Upper Harz Ponds

Ponds near Buntenbock south of Clausthal-Zellerfeld: the Ziegenberg Pond (front) and Marsh Pond (Sumpfteich, rear). Their dams are clearly visible.

The Upper Harz Ponds (German: Oberharzer Teiche) are found mainly around the mining town of Clausthal-Zellerfeld and the nearby villages of Buntenbock and Hahnenklee in the Upper Harz mountains of central Germany. There are around 70 ponds in total, both large and small. They were built by the miners of the Upper Harz, mostly between the 16th and 18th centuries, and are important components of the cultural monument known as the Upper Harz Water Regale - a network of dams, ditches, ponds and tunnels that was built to supply much-needed water power for the mining industry in the Harz mountains. Today the Water Regale is being proposed as a UNESCO World Heritage Site. About half the dammed ponds are classified today as reservoirs, but they have now become characteristic features of the Upper Harz and are home to some extremely rare plant and animal species.

The Upper Harz Ponds also have the oldest working dams in Germany.

Purpose

The dam of the Great Crane Pond (Großer Kranicher Teich) near Hahnenklee. The bottom outlet can be operated from the control hut.

The ponds were originally built for storing the water needed to drive the water wheels providing energy to the Upper Harz silver mines. These water wheels drove the pumps, the hoisting equipment, the stamp mills and, from 1820, the man engines as well.

To begin with, the ponds merely impounded water from their natural catchment areas. But in many cases, their inflow was later increased significantly through the use of additional collection ditches.

Today the ponds are operated for several reasons: the protection of historic monuments, rural conservation, nature conservation and recreation. Several ponds also provide flood protection; others are used to supply drinking water.

The operator of the ponds today is the Harzwasserwerke, who also manage six modern dams in the Lower Saxon part of the Harz.

Design

The barriers were built as earth-fill dams, the fill being usually excavated on site. Usually small quarries were established in the terrain earmarked as the future reservoir; this had the added advantage that it increased its eventual capacity. Neither clay nor silt could be used as grouting material because they did not occur in sufficient quantities in the Upper Harz. The Upper Harz miners had, however, learned from experience that grass sods or turves made excellent grouting; by placing them one on top of another, in a similar fashion to building a wall, a layer of sods up to a metre thick would be built into the dam which ensured that it remained watertight.

A wooden conduit (Holzgerenne) acted as a bottom outlet. It was usually made of oak due to its great durability. The valve was a so-called Striegel, which acted like a plug and closed off the inlet to the wooden channels and was operated by rods. Both grass sod grouting and wooden bottom outlets are still in use in many of the ponds.

The dams themselves are between 4 and 15 m high and the impounded volumes varied between 10,000 and 600,000 m³. One notable exception is the Oderteich northeast of Sankt Andreasberg, which is the only pond not grouted with grass turves, but with granite sand known as granitgrus and with a dam height of 21 m and reservoir volume of 1.7 million m³ of water stands head and shoulders above the other ponds in terms of size.

Flora and fauna

Crayfish
Strapwort in the autumn

Although these water features have been artificially created, rare flora and fauna have evolved in and around many of the Upper Harz ponds. The water is low in nutrients and rather cool. The crayfish, which has died out in most European waterbodies due to crayfish plague, has been able to survive in many Upper Harz Ponds thanks to their isolated locations. Pond operators and fishing leaseholders have worked successfully to increase their numbers.

The operation of the ponds over many centuries with constantly changing levels of water has also created a habitat for some extremely rare plant communities. On the soils of many ponds coral necklace (Ilecebrum verticillatum), strapwort (Corrigiola litoralis) or shoreweed (Littorella uniflora) may be found growing. They are dependent on this constant fluctuation of water levels in the reservoir and so the nature conservation authorities have agreed with the pond operators an operating regime that will secure the existence of these plants in the waterbodies concerned. By other ponds there are meadow bogs (Kleinseggenried), which are rich in sedges, rushes and cottongrass and moss communities.

