Oker Dam

Found constructor, Found decommissioned, Found developer, Found licence_expires,

The Oker Dam (German: Okertalsperre) is a dam in the Harz mountains in Lower Saxony, Germany. It is fed by the River Oker.

Technology

The dam is in the shape of an arch (see arch-gravity dam). It is 75 m high, 260 m long, can impound up to 47 million m³ of water and provides hydropower, flood protection and water regulation at times of low water. It is also used indirectly for the production of drinking water. Its average annual discharge is 75 million m³. The hydro-electric power station at Romkerhalle is fed by the Oker Reservoir.

Dam, downstream side

Dam, downstream side

Downstream face of the dam

Downstream face of the dam

Spillways on the dam

Spillways on the dam

Table with technical data on the Oker Dam

Table with technical data on the Oker Dam

History and location

The construction of the Oker Dam was begun by Hr. Press in the years 1938 to 1942 and then completed between 1949 and 1956. Its completion became pressing following the devastating floods in Wolfenbüttel and Brunswick in the winter of 1946/47 when there were heavy falls of snow. Before work started the small hamlet of Schulenberg in the valley had to be abandoned; it was rebuilt above the reservoir.

Dam

A dam is a barrier that impounds water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for such activities as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect water or for storage of water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions.

The word dam can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities.

History

Ancient dams

Early dam building took place in Mesopotamia and the Middle East. Dams were used to control the water level, for Mesopotamia's weather affected the Tigris and Euphrates rivers, and could be quite unpredictable.

The earliest known dam is the Jawa Dam in Jordan, 100 kilometres (62 mi) northeast of the capital Amman. This gravity dam featured an originally 9-metre-high (30 ft) and 1 m-wide (3.3 ft) stone wall, supported by a 50 m-wide (160 ft) earth rampart. The structure is dated to 3000 BC.

Damè

Damè is a town and arrondissement in the Atlantique Department of southern Benin. It is an administrative division under the jurisdiction of the commune of Toffo. According to the population census conducted by the Institut National de la Statistique Benin on February 15, 2002, the arrondissement had a total population of 11,034.

References

Coordinates: 6°51′00″N 2°05′00″E / 6.8500°N 2.0833°E / 6.8500; 2.0833

Damé

Damé is a town in eastern Ivory Coast. It is a sub-prefecture of Agnibilékrou Department in Indénié-Djuablin Region, Comoé District. Seven kilometres east of the town is a border crossing with Ghana.

Damé was a commune until March 2012, when it became one of 1126 communes nationwide that were abolished.

References

Oker

The Oker is a river in Lower Saxony, Germany, that has historically formed an important political boundary. It is a left tributary of the River Aller, 105 kilometres (65 mi) in length and runs in a generally northerly direction.

Origin and meaning of the name

The river's name was recorded around 830 as Obacra and, later, as Ovokare und Ovakara. The origin of the name is derived from the roots ov- and -akara meaning “upper” (cf. New High German ober-) and “onward rushing” (rendered in German as “Vorwärtsdrängende”) as distinct from its tributary, the Ecker, whose name means only “onward rushing”.

Course

The Oker rises at about 910 metres in the Harz National Park in a boggy area on the Bruchberg in the Harz mountains of central Germany. This early section is known as the Große Oker ("Great Oker") and it is impounded below Altenau by the Oker Dam (Okertalsperre). From the dam wall to the former village of Oker, which is today part of the borough of Goslar, the Oker is on certain occasions suitable for canoeing. This section, often called the "Oker Valley" (Okertal), includes the Romkerhall Waterfall. Here the Romke stream drops about 64 metres in height over a waterfall laid out in 1863 into the Oker. Downstream in the river's fast-flowing waters, the Verlobungsinsel ("Betrothal Island") is to be found. Left and right of the Oker in this area are many crags that are popular with climbers.

Oker (Goslar)

Oker has been part of the borough of Goslar in central Germany since 1972. It lies on the edge of the Harz mountains and has a population of 7,282 (as at 2006). Previously Oker had been a parish within Wolfenbüttel district since 1952.

Geography

Location

The village lies at the exit of the Oker valley between the Hahnenberg and Adenberg hills in the south and Sudmerberg in the north. Oker is divided into two unofficial districts: Oberoker ("Upper Oker"), south (and nearer the Harz) of the railway line, and Unteroker ("Lower Oker"), north of it.

The river Oker gives its name to the village.

History

Founded in 1527 as a smelting site for the processing of ore from the Rammelsberg mines, Oker was a centre of Harz smelting technology . In 1819 a branch of the Brunswick Postal Service was opened. This was moved to the railway station on the opening of the railway between Goslar and Vienenburg (on 23 March 1866).

Economy

Today Oker is home to chemical-metallurgical, recycling and specialised industrial concerns, like Harz-Metall and Norzinco. The largest employer in Oker and the district of Goslar is a factory belonging to H.C. Starck-Gruppe.