Resin ponds

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Möllerteich near Straßberg

The Harz ponds are smaller artificial bodies of water in the Harz . In addition to the Upper Harz ponds that characterize the Upper Harz , there are also a large number of reservoirs in the Lower Harz . These are often simply referred to as resin ponds. The term is now also in official use. A total of 36 reservoirs were built for mining in the Lower Harz between the 17th and 19th centuries .

General

The entire Harz is, apart from the swamp areas and the southern Harz karst landscape , characterized by the complete absence of still waters of natural origin. Reservoirs were built in the Lower Harz as early as the 14th century, primarily in order to obtain the necessary water for fish farming and the operation of water wheels. The construction of the ponds was intensified in the course of the intensified mining, due to the large amounts of water required as a result, in the 16th to 18th centuries. In contrast to the Upper Harz, the degree of crosslinking is generally low. Mining never achieved the same importance as in the Upper Harz, the deposits were less powerful. In addition, the political and territorial fragmentation of the Lower Harz was not conducive to systematic expansion. In addition to the smaller possessions of larger territorial states (primarily Hanover , Braunschweig and Prussia ), the Lower Harz mainly belonged to Stolbergian , Anhalt and Mansfeld rulers.

Marsh sedge
Basket willow
Fever clover
Rudd

Some of the oldest reservoirs in Germany are located in the middle Lower Harz, the first documentary mentions go back to the year 1320. With the end of mining in the Lower Harz, most of the ponds were no longer needed. The ponds have now become a typical part of the landscape and are home to many, even more rare, animals and plants. Some of these ponds are now classified as dams.

Construction

The 36 mining ponds of the Lower Harz are primarily located in the upper reaches of smaller mountain streams. Due to their construction, they mostly have a relatively large storage capacity. The functionality of the dam systems is not always certain. The maintenance of the ponds is a bit inconsistent in Saxony-Anhalt. The state is responsible for the ponds to be classified as dams (waters of the first order). Maintenance is the responsibility of the Saxony-Anhalt dam operation . The other ponds, as second order waters, are subject to the activities of the respective regional maintenance associations.

For the most part, little is known about the construction of the dams. In 1712 Christian Zacharias Koch took over the management of the Stolbergian mines in Straßberg from Georg Christoph von Utterodt and significantly expanded the water management. Based on his experience in Saxony and Braunschweig, the Unterharzer Wasserregal is likely to be based on the pond construction of the Oberharzer Wasserregal and the Freiberg district waterway.

The dams in the Straßberg area, about which data are available, such as the Untere Kiliansteich , are designed as earth dams with a relatively thin core seal made of turf . For reasons of durability, oak was not used as the material, which is common in mining, but rather oak. For the dam body, material from the surrounding area was used, in the area of ​​the Lower Harz water shelf primarily the characteristic clay slate and greywacke of the Harzgeröder fold zone . The artificial pond in Neudorf was a special feature before its renovation. The seeping water that escaped was collected in open channels and drained away via ditches in the dam apron. The bottom outlet of the ponds was originally designed as a wooden channel and provided with a water-side harrow frame. Dams from around 1900 were z. Some of them are already provided with a cast iron siphon pipe instead of a flume. In the course of the new construction of some pond dams, stone embankments "with a central inner seal made of cohesive earth" were built. Cultivation soil was placed on the air sides and lawn sown. In addition, the renovation of the dam was only partially cut and the old harrow system was replaced by a modern siphon line. As with the upper Kiliansteich , some of the old dam was only covered with a new support structure and raised. In addition, the overflow was designed as a flood relief system with larger dimensions than a concrete structure. Data on the dams away from the Lower Harz water shelf are only available sporadically, but suggest a similar construction method.

nature

Many ponds in the Lower Harz are no longer used economically, except for fishing. Especially the smaller ponds are subject to strong fluctuations in the water level. This created new habitats for many plants dependent on changing water levels. The ponds in the Lower Harz are often more nutrient-rich than in the Upper Harz, but have less water ( lee side of the Harz) and are exposed to longer dry periods.

The ponds are populated by typical plants such as shield water crowfoot , swan flower , resin ragwort , common pond rush , arrow leaf and gray-green willowherb, but also endangered species such as florentine hawkweed , white water lily and water fennel . On the banks of the ponds there are widespread species such as swamp sedge and also endangered species in Germany such as the dwarf hedgehog and pill fern or the summer adonis . The banks and the adjacent wet meadows, which are influenced by the ponds, are populated by plants such as fever clover , real sorrel , water knotweed , beautiful bindweed and mountain knapweed .

The banks of the pond sometimes have typical plant communities in periodically flooded locations. For example, a Strandlings-Nadelsumfsimsen society with a dense border of needle-swamp ridge is typical for the north bank of the Kiliansteich . Other species that occur in it are the fiery and creeping buttercup , limed rush and the skullcap . The rare European strandling and the swamp quendel , classified as endangered in Saxony-Anhalt and Lower Saxony , have already been identified. Very rare plants such as arnica and white moss also live in some ponds. However, many of the ponds are in an ecologically unfavorable condition. The entire macrophyte vegetation consists partly exclusively of water knotweed and / or the floating spawn .

Ecologically important trees such as silver willow , basket willow , lavender willow can also be found on the banks. The dams are populated by a wide variety of plants such as wormwood , pale sheep fescue and common sandwort . The unmodernized pond dams in this case have a closed herb ceiling ( "green dam"), while the renovated often with gravel and Gesteinsgrus are covered.

