Opencast mine Borna-Ost / Bockwitz
| Opencast mine Borna-Ost / Bockwitz | |||
|---|---|---|---|
| General information about the mine | |||
| Mining technology | Open pit mine on 15.1 km² | ||
| Overburden | 438 million tons | ||
| Information about the mining company | |||
| Start of operation | 1960 | ||
| End of operation | 1992 | ||
| Successor use | Backfilling to Bockwitzer See (Bockwitz opencast mine), Harthsee (southern part of the Borna-Ost opencast mine), several smaller lakes | ||
| Funded raw materials | |||
| Degradation of | Brown coal / clay | ||
| Degradation of | volume | ||
| Geographical location | |||
| Coordinates | 51 ° 7 '16.5 " N , 12 ° 32' 17.6" E | ||
|
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| local community | Borna , Frohburg , Kitzscher | ||
| District ( NUTS3 ) | Leipzig | ||
| country | Free State of Saxony | ||
| Country | Germany | ||
| District | Central German lignite district | ||
The Borna-Ost / Bockwitz opencast mine was an open - cast mine in the central German lignite district consisting of the two open-cast mines Borna-Ost (1960–1995) and Bockwitz (1982–1992) . It was used to extract lignite and was located east of Borna . After the closure, the Harthsee was created in the southern part and the Bockwitzer See in the northeast part .
Geographical location
The two former fields of the Borna-Ost / Bockwitz opencast mine are located in the Leipzig lowland bay east of Borna. Today the area belongs to the natural mining area south of Leipzig and is located in the area of the municipalities Borna and Frohburg in the Saxon district of Leipzig . The river bed of the Wyhra is located west of the former mining area .
After the area was recultivated , the southern part of the former Borna-Ost opencast mine became the Harthsee and the Bockwitz open-cast mine became the Bockwitzer See. The post-mining landscape is part of the Leipziger Neuseenland . The newly built route of the A 72 between Chemnitz and Leipzig has been located on the western edge since 2013 .
history
prehistory
Lignite had been mined in the area between Wyhra and Eula since the middle of the 19th century . In 1850 test drilling took place next to Gut Bockwitz . At the end of 1852 the Bockwitz mine was opened, in which lignite was mined in civil engineering. First of all, seams II and IV were mined below the Thierbach strata. In the area around Neukirchen and Benndorf , south of Bockwitz, coal had been extracted in deep mining and later in open-cast mining since 1882. In Wyhra , the first open pit mine in the Borna district was opened up in 1897 by the “Grube Wyhra”. In the immediate vicinity of Neukirchen, the first briquette factory was built in the Borna district in 1887. Lignite was mined north of the village. In 1897 the "Neukirchen-Petergrube opencast mine" opened. With the Bubendorfer coal works he partially supplied the Neukirchen briquette factory.
East of the city of Borna, seam IV was mined in six underground and five open-cast mines on an area of approx. 70 hectares by 1950. Opencast mines were u. a. the Rathsgrube zu Kesselshain or the opencast mines “Heine” and “Gottes Segen” in Dittmannsdorf . After mining declined from 1880, the last opencast mine ended in 1918, the last underground mine in 1950. The causes of the closure of the pits were, on the one hand, the charring of the relatively small deposits, and, on the other hand, “drowning” or fires.
Opencast mine Borna-Ost
In the 1950s, the coal reserves in the mining areas west and north of Borna were largely exhausted. The northern field of the Borna-West opencast mine had already been coaled out in 1942; coal was mined in the southern field, which was opened in 1939, until 1970. The situation was similar in the Witznitz opencast mine north of Borna . Production in the Witznitz I opencast mine was stopped in 1949, and the Witznitz II opencast mine was in operation from 1950.
To secure the coal reserves for the refining plants and power plants in the area, the deposit for the “Borna-Ost” mining field was explored between 1954 and 1959. The drainage of the construction site began in 1957 using a system of filters, sections and shafts. Due to the rapid progress of the drainage, the opencast mine was opened in 1960 east of Zedtlitz and southeast of Borna. The first cut already severed the local connection between Zedtlitz and Schönau . The excavated material was collapsed on an outside dump in the Neukirchen opencast mine.
