The Innerste Dam () is a

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...

on the

Innerste The Innerste () is a river in Lower Saxony, Germany. It is a right tributary of the Leine river and in length. Origin of the name The river name is not related to the German word ''innerste'' meaning innermost. ''Innerste'', in earlier time ...

river, which lies near

Langelsheim Langelsheim () is a town in the Goslar (district), district of Goslar in Lower Saxony, Germany. Geography The municipality is situated between the river Innerste and its tributary the river Grane (river), Grane, on the northern edge of the Harz ...

and Wolfshagen in the

Harz mountains The Harz (), also called the Harz Mountains, is a Mittelgebirge, highland area in northern Germany. It has the highest elevations for that region, and its rugged terrain extends across parts of Lower Saxony, Saxony-Anhalt, and Thuringia. The nam ...

. It was built between 1963 and 1966 and belongs to the '' Harzwasserwerke''. Its purposes are the supply of

drinking water Drinking water or potable water is water that is safe for ingestion, either when drunk directly in liquid form or consumed indirectly through food preparation. It is often (but not always) supplied through taps, in which case it is also calle ...

flood protection Flood management or flood control are methods used to reduce or prevent the detrimental effects of flood waters. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and ru ...

, water flow regulation and

hydroelectric power Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

generation. The average annual discharge through the Innerste Dam is 60 million m³.

Structures

The Innerste is an earth-fill dam with multiple, external, asphaltic concrete layers. It has an inspection gangway along its whole length on the upstream apron. In front of the upstream base of the dam is a shaft spillway (a flood overflow tower), into which also the bottom outlet is integrated. The water of the Innerste Dam can be pumped via a 4.6 km long diversion channel to the

Grane Dam The Grane Dam () is a dam above the village of Astfeld/Herzog-Juliushütte in the borough of Langelsheim in the Lower Saxon part of the Harz mountains. Dam system It is the newest dam in the Harz, built in 1969 in the Grane valley. Because ...

further east, where it can be used for

water treatment Water treatment is any process that improves the quality of water to make it appropriate for a specific end-use. The end use may be drinking, industrial water supply, irrigation, river flow maintenance, water recreation or many other uses, ...

. From 2003 to 2005 the reservoir was completely emptied and renovated, especially the asphalt sealing and the bottom outlet. This work was finished in September 2005.

Flood control

Because the reservoir only has a limited flood control capacity (i.e. its capacity is relatively small in relation to the annual discharge), it can only check flooding within certain limits. The flood relief facility (

spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

) is used about every two years. Nevertheless, even when the Innerste Dam overflows, the level of retention significantly reduces and delays flooding.

Recreation

The

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

may be used by sailing and rowing boats and for angling and camping. The Innerste Valley Railway is an old railway line, that had a halt by the Innerste Dam.

Gallery

File:Innerstetalsperre_UEberlauf.jpg, Shaft spillway in the reservoir File:Ueberlaufturm-18.10.03.jpg, Shaft spillway during renovation work File:Innerstestausee_Niedrigwasser.jpg, Reservoir at low level File:Innerste_im_Stausee.jpg, Innerste at low water File:Innerstetalsperre Panorama.jpg, View of the Innerste Dam

Sources

External links