The fish population is primarily influenced by the angling clubs that lease fishing rights and stock the ponds with fish. Only native species of fish are desired, although eel and catfish are excluded due to their incompatibility with the crayfish populations.

Table of Upper Harz Ponds

The Smelter Pond (Hüttenteich) near Altenau
The dam of the Middle Kellerhals Pond north of Zellerfeld is around 15 m high and can impound up to 436,000 m³ of water.

The following list includes the majority of the dammed ponds built by the Upper Harz miners, where they are still in operation or where the dam ruins are still clearly visible. Mill ponds are not included. A total of 143 dams and former dams have been documented.

English Name German Name Built Capacity in m³ Height above base in m
Old Sandpiper Pond Alter Wasserläufer Teich before 1565 32,000 5.30
Capercaillie Pond Auerhahnteich 1684 61,000 7.74
Bärenbruch Pond Bärenbrucher Teich before 1634 186,000 7.09
Carl Pond Carler Teich 1673 14,000 5.10
Upper Einersberg Pond Einersberger Teich, Oberer before 1672 140,000 9.16
Middle Einersberg Pond Einersberger Teich, Mittlerer before 1672 16,000 7.74
Lower Einersberg Pond (†) Einersberger Teich, Unterer (†)
Duck Marsh Entensumpf
Highest Eschenbach Pond (†) Eschenbacher Teich, Oberster (†)
Upper Eschenbach Pond Eschenbacher Teich, Oberer 1548 62,000 10.50
Lower Eschenbach Pond Eschenbacher Teich, Unterer 1548 167,000 8.85
Eulenspiegel Pond Eulenspiegler Teich around 1546 61,000 3.43
Upper Flambach Pond Flambacher Teich, Oberer 1701 88,000 6.50
Lower Flambach Pond Flambacher Teich, Unterer 1693 48,000 5.03
Upper Raft Pond Flößteich, Oberer before 1680 11,000 5.00
Lower Raft Pond Flößteich, Unterer before 1680 10,000 4.28
Flöß Pond (Piß Valley) (†) Flößteich, (Pißtal)
Fortune Pond Fortuner Teich 1721 296,000 14.33
New Grumbach Pond Grumbacher Teich, Neuer after 1714 108,000 8.67
Upper Grumbach Pond Grumbacher Teich, Oberer before 1680 180,000 10.50
Middle Grumbach Pond Grumbacher Teich, Mittlerer after 1680 72,000 9.20
Lower Grumbach Pond Grumbacher Teich, Unterer before 1680 82,000 7.52
Haderbach Pond Haderbacher Teich before 1693 103,000 9.43
Upper Hahnebalz Pond Hahnebalzer Teich, Oberer before 1695 66,000 8.11
Lower Hahnebalz Pond Hahnebalzer Teich, Unterer 1676/86 52,000 6.50
Hasenbach Pond Hasenbacher Teich 1660 140,000 9.12
Hare Pond (†) Hasenteich (†)
Upper Hausherzberg Pond Hausherzberger Teich, Oberer 1588 180,000 7.18
Lower Hausherzberg Pond Hausherzberger Teich, Oberer before 1613 198,000 9.35
Haus Sachsen Pond Haus Sachsener Teich
Herzberg Pond (Goslar) Herzberger Teich (Goslar) around 1560 95,000 12.00
God's Help Pond Hilfe-Gottes-Teich before 1763 12,300 8.30
Stag Pond Hirschler Teich before 1671 599,000 11.40
Smelter Pond, Zellerfeld Hüttenteich, Zellerfeld before 1673 13,000 6.42
Smelter Pond, Altenau Hüttenteich, Altenau 1688 49,000 11.73
Huttal Pond, Upper (†) Huttaler Teich, Oberer (†)
Huttal Pond, Lower (†) Huttaler Teich, Unterer (†)
