfall was built for the Holztrift . Numerous diversions were set up from Tegernsee to Rosenheim. The factories made it easier for themselves to drift through the wood with the canals , but they also use the canals to generate energy.
For example, shortly before Bruckmühl , part of the water from the Mangfall is directed into a partially artificially created canal, the approximately 10-kilometer-long Triftbach . This passes through numerous factories and only flows back into the Mangfall at Bad Aibling . The partly nameless Mangfall canals were used almost exclusively for the industrial use of hydropower. In the Kolbermoor municipal area there is an almost dead straight Mangfall canal from the city limits of Bad Aibling, built around 1860 by the Kolbermoor cotton spinning mill , which leads through Kolbermoor to Rosenheim and is partly divided as Stadtbach and Hammerbach. It drives two power plants in Kolbermoor and a power plant in Rosenheim and several smaller power plants in the urban area of Rosenheim am Stadtbach and Hammerbach. Further measures were taken at the beginning of the 20th century for the use of hydropower in the Mangfall, whereby the diversion of the water from the Mangfall, Schlierach (1929) and Leitzach (1919) into the Seehamer See for the operation of the Leitzachwerke should be mentioned. The water collected there is fed through large downpipes to the turbines and caught in reservoirs , whereby a small part of the water above Bruckmühl is fed to the Mangfall and the other part is pumped back into the Seehamer See at night in order to be used again during the day to generate electricity.
These measures raised ecological problems, which led, for example, to fish deaths (insufficient residual water, building up the Mangfall by diversions and straightening, and regulating the flow rate). For some time now, the remaining water levels in the river bed have therefore been increased through tightened approval procedures.
Renaturation of the Mangfall
In recent years, extensive renaturation measures have been carried out at the Maxmühle and in the municipal area of Bruckmühl, Bad Aibling, Kolbermoor and Rosenheim, which are to be expanded continuously . The “falls”, some of which were made of concrete but also of wood to regulate the flow rate, were already showing severe damage due to age.
They were removed from the river and replaced by bed ramps . Above all, this is intended to facilitate the migration of fish again, since fish stocks worth mentioning can only be obtained from the formerly fish-rich waters through stocking measures by the fishing clubs.
In addition, the straightened banks of the Mangfall were modeled again close to nature, creating stage-like structures that cause areas of the bank to be again poor in current . These are the natural habitats for fry and crayfish .
Due to the construction of the tributaries and also the Mangfall, there is a lack of bed load . Geologically, it is feared that the ongoing deepening of the Mangfall river bed could cause the right astable steep bank of the Mangfall (in front of the "Mangfallknie") to slide.
Flood protection
The Mangfall is usually a calm river. After prolonged rainfall in the mountains, in the area of the catchment area there, the Mangfall can turn into a raging river. In the course of history there have been repeated severe floods with catastrophic consequences for the residents along the Mangfall.
The largest flood to date affected the Mangfall in 1899, with a discharge of around 600 m³ / s. A total of 8 km² of now populated area was covered by water at that time. A flood of the century is now only assumed to have a value of 480 m³ / s, whereby a flooding of 3.41 km² of populated area is assumed.
The places on the Mangfall were repeatedly hit by strong Mangfall floods, because even in 1930, 1940, 1946, 1954 and on Whitsun 1999 the Mangfall was threateningly high and flooded, for example. B. parts of the Vagener Au or stepped over its banks at Feldolling .
Such a “flood of the century” devastated large parts of the Bruckmühl market in 1901 , which is why the people living near the Mangfall nowadays have to observe strict building regulations. The house owners, whose properties are in the flood plain, were given the task of securing oil tanks against “floating” in order to minimize ecological damage in the event of a flood. The prices for building land, which are extremely high in the entire Mangfall Valley, have experienced a significant drop in prices when the plots are in a designated risk area.
The flood on 2/3 June 2013, at which peak runoff values of 481 m³ / s and a peak level of 494 cm were measured at the Rosenheim gauge, making it one of the worst floods since 1899.
In recent years, the Bavarian state has planned and implemented extensive flood protection measures that are highly controversial among the population. First of all, a regional planning procedure was initiated which showed that only one of the three alternatives developed by experts met the requirements of regional planning.
Currently (2005) a plan approval procedure is running , which among other things includes raising the dams of the Mangfall. Both the dam crown and drainage pumps are to be built along the dams, which is why extensive land assignments to the state are necessary. In addition, huge open spaces are to be designated as flood plains in the form of polders .
