The dam is classified as a rockfill dam with a central asphalt concrete core and an upstream concrete face.
The reservoir has a maximum storage capacity of approximately 46.4 million cubic meters.
It is the newest of the major dams managed by the Harzwasserwerke in the Harz region.
The dam wall reaches a height of 62 meters above the valley floor.
The reservoir covers an area of roughly 190 hectares at full capacity.
Because it provides drinking water for large parts of Lower Saxony, strict hygiene regulations are enforced around the perimeter.
The Granetalsperre is a large dam and reservoir located in the Harz mountain range near Goslar, primary serving the purpose of drinking water supply for the region. Completed in 1969, the rockfill dam features a concrete upstream facing to ensure water impermeability. The reservoir impounds the Grane river and is part of a complex water management system in the Harz region. It is strictly protected as a drinking water reservoir, meaning no swimming, diving, or water sports are permitted. A paved path encircles the reservoir, spanning approximately 14 kilometers, which is popular for hiking and cycling. The structure is managed by the Harzwasserwerke, which regulates water levels for both supply and flood protection purposes.
The crest of the dam wall offers the best panoramic view of the reservoir and surrounding forest.
Bring a bicycle to complete the 14-kilometer perimeter loop in roughly an hour.
Pack binoculars, as the reservoir is a significant habitat for various bird species.
Carry sufficient water and snacks, as there are no commercial vendors directly on the reservoir path.
Do not attempt to access the water's edge or enter restricted maintenance zones near the