Jägersbleek Pond Jägersbleeker Teich around 1670 380,000 13.65
Johann Friedrich Pond Johann-Friedricher Teich 1674 96,000 6.79
Carp Pond (Hahnenklee) (†) Karpfenteich (Hahnenklee) (†) before 1680
Upper Kellerhals Pond Kellerhalsteich, Oberer before 1679 68,000 10.78
Middle Kellerhals Pond Kellerhalsteich, Mittlerer 1724 436,000 14.90
Lower Kellerhals Pond, Kellerhalsteich, Unterer before 1679 53,000 8.10
Kiefhölz Pond Kiefhölzer Teich before 1671 248,000 9.72
Klein-Clausthal Pond Klein-Clausthaler Teich around 1680 29,000 8.34
Little Crane Pond, Kranicher Teich, Kleiner before 1675 11,000 2.47
Great Crane Pond, Kranicher Teich, Großer before 1675 110,000 8.24
Kreuzbach Pond Kreuzbacher Teich before 1680 9,000 5.58
Kuttelbach Pond Kuttelbacher Teich 1674 163,000 12.75
Lange Pond Lange Teich 1719 15,000 6.73
Langer Pond Langer Teich before 1606 49,000 7.30
Upper Nassenwiese Pond Nassenwieser Teich, Oberer around 1671 132,000 8.82
Lower Nassenwiese Pond (†) Nassenwieser Teich, Unterer (†) before 1743 48,000 6.0
New Pond (Lautenthal)(†) Neue Teich (Lautenthal) (†) after 1680 11,800 5.8
Oder Pond Oderteich 1715-1721 1,670,000 18.00
Little Oker Pond Okerteich, Kleiner 22,000
Upper Peacock Pond Pfauenteich, Oberer before 1551 121.000 8.27
Middle Peacock Pond Pfauenteich, Mittlerer before 1551 259.000 9.53
Lower Peacock Pond Pfauenteich, Mittlerer before 1551 214,000 8.94
Pixhai Pond Pixhaier Teich 1672 281,000 8.75
Polster Valley Pond Polstertaler Teich 1728 46,000 6.48
Prince's Pond Prinzenteich 1686 385,000 8.74
Röhre Pond Röhrenteich
Lower Schalke Pond (Unterer) Schalker Teich 1730 151,000 11.28
Middle Schalke Pond (†) Schalker Teich, Mittlerer
Upper Schalke Pond (†) Schalker Teich, Oberer
Schlacke Valley Pond Schlackentaler Teich 3,200
Schröterbach Pond Schröterbacher Teich 1652 73,000 9.06
Schwarzenbach Pond Schwarzenbacher Teich before 1608 146,000 7.39
Semmelwiese Pond Semmelwieser Teich 1691 53.000 7.24
Silver Pond Silberteich 1755 22,000 8.0
Upper Spiegelthal Pond Spiegelthaler Teich, Oberer before 1673 51,000 7.67
Lower Spiegelthal Pond Spiegelthaler Teich, Unterer 1672 152,000 10.91
Stadtweg Pond Stadtweger Teich 1727 294,000 10.12
Stuffen Valley Pond (†) Stuffentaler Teich (†)
Marsh Pond (Buntenbock) Sumpfteich (Buntenbock) before 1639 189,000 6.91
Than Pond Than-Teich before 1684 12,000 6.45
Sandpiper Pond Wasserläufer Teich before 1659 25,000 5.78
Wiesenbeke Pond (Bad Lauterberg) Wiesenbeker Teich (Bad Lauterberg) 1715 480,000 14.50
Zankwiese Pond Zankwieser Teich 1688 107,000 9.67
Upper Mine Pond Zechenteich, Oberer before 1661 33,000 5.85
Middle Mine Pond Zechenteich, Mittlerer before 1661 45,000 6.70
Ziegenberg Pond Ziegenberger Teich around 1645 313,000 8.94

(†) means: pond out of service, largely dry. Dam remains exist.

Where no data is given, this usually indicates that the pond ended up in other hands before the mines closed and has not been precisely documented.

See also

Sources

External links

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