The existing dykes are to be expanded and raised over a total of 33 km. The existing dykes are to be removed over 18 km and a new line is to be implemented. Some areas of the dikes (15 km) are to be dismantled after agreement with the property owners. In addition, a side polder is to be created near Feldolling , which will be flooded during floods.
geology
The Mangfall flows in the tertiary Molasse foothills of the northern Limestone Alps .
In the course of Würm of the formed on the western shore Rosenheimer pelvis , extending through the Inntal glacial had formed, a high moraine the Mangfall from the Tegernsee, at the western edge coming first along flows. During the Ice Age, the Mangfall flowed from today's Mangfallknie through the present-day Grub-Harthausen dry valley further north; From the east, the current lower reaches of the Mangfall flowed through in the opposite direction, also towards the Grub-Harthausen dry valley.
Today the marginal moraine of the Inntal glacier near Grub is broken to the east. The Mangfall achieved this breakthrough in the period of the Young Pleistocene . At the end of the last ice age, when the Inn-Chiemsee glacier had already partially but not yet completely melted (so-called Ellkofener Stadium), the moraine was eroded by a stream that drained into the lower lying glacier basin. After some time, the receding erosion had cut the still barely overgrown moraine so far that the Mangfall was diverted into the lower basin. Due to the fact that the Mangfall initially moves at the western ends of the moraine, and the river has broken down into tertiary layers over the last millennia , a characteristic bank geology results up to Grub.
The right (steep) bank consists primarily of deposits from the Inntal glacier and is relatively unstable. The left bank, however, has produced tufa limestone banks , as spring water outflows have arisen through the incision in the tertiary layers that hold back the groundwater.
Hydrology
The area in which the Mangfall is embedded has an average annual rainfall of around 1200 mm. The southern tributaries of the Mangfall are wild water-like, alpine tributaries, in the vicinity of which annual rainfall amounts of up to 2500 liters per m² fall. The catchment area of the Mangfall is 1099.27 km², the mean flow rate into the Inn is around 17.5 m³ / s (for comparison: the flow rate of the Rott with a similarly sized catchment area is 3.4 m³ / s). The Mangfall is likely to be missing about 7 m³ / s of water here, as this is routed into a drainage of Mangfall water into a utility channel at the level of Kolbermoor , the spinning channel, which in Rosenheim after the art mill is divided into the Rosenheimer Stadtbach and Hammerbach and directly into the Inn flows.
The level of the Mangfall is officially recorded at five points. These are the water levels Schmerold (shortly after the formation), Valley (just before the Mangfallknie ), Feldolling (after the confluence of the Leitzach ), Bad Aibling (after the confluence of the Glonn) and Rosenheim (confluence with the Inn ).
The water level and the flow rate of the Mangfall are subject to extreme fluctuations. During the observation period from 1966 to 1996, only a discharge of 1.02 m³ / s was determined at the Rosenheim gauge on February 1, 1972. On June 18, 1979 it was 389 m³ / s.
The highest water level measured so far in the Mangfall at the confluence with the Inn was measured on July 6, 1997 at a height of around 2.80 m. At the Feldolling gauge on the same day, a gauge of 2.11 m was measured. On May 21, 1999, however, a height of 2.96 m was measured at the same point, but at that time no historical high was recorded at the Rosenheim gauge. This can be explained by the more advanced renaturation measures and targeted discharge of the water into canals.
Biology (flora and fauna)
flora
The flora around the Mangfall is characterized by pronounced ravine forests , beech forests and fens . In addition to extensively used hay meadows, there are also typical alluvial forests along the Mangfall . From a biological point of view, it is a main occurrence of the rough meadows in the foothills of the Alps , whereby the Mangfall represents an axis for alpine and continental species.
fauna
In the case of the fauna of the Mangfall, a fundamental distinction must be made between the fauna in the Mangfall and the fauna in the immediate vicinity of the river.
The Mangfall is a typical body of water in the grayling region . The water habitat is only considered to be moderately polluted with water quality II. The tributaries of the Mangfall are usually not polluted in the headwaters and have an even better water quality, but are already moderately polluted when they flow into the Mangfall .
Currently, the Mangfall located primarily rainbow trout , brown trout , chub (chub), barbel (increasingly) and grayling that Mangfallkanäle play an essential role in their conservation. Barbel occur more frequently from Feldolling downwards. Eels also appear . In the upper regions of the Mangfall there are also minnows , bullheads and other species. Occasionally pike and (very rarely) huchen (2010 catch of a Huchen near Feldkirchen!) Migrate into the Mangfall, as well as noses . Because of the very good water quality, as already mentioned, you can also find crayfish and freshwater pearl mussels in the Mangfall.
