Borzelborn
| Borzelborn | ||||
|---|---|---|---|---|
 Borzelborn source near Frankenhain |
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| location | ||||
| Country or region | Ilm district , Thuringia | |||
| Coordinates | 50 ° 44 ′ 38 " N , 10 ° 46 ′ 3" E | |||
| height | 645 m above sea level NHN | |||
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Coordinates: 50 ° 44 ′ 38 ″ N , 10 ° 46 ′ 3 ″ E
The Borzelborn is a spring in the Frankenheim district of the Geratal municipality in Thuringia .
Geographical location
The source is about 2 km southwest of the center of the community of Frankenhain and about 1 km east of the Lütschetalsperre .
General
The Borzelborn is fed from a crevice or overflow source. It emerges on the southeast slope of the Ensebachkopf. The actual source outlet is, however, approx. 60 m further up, on Hugo-Fischer-Weg. At this point, two types of rock meet which, due to the different petrographic rock properties, have a groundwater-conducting or damming effect. Above the source there is quartz porphyry tuff (rhyolithic tuff ), which has an open pore space. In this the water circulates; crevices and rugged areas serve as further transport routes for the groundwater. At the source outlet, the water-filled tuff meets a dense, only slightly fractured quartz porphyry , which is therefore far less permeable to water. Due to these water-retaining rock properties, the groundwater is forced to escape and the spring is created.
In the Rotgende (Oberhof formation; Nesselhof - sediments) of the Thuringian Forest, the boundary between porphyry and tuff is often marked by spring outlets. Some tuff horizons could only be discovered through these sources.
development
The source of the Borzelborn lies on the slope of a road that was originally a raft ditch . This was built from 1691 to 1702. The Alte Flößgraben began with the Langer Grund and Oberer Wiesengrund inlets and led along the slopes of the Borzelberg, Steigers, Eisenberg, Rumpelberg and from there to the Kienberg. The so-called Lütscheflößgraben was extended backwards to the Kehltal a few years later. The purpose of the raft ditch was to bring firewood by water from the remote forests of the former Duchy of Gotha to Luisenthal. At this point the raft ditch then flowed into the Ohra . In 1719, rafting was stopped, whereupon the ditch fell into disrepair and was later partially converted into forest and hiking trails.
The water pouring from today's Borzelborn was previously introduced directly into the raft ditch, whereupon the water flowed directly over the street after the road was built. Between 1920 and 1930, the Jewish intellectual Alfred Berliner vacationed in this area several times with his family and wanted to upgrade this part of the landscape and give his vacation spot Frankenhain a gift. According to his plans and at his expense, a well was built in 1930. On the side, on which the name “Borzelborn” is carved today, was originally the inscription “Dr. Alfred Berliner - Fountain ". After the National Socialists came to power, the name was removed and the Born was renamed "Borzelborn".
In 1964, as part of the construction of the National Front , a steel pipeline was laid from the actual source outlet on Hugo-Fischer-Weg to Borzelborn. In 1991, concrete shafts were placed at the source outlet.
Information about the water
The Borzelborn pours out very soft water with a hardness of 1.0 ° dH total hardness (0.3 ° dH carbonate hardness). As a result, there are only small amounts of metals (cations) and salts (anions) in the spring water. The water is very soft and only very weakly mineralized, as it only flows through volcanic hard rock (quartz porphyry tuff) from which only very small amounts of minerals can be extracted.
Anthropogenic substances that can be carried by environmental pollution are not present in the spring water of the Borzelborn. This is e.g. B. can be seen from the fact that the parameter nitrate , the z. B. can get into the groundwater through excessive use of fertilizers, in Borzelborn with a value of 3.8 mg / l is very low. The influence of sewage faeces can also be read on the basis of microbiological parameters. Such bacteria (e.g. Escherichia coli , enterococci , Clostridium perfringens ) were not analyzed at Borzelborn. Using the parameters “coliform bacteria” and “number of colonies”, however, bacterial influences in the spring water have been detected, which are likely to result from natural processes (e.g. wild population in the spring area or naturally occurring soil bacteria).
The spring only occupies a small catchment area close to the surface , which means that bacteria can easily be transported with the precipitation into the water-bearing quartz porphyry tuffs. Furthermore, the residence time of the spring water in the rock is short (only a few days), which reduces the natural purification of the water as it flows through the rocks.
Source distribution
The source delivers around 0.37 l / s (approx. 32 m³ / d; as of July 9, 2015).