Upper Harz Water Tunnels

The Upper Harz Water Tunnels (German: Oberharzer Wasserläufe, pronounced [ˌoːbɐhaːɐ̯tsɐ ˈvasɐlɔʏfə]) are part of the Upper Harz Water Regale - a network of reservoirs, ditches, tunnels and other structures in the Harz mountains of central Germany. The German term Wasserlauf refers to the underground element (i.e. the tunnels) of the network of watercourses used in the historic silver mining industry of the Upper Harz. This network of ditches and tunnels was used to supply the mines with headrace waters for their water wheels from the 16th century onwards. In the system of the Upper Harz Water Regale there are over 35 such tunnels with a total length of about 30 km (19 mi).

Exit portal of the Lower Hasenbach Tunnel

Construction

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Slag brick walls in the Franz August Tunnel

Although explosives were already in use in the 17th century in the mines of the Upper Harz, tunnels continued to be hewn out by hand, that is with hammer and chisel for much longer. The reason was that there were difficulties in determining the right amount of gunpowder and fears that tunnels running just under the surface would collapse or that the explosive would produce fissures in the rock causing water to leak away. Almost all water tunnels were driven by counter-heading. Until the 18th century the miners excavated tunnels by following the weakest rock; this sometimes created a zigzag route that deviated significantly from the direct line. Not until the 19th century were tunnels driven in a strictly direct line using explosives.

The incline necessary to create a flow of water often amounted to less than 1% (in other words less than 1 metre (3 ft 3 in) drop for every 1,000 metres (3,300 ft) of length). The profile of the older tunnels, that had been driven with hammer and chisel, was sometimes as small as 1.20 m (3 ft 11 in) high and 0.80 m (2 ft 7 in) wide. The newer tunnels, however, were generally 2 m (6 ft 7 in) high and 1 m (3 ft 3 in) wide.

Compared with ditches, tunnels had the important advantage that the water flowing through them underground could not freeze up. The tunnels were laid primarily to short cut the long ditch runs around mountains. Such cuts also produced a steeper incline (shorter distances descending the same height difference have a steeper slope). This raised the flow velocity and hence the hydraulic capacity of the watercourse. The disadvantage of tunnels was the high investment cost of building them.

List of working Upper Harz water tunnels

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The working tunnels shown in this table follow the order in the latest listing by Preussag, which is based on their use in the various power stations.

English Name German Name Built Length Route
Kellwasser Tunnel I Kellwasser Wasserlauf I 1821 170 m Dyke Ditch (Blochschleife) to the Nabe valley
Kellwasser Tunnel II Kellwasser Wasserlauf II 1821 229 m Blochschleife to Wiege on the Dyke Ditch
Rothenberg Tunnel Rothenberger Wasserlauf 1868 775 m Dyke Ditch: crosses the Rothenberg
Coventhai Tunnel Coventhaier Wasserlauf 1852 540 m Dyke Ditch: crosses the Coventhai
Dietrichsberg Tunnel Dietrichsberger Wasserlauf 1863 1,044 m Dyke Ditch from Fortune Pond to the "Fenster"
Bielenwiese Tunnel Bielenwieser Wasserlauf 1864 357 m Dyke Ditch from "Fenster" to "Teilung" (Mönchstal)
Mönchstal Tunnel Mönchstaler Wasserlauf 1677 474 m Dyke Ditch from Mönchstal into the Upper Hausherzberg Pond
Franz August Tunnel Franz Auguster Wasserlauf 1832 632 m Dyke Ditch from the Teilung into the Lower Peacock Pond
Jägersbleek Tunnel Jägersbleeker Wasserlauf 1771 132 m Träncke Ditch to the Jägersbleek Pond
Huttal Tunnel Huttaler Wasserlauf 1763 783 m Hirschler Pond to the Huttaler Widerwaage
Fortune Tunnel Fortuner Wasserlauf 1785 777 m Jägersbleek Ditch into the Middle Peacock Pond
Prince Wallis Tunnel Prinz-Walliser Wasserlauf about 1740 563 m Nassenwiese Ditch into the Johann Friedrich Tunnel
Johann Friedrich Tunnel Johann-Friedricher Wasserlauf 1673 805 m From the Johann Friedrich Pond to the Dorothea Water Wheel Ditch
Kellerhals Tunnel Kellerhalser Wasserlauf 1842 501 m From the Middle Kellerhals Pond to the New Kellerhals Ditch, later used in the course of the Zellerfeld Ditch
Winterwiese Tunnel Winterwieser Wasserlauf before 1690 488 m From the Zellerfeld Ditch into the Jungfrau Ditch / Middle Zechen Pond
Bremerhöhe Tunnel Bremerhöher Wasserlauf 1704 732 m Bremerhöhe Ditch to the Rosenhof Mining Area
Bärenbruch Tunnel Bärenbrucher Wasserlauf 1949 940 m From the Bärenbruch Pond into the "Upper Rosenhof Chute"
Upper Schwarzenbach Tunnel Oberer Schwarzenbacher Wasserlauf 1808 760 m "Upper Rosenhof Chute" to the Hasenbacher Widerwaage
Upper Hasenbach Tunnel Oberer Hasenbacher Wasserlauf 1811 638 m "Upper Rosenhof Chute" to Hasenbacher Widerwaage
Upper Flambach Tunnel Oberer Flambacher Wasserlauf 1763 780 m "Upper Rosenhof Chute" from Flambach to the Johannis valley
Upper Johannistal Tunnel Oberer Johannistaler Wasserlauf 1839 1,014 m "Upper Rosenhof Chute" Johannistal to the Klein Clausthal
Upper Klein Clausthal Tunnel Oberer Klein-Clausthaler Wasserlauf 1776 492 m "Upper Rosenhof Chute" from Klein Clausthal to the Rosenhof Mines
Ziegenberg Tunnel Ziegenberger Wasserlauf 1847 413 m "Lower Rosenhof Chute" from Ziegenberg Pond to the Schwarzenbach
Lower Schwarzenbach Tunnel Unterer Schwarzenbacher Wasserlauf 1870 524 m "Lower Rosenhof Chute" from the Schwarzenbach to the Hasenbach
Lower Hasenbach Tunnel Unterer Hasenbacher Wasserlauf 1845 959 m "Lower Rosenhof Chute" from the Hasenbach to the Flambach
Lower Flambach Tunnel Unterer Flambacher Wasserlauf 1844 973 m "Lower Rosenhof Chute" from the Flambach to the Johannistal
Lower Johannistal Tunnel I Unterer Johannistaler Wasserlauf I 1835 558 m "Lower Rosenhof Chute" from the Johannistal to the Klein Clausthal
Lower Johannistal Tunnel II Unterer Johannistaler Wasserlauf II 1835 234 m "Lower Rosenhof Chute"(continuation of Johannistal Tunnel I)
Lower Klein Clausthal Tunnel Unterer Klein-Clausthaler Wasserlauf 1792 791 m "Lower Rosenhof Chute" from the Kl. Clausthal to the Rosenhof Mines
Dorothea Rösche Dorotheer Rösche before 1771 325 m Drainage for the water wheel (Radstube Kehrrad) at Dorothea Pit
Gesehe Tunnel Geseher Wasserlauf 1698 722 m Rehberg Ditch to the Gesehr / St. Andreasberg
Schulte Adit Schulte Stollen 1838 1,220 m From the Innerste river to the Wiemannsbucht (Bad Grund)
Upper Eichelberg Tunnel Oberer Eichelberger Wasserlauf 1889 1,110 m From Wiemannsbucht to Schönhofsblick
Lower Eichelberg Tunnel Unterer Eichelberger Wasserlauf 1855 230 m Drain from the Knesebeck Shaft

List of disused Upper Harz water tunnels

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"Disused" refers to all those tunnels that are no longer in service. Some of these are completely preserved; others, however, have largely fallen into ruin. The following list makes no claim to being complete.

English Name German Name Built Length Route
Old Dietrichsberg Tunnel Alter Dietrichsberger Wasserlauf 1662 260 m Dyke Ditch: Bypasses the Dietrichsberg; became superfluous on the construction of the New Dietrichsberg Tunnel in 1863.
Old Upper Klein Clausthal Tunnel Alter Oberer Klein-Clausthaler Wasserlauf 120 m Upper Rosenhof Chute: Bypasses the Hüttenkopf
Old Lower Klein Clausthal Tunnel Alter Unterer Klein-Clausthaler Wasserlauf 200 m Lower Rosenhof Chute: Bypasses the Hüttenkopf
Benedict Tunnel Benedikter Wasserlauf 100 m Upper Kehrzug Ditch into the Hirschler Pond
Kalte Küche Tunnel Kalte Küche Wasserlauf 1821 410 m Dyke Ditch: crosses the Rothenberg; tunnel closed on the construction of the Rothenberg Tunnel in 1868.
Crane Tunnel Kranicher Wasserlauf 1878 600 m from the bottom outlet of the Crane Pond (Hahnenklee) to the Lower Raft Pond (Bockswiese)
Langer Tunnel Langer Wasserlauf before 1815 150 m Short channel from the Oker region to the Langer Pond
Nassenwiese Tunnel Nassenwieser Wasserlauf 250 m from the Nassenwiese Ditch to the Johann Friedrich Tunnel
Piss Valley Tunnel Pisstaler Wasserlauf 1732 1,100 m Stadtweg Ditch (from the Stadtweg Pond) to Bockswiese
Polsterberg Tunnel Polsterberger Wasserlauf 1767 1,23 km Originally a gallery in the Eisenstein mine; between 1767 and 1813 tunnel from the Polsterberg Pumpworks (Polsterberger Hubhaus) to the Huttal Pond
Schwarzenberg Tunnel Schwarzenberger Wasserlauf 1813 730 m Links the outlet area of the Söse with the Oker river
Tannhai Tunnel Tannhaier Wasserlauf 1875 430 m Links the Kellerhals Pond, Kellerhals Tunnel to Bockswiese, Wäsche Ditch

See also

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Sources

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The Huttaler Widerwaage and the portal of the Huttal Tunnel
  • Knissel, Walter; Fleisch, Gerhard (2004), Kulturdenkmal "Oberharzer Wasserregal" – eine epochale Leistung (in German), Clausthal-Zellerfeld: Papierflieger, ISBN 3-89720-725-7
  • Schmidt, Martin (2002), Die Wasserwirtschaft des Oberharzer Bergbaus, Schriftenreihe der Frontinus-Gesellschaft (in German) (3rd ed.), Hildesheim: Harzwasserwerke, ISBN 3-00-009609-4
  • Schmidt, Martin (2005), Das Kulturdenkmal Oberharzer Wasserregal (PDF) (in German), Clausthal-Zellerfeld: Harzwasserwerke
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