The fish find a rich supply of food in the Mangfall. The main insects found are: stoneflies, mayfly larvae, river snails, caddis fly larvae, and the like. In addition to the usual insects, there are also many river fleas whose chitin shell often gives the flesh of the trout a salmon-like pink, which is why many people also believe that there is another subspecies of the trout , the salmon trout , which is however incorrect.
Since summer 2008 the kingfisher can be seen again along the Mangfall, a result of the renaturation measures, which means that the rare animal has an acceptable food supply again.
The local fishing clubs protect the grayling population on the one hand with strong stocking measures, on the other hand with extended closed seasons and / or reduced dimensions . In this context the role of the Mangfall canals is worth mentioning again. In protected sections (especially through old industrial buildings, no approach possible), in which there is no fishing, there are considerable numbers of grayling. With regular stream sweeps (fishing clubs), these are implemented in the Mangfall.
The otherwise common fauna of the foothills of the Alps can be observed in the forests near the river.
Protected areas
The Mangfall flows through several landscape protection areas:
- Protection of the Tegernsee and the surrounding area (LSG-00072.01) in Gmund am Tegernsee up to about 1 km after the outflow from the Tegernsee
- Protection of the Egarten landscape around Miesbach (LSG-00550.01) from Gmund am Tegernsee to the northern city limits of Miesbach
- Protection of the green areas on the Mangfall (LSG-00322.01) in the area of the city of Rosenheim up to the confluence with the Inn
From Gmund am Tegernsee to Unterreit, the Mangfall flows through the Mangfalltal , which is designated as a flora-fauna-habitat area worthy of protection in the Miesbach district and the Rosenheim district .
traffic
The Mangfall itself is not navigable, so it is of no relevance to traffic. In the past, however, it was used to transport trees ( drifting ), which were either made into paper or used as fuel.
As a natural barrier, the Mangfall creates major traffic problems, particularly in the Bruckmühl area . The place only has a bridge in the center. The dense development along the river almost completely prevents the construction of another bridge, which is why crossing the Mangfall in Bruckmühl is a major problem for the further development of the place. A second Mangfall Bridge was completed in 2018. All other places in the Mangfall Valley, however, have had several Mangfall crossings for a long time.
The supraregional road traffic on the federal motorway 8 (Munich – Salzburg) is routed over the 68 meter high Mangfall Bridge near Weyarn .
The Tegernseebahn , the Holzkirchen – Schliersee railway and the Mangfalltalbahn run along the river .
tourism
The entire Mangfall Valley is a magnet for tourists. A cycle path has been created from Feldkirchen-Westerham , which makes it possible to ride the entire stretch of the river to the mouth of the Inn. The picturesque villages on the Mangfall, such as Bruckmühl, attract with their respective sights. Due to the low water level, the Mangfall itself does not offer any opportunities for water sports, but it attracts numerous anglers as it is an interesting " fly fishing area" and entire sections of the route are reserved for this type of fishing. The Mangfall is also popular with summer visitors and bathers, as numerous gravel banks invite you to sunbathe. In addition, there are some hidden and little frequented climbing routes, especially on the upper reaches of the Mangfall. The most famous climbing point on the Mangfall is located below the motorway bridge.
Places and cities on the Mangfall
Individual evidence
- ^ German Hydrological Yearbook Danube Region 2006 Bavarian State Office for the Environment, p. 234, accessed on October 4, 2017, at: bestellen.bayern.de (PDF, German, 24.2 MB).
- ↑ Mangfall drain with Hammerbach
- ↑ Level in the Danube area: Rosenheim / Mangfall ( memento from June 19, 2013 in the web archive archive.today ), from hnd.bayern.de
- ↑ Worst flood since 1899 , from June 3, 2013, on ovb-online.de
- ↑ Great catch in the Mangfall ( Memento from September 4, 2012 in the web archive archive.today ), from kfv-bad-aibling.com
literature
- Wernher Scheingraber, Martin Siepmann (Ed.): To Leitzach and Mangfall. Bayerland, Dachau 1994, ISBN 3-89251-178-0 .
- Klaus J. Schönmetzler, Klaus G. Förg, Kurt Schubert (eds.): Mangfalltal. Edition Förg, Rosenheim 2004, ISBN 3-933708-06-0 .
- Gerd Hedler, Wilhelm Albrecht, Gerd Lottes (eds.): Leitzach and Mangfall . Christians, Hamburg 1983, ISBN 3-7672-0821-0 .
Web links
- Mangfall cycle path , on bayerninfo.de
- Water level Rosenheim / Mangfall , on hnd.bayern.de
- Level: Rosenheim / Mangfall Bavarian State Office for the Environment : Low water information service, on nid.bayern.de
