The Grane 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 ...
above the village of Astfeld/Herzog-Juliushütte in the borough of
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 ...
in the
Lower Saxon part of the
Harz
The Harz (), also called the Harz Mountains, is a 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 name ''Harz'' der ...
mountains.
Dam system
It is the newest
dam in the Harz, built in 1969 in the Grane valley. Because the river
Grane itself does not deliver enough water for the 3 km long
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 ...
, a 7.4 km long diversion channel was built from the
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 (Germany), Aller, in length and runs in a generally northerly direction.
Origin and meanin ...
river below the
Oker Dam. This also collects water from the
Gose on the way. A further 4.8 km long diversion runs from the
Radau to the Großer Romke and thus into the Oker-Grane Tunnel as well. Likewise there is a 4.6 km long tunnel to the
Innerste Dam. The operator of the Grane Dam, as well as its associated diversion systems and waterworks is the ''
Harzwasserwerke''.
The barrage is an
earth dam with asphaltic concrete lining.
Reservoir
The Grane
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 ...
(''Granestausee'') supplies
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 ...
, acts as
flood protection, water regulation and
electricity generation
Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delivery (Electric power transm ...
. The
hydro-electric power station has a power output of 180 kW. The waterworks for drinking water lies higher up on the northern slope. The water from the reservoir is pumped up into a compensating storage basin of 60,000 m³ capacity, from where it flows to the waterworks. The Grane Dam has an average annual discharge of 55 million m³.
Because the reservoir provides drinking water,
water sports
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known living organisms ...
are not allowed. Even motor traffic is kept away from it. A track for maintenance was laid around the reservoir, which is also open to walkers and cyclists and is about 17 km long.
There is a checkpoint (no. 110) in the
Harzer Wandernadel
The Harzer Wandernadel is a system of hiking awards in the Harz mountains in central Germany. Hikers (or mountain bikers) can earn awards at different levels of challenge by walking to the various checkpoints in the network and stamping their ...
hiking network by the reservoir known as ''Granestausee''.
See also
*
List of dams and reservoirs in Germany
*
List of dams and reservoirs in the Harz
Notes
*
External links
Harzwasserwerke.de with link to current dam data
{{Authority control
Dams in Lower Saxony
Dams in the Harz
Dams completed in 1969