The fish population is primarily characterized by the fishing clubs that lease the ponds. Are represented, among others, perch , carp , roach , perch , roach , rainbow trout and blue nose . The u. a. in the upper pond at stairs proven bullhead is probably widespread in the ponds and streams feeding and at least in the FFH permanently viable territories, but due to the low density of individuals sensitive to disturbances.

The crayfish , which were almost exterminated by the crayfish plague, still have isolated relict occurrences in some of the reservoirs of the Lower Harz Mountains, which prevents an ecologically fundamentally desirable restoration of the linear permeability of the mountain streams in individual cases - the lack of permeability prevents the disease from spreading. The occurrence in the Krebsbach and Krebsbachteich, which was detected until 1991 , was probably an autochthonous occurrence , but could no longer be detected in investigations in 2009. The deposit probably went out after the floods in 1994.

The reservoirs are important for the great bearded bat as a hunting ground. Rare birds such as the pygmy owl and numerous species of dragonflies, including the blue-winged demoiselle , have also been identified.

For many amphibians specially protected by the BNatSchG , the reservoir ponds have become an important refuge. At the Bärenröder pond alone , well over 3000 migrating amphibians were counted in 1999. Are common to the storage ponds in the catchment area of Selke and Wipper next to the fire salamander and mining , comb , thread and smooth newt , garlic , ground and Northern midwife toad and the endangered yellow-bellied toad . Pond frogs are also widespread . Due to roads with overheated asphalt pavements and high curbs, however, significant losses occur again and again during amphibian migration at some ponds. For ponds in agriculturally used areas, verifiably Bärenröder pond, massive declines in the population have also been observed due to the application of liquid manure to the surrounding fields.

The fishing use of most of the ponds is problematic for the fauna and flora. In addition to high pond population, the use of predators such as eels and pikes is widespread. In addition, the plant communities in periodically flooded locations, especially in rehabilitated ponds, are endangered by the constant water level. The current management does not plan to lower water levels in FFH areas either.

List of ponds

As archaeological cultural monuments , all artificially created historical ponds and ditches in the state of Saxony-Anhalt are protected according to the DenkmSchG LSA , regardless of their age or current function. Only the ponds of the Lower Harz that were formerly used for mining are listed here .

Individual evidence

  1. ↑ a b Christiane Funkel, SELKETAL REFUGE
  2. ↑ State Parliament of Saxony-Anhalt: Draft of a law amending the Budget Act 2010/2011 and the law on the assets "Remediation of contaminated sites Saxony-Anhalt" (supplementary budget law 2011), printed matter 6/507, online (PDF)
  3. ↑ a b c d Karl-Heinz Krause: Development and current function of systems of the historical mining water management in the Lower Harz . In: Wilfried Strenz, Working Group Historical Geography of the Geographical Society of the GDR (ed.): Historical-geographical research in the GDR . Hermann Haack Geographisch-Kartographische Anstalt, Gotha 1986, ISBN 3-7301-0803-4 , p. 143-164 , col. 1 .
  4. ↑ Geology of the Harz ( Memento of the original from October 11, 2012 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.pinatubo.net
  5. ↑ Eckehard Oelke: On the development of the territorial structure in the eastern Harz . In: Wilfried Strenz, Working Group Historical Geography of the Geographical Society of the GDR (ed.): Historical-geographical research in the GDR . Hermann Haack Geographisch-Kartographische Anstalt, Gotha 1986, ISBN 3-7301-0803-4 , p. 127-142 , col. 1 .
  6. ^ A b Wilfried Ließmann: Historical mining in the Harz . 3. Edition. Springer, Berlin 1997, ISBN 978-3-540-31327-4 .
  7. ^ A b c Robert Wouters: Dams in Saxony-Anhalt . Ed .: Saxony-Anhalt dam operation. mdv, Halle (Saale) 2010, ISBN 978-3-89812-677-9 .
  8. ↑ Reason for the land use plan of the community of Südharz preliminary draft 2012  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 7.1 MB)@1@ 2Template: Dead Link / daten.verwaltungsportal.de  
  9. ↑ a b Mine Glasebach Museum
  10. ↑ a b c d European Agricultural Fund for Rural Development: FFH area "Selketal und Bergwiesen bei Stiege" and the corresponding section of the EU SPA "Northeastern Harz foreland", online ( Memento from May 12, 2014 in the Internet Archive ) (PDF) .
  11. ↑ Botanical Working Group North Harz: New finds and supplements to the "New Flora of Halberstadt"
  12. ↑ Biotope Type Guideline of the State of Saxony-Anhalt ( Memento of the original from January 12, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 252 kB)  @1@ 2Template: Webachiv / IABot / www.mlu.sachsen-anhalt.de
  13. ↑ anglermap.de
  14. ↑ Red list of crayfish in Saxony-Anhalt (PDF; 81 kB)
  15. ↑ Great Bearded Bat - Myotis brandtii
  16. ↑ Bird monitoring in Saxony-Anhalt 2004 (PDF; 5.9 MB)
  17. ↑ Flood protection in the Selketal ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF)  @1@ 2Template: Webachiv / IABot / www.rueckhaltebecken-lsa.de
  18. ↑ Gottfried Bürger: On the situation of selected amphibian species in the Lower Harz (Quedlinburg district) . In: Nature Conservation in the State of Saxony-Anhalt . No. 1 , 2000, pp. 15–22 ( uni-frankfurt.de PDF 5.1 MB [accessed March 6, 2014]).