In 1961, mining began in the Borna-Ost opencast mine, which was used to supply the surrounding briquette factories and power stations. This resulted in a seamless transition in the coal supply, since the Neukirchen opencast mine was closed in 1962. By 1963, construction site I had excavated the landscape to the eastern edge of Zedtlitz. Between 1966 and 1968, construction site II of the opencast mine swung clockwise past Borna from the pear outcrop. Subsequently, until 1972 he moved around a pivot point east of Borna towards the south. Between 1966 and 1968, a part of the Borna-Ost settlement with the “Abbey” part of the old town of Borna disappeared. The 134 inhabitants were resettled between 1964 and 1966. Between 1967 and 1971 the Wagnergrund was dredged over a length of two kilometers. The F 176 between Borna and Flößberg was also laid north around the quarrying area at this time, as the old route was excavated. From the south and west, the open-cast mine came very close to the Bockwitz location in 1971/72, but without being dredged over.
Between 1973 and 1979, construction site III was operated around the pivot point north of the opencast mine at Borna-Ost between Zedtlitz and Schönau. It was east of construction site I and south of construction site II, moving clockwise. From 1977, the open pit mine was drained exclusively through filter wells. Construction field IV was operated between 1980 and 1983 with a pivot point south-east of the daytime facilities. During this time, the mining operation swiveled clockwise from the west of the Nenkersdorf location towards Neukirchen in the east. Between 1979 and 1981 the floodplains of Schönauer Bach and Harthbach west of the localities of Schönau and Nenkersdorf were excavated in the first cut. This also severed the local connections from Neukirchen to Schönau and to Nenkersdorf. The area of the Bubendorf opencast mine , which was closed in 1926, was excavated between 1981 and 1983. Its previous swamp took place until the middle of 1980. The former mine workings of the old open-cast mine were also destroyed.
The Borna-Ost opencast mine came to a standstill in 1983 at a distance of 500 meters to the eastern outskirts of Neukirchen. In that year the overburden movement was also stopped, until 1985 the residual coal was extracted. After the tipping was completed, the “Restloch Nenkersdorf” remained in the southern area of construction site IV, which is now known as Harthsee .
Bockwitz opencast mine
As the successor to the Borna-Ost open-cast mine, the Bockwitz open-cast mine northeast of construction fields II and III of the Borna-Ost open-cast mine was opened in 1982. Since 1981, drainage has been carried out using a network of filter wells. The coal, which has been extracted in the excavator-train operation since June 1, 1984, was initially only delivered to the Neukirchen and Thräna briquette factories , later the more distant Borna, Lobstädt and Regis briquette factories were also delivered . The coal extracted came mainly from the Borna main seam (seam II) and the Böhlener upper seam (seam IV).
The overburden from the Bockwitz opencast mine was applied to the dump that already existed from the Borna-Ost opencast mine; it now became the north dump of the new open pit. The floodplains of the Schönauer Bach, the Harthbach and the Wagner- und Mordgrunds were claimed by the opencast mining. In 1985 the southern dump was set up and the dumping of overburden in the disused open-cast mine east began. After the north dump was closed in 1988, the overburden was transported to the inner dump of the opencast mine. In the same year, it was swiveled into the last mining field of the deposit. As a preparatory measure, the village of Bockwitz with its 130 inhabitants and the small settlement "Blauer See" were cleared.
The economic and political change accompanying the German reunification in 1989/90 led to a drastic decline in the demand for lignite, which made it unnecessary to continue operating the Bockwitz opencast mine. Even before the reunification, the decision to stop the open pit was made on April 27, 1990. Already in the same year the cessation of the overburden movement in the 1st overburden cut and the gradual shutdown of the various parts of the operation, such as inner dump, outer dump south and overburden coal cut.
