The Upper Harz Ditches (german: Oberharzer Gräben, ) are hillside

ditches A ditch is a small to moderate divot 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 ar ...

, running roughly parallel to the

contour lines A contour line (also isoline, isopleth, 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-dimensional graph ...

, that were laid out in the

Upper Harz The Upper Harz (german: Oberharz, ) refers to 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, th ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

from the 16th to the 19th centuries to supply

water power Hydropower (from el, ὕδωρ, "water"), also known as water power, 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 kinetic energy of a wa ...

to the

silver mines Silver mining is the extraction of silver from minerals, starting with mining. Because silver is often found in intimate combination with other metals, its extraction requires elaborate technologies. In 2008, ca.25,900 metric tons were consumed ...

there. They are an important component of the

Upper Harz Water Regale The Upper Harz Water Regale (german: Oberharzer Wasserregal, ) 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 ...

, 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 regist ...

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, railwa ...

(''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 water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

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. Dry stone structures are stable because of their construction m ...

. 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 ...

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 Soil mechanics is a branch of soil physics and applied mechanics that describes the behavior of soils. It differs from fluid mechanics and solid mechanics in the sense that soils consist of a heterogeneous mixture of fluids (usually air and wat ...

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

sods Sods is a term used in the Allegheny Mountains of eastern West Virginia for a mountain top meadow or bog, in an area that is otherwise generally forested. The term is similar (perhaps identical) to that of a " grass bald", a more widespread desi ...

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

. 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 river 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 Group is a German leisure, travel and tourism company. TUI is an acronym for ''Touristik Union International'' ("Tourism Union International"). TUI AG was known as Preussag AG until 1997 when the company changed its activities from mining to ...

, 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. Founded in 1928, the Harzwasserwerke were tasked with sup ...

'' 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