The Upper Harz Ditches (, ) are hillside

ditches A ditch is a small to moderate trench created to channel water. A ditch can be used for drainage, to drain water from low-lying areas, alongside roadways or fields, or to channel water from a more distant source for plant irrigation. Ditches a ...

, running roughly parallel to the

contour lines A contour line (also isoline, isopleth, isoquant or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensi ...

, that were laid out in the

Upper Harz The Upper Harz (, ) is the northwestern and higher part of the Harz mountain range in Germany. The exact boundaries of this geographical region may be defined differently depending on the context. In its traditional sense, the term Upper Harz cover ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

from the 16th to the 19th centuries to supply

water power Hydropower (from Ancient Greek -, "water"), also known as water power or water energy, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kin ...

to the

silver mines Silver mining is the extraction of silver by mining. Silver is a precious metal and holds high economic value. Because silver is often found in intimate combination with other metals, its extraction requires the use of complex technologies. In ...

there. They are an important component of the

Upper Harz Water Regale The Upper Harz Water Regale (, ) is a system of dams, reservoirs, ditches and other structures, much of which was built from the 16th to 19th centuries to divert and store the water that drove the water wheels of the mines in the Upper Harz region ...

, a historical water system that is now a

cultural monument A national heritage site is a heritage site having a value that has been registered by a governmental agency as being of national importance to the cultural heritage or history of that country. Usually such sites are listed in a heritage registe ...

Design

The ditches consist of a trench and an

embankment Embankment may refer to: Geology and geography * A levee, an artificial bank raised above the immediately surrounding land to redirect or prevent flooding by a river, lake or sea * Embankment (earthworks), a raised bank to carry a road, railway ...

(''Grabenbrust'') next to it, made of spoil piled up when the ditch was excavated. The embankments are frequently protected from

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

by a

dry stone wall Dry stone, sometimes called drystack or, in Scotland, drystane, is a building method by which structures are constructed from stones without any mortar to bind them together. A certain amount of binding is obtained through the use of carefully ...

. In most cases, they also act as inspection paths for the ditch keepers (''Grabenwärter'') and, today, as

public footpath A footpath (also pedestrian way, walking trail, nature trail) is a type of thoroughfare that is intended for use only by pedestrians and not other forms of traffic such as motorized vehicles, bicycles and horses. They can be found in a wide va ...

s. The ditches are only inclined at about 1–2 ‰ (i.e. about 1 to 2 millimetres per metre). As a result, they run almost parallel to the contour lines of the terrain. As protection against

seepage In soil mechanics, seepage is the movement of water through soil. If fluid pressures in a soil deposit are uniformly increasing with depth according to u = \rho_w g z_w, where z_w is the depth below the water table, then hydrostatic conditions wi ...

the embankment and bed of the ditch are usually sealed with grass sods or

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

. At inlets, where the ditch crosses forest streams, there are so-called ''Fehlschläge'', small

weirs A weir or low-head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the water level. Weirs are also used to control the flow of water for outlets of l ...

, by which the water flow in the ditch can be regulated. When water levels are high these have to be opened, i.e. the boards controlling the flow must be removed. The hydraulic capacity of most ditches is between 100 and 200 litres per second; on the Rehberg Ditch it is up to 600 L/s and on the Dyke Ditch up to 1000 L/s.

List of the Upper Harz ditches

The ditches are listed in an order which is based on the system by

Preussag TUI AG ( trading as TUI Group) is a German multinational leisure, travel and tourism company; it is the largest such company in the world. TUI is an acronym for ''Touristik Union International'' ("Tourism Union International"). TUI AG was known ...

, who named the ditches in an order based on the power stations that could be supplied by them. At present only those working ditches still operated by the ''

Harzwasserwerke The Harzwasserwerke GmbH (; English: Harz Water Works Limited) is a major German water company and dam operator based in Hildesheim, located within the German federal state of Lower Saxony. History Founded in 1928, the Harzwasserwerke were task ...

'' are shown.

Sources

* * * *

External links

Upper Harz Water Regale (German)
{{coord missing, Germany Aqueducts in Germany Kunstgraben

Design

List of the Upper Harz ditches

See also

Sources

External links