In 1992, raw coal mining also ended. The clay obtained from the Thierbacher layers as an additional raw material during the phase of expiry of the opencast mine was used as a sealing material in landfills. The early cessation of open-cast mining took place at the time when the open-cast mine reached the relocated federal highway 176. The remaining field to the west of the road was to be dismantled by the year 2000, but production was no longer started. When the open-cast mine was closed, the Bockwitz site was no longer dredged.
| Open pit | Start of operating time | End of operating time |
|---|---|---|
| Borna East | 1960 | 1985 |
| Bockwitz | 1982 | 1992 |
Recultivation of the Borna-Ost / Bockwitz opencast mine
The program for the rehabilitation of the Borna-Ost / Bockwitz post-mining landscape was drawn up in 1985 during the GDR era. After the closure of the Borna-Ost opencast mine, this affected the remaining Nenkersdorf hole in the southern area, from which the Harthsee emerged from 1985 onwards through the introduction of marsh water from the Bockwitz opencast mine (until 1993) and rising groundwater. It reached its final level in 1995 and is now used as a swimming lake and local recreation area.
At the time of the closure of the Bockwitz opencast mine in the spring of 1992, there was still a small remnant field prepared for mining. A large part of the areas of the Borna-Ost opencast mine, which was closed in 1985, had already been rehabilitated and prepared for subsequent use. Most of the dump areas of the Bockwitz opencast mine had also been recultivated for agriculture and forestry. In November 1992, the restoration work began on the remaining holes in the open-cast mining area. In addition, six large devices were dismantled, structures demolished and around 52 kilometers of track removed.
The future use of the post-mining landscape envisaged the development of leisure and recreational areas including swimming, and also protected areas for flora and fauna. In particular, the smaller residual water bodies should be preserved and cared for as biotopes. Parts of the redevelopment area in the south and north of the are reserved for leisure and recreational use. In other areas south of the Bockwitzer See and in the area of the remaining holes, the main water drainage and the southern tip, a coherent area was created that was reserved for the undisturbed development of nature and landscape.
The rise in groundwater began with the shutdown of the main water drainage system in 1993. Due to the isolated location of the two opencast mines, flooding by external water and the relatively rapid rise in groundwater was not planned. In ten years, bodies of water of different sizes were created on the area, which were intended for various uses. Among other things, these were the main remaining hole Bockwitz and the smaller remaining holes Südkippe, main water drainage and the wetland. The Bockwitzer See emerged from the main remaining hole and reached its target water level in 2004 with 170 hectares. For technological reasons, the former dam drainage at the southern tip of the lake had to be separated by an earth dam. This area was partially flooded at the end of 2005.
The remaining holes of the main water drainage and the southern tip between the Bockwitzer and the Harthsee were flooded from 1993 solely from the natural ground and surface water inflow. The remaining 18 hectare main water drainage hole reached its final water level in 2004. The 31 hectare remaining southern tip hole reached its final water level in 2001. The remaining 12 hectare wet biotope hole was completely flooded in 2002. All three lakes are reserved for nature conservation.
The Blue Lake near the former location of Bockwitz was dried out as part of the lowering of the groundwater level in the Bockwitz open-cast mine. Today it is located northwest of the Bockwitzer See and fills with water again with the regenerating ground and surface water levels. After the trap has been put into operation, the excess water from the Bockwitzer See is drained via the Saubach to the Eula .
Output of the opencast mines
The mining area of the Borna-Ost and Bockwitz opencast mines covered an area of 1,510 hectares. 109 million tons of coal were extracted and 433 million cubic meters of overburden moved.
| Open pit | Land claim | Raw coal mining | Overburden movement |
|---|---|---|---|
| Borna-East (1960–1985) | 1,272 hectares | 98.2 million tons | 354.6 million cubic meters |
| Bockwitz (1982-1992) | 238 hectares | 10.8 million tons | 83.4 million cubic meters |
From 1978 to 1990, the filter well-Randriegel Ost supplied a total of 46 million cubic meters of water to the Prießnitz waterworks , which also served to feed the Harthsee. In the area of the Borna-Ost and Bockwitz opencast mines, around 100 to 125 filter wells were operated together up to 1990, from which around 6.5 million cubic meters of water were pumped per year.
Relocated places
| Relocation site | Residents | Year of relocation |
|---|---|---|
| Borna -Est with settlement Abtei | 134 | 1964-1966 |
| Bockwitz with the "Blauer See" settlement | 130 | 1988 |
Web links
- Description of the opencast mine Borna-Ost / Bockwitz in a PDF document from the LMBV
- The opencast mine Borna-Ost / Bockwitz on www.devastiert.de
- The Bockwitz opencast mine on www.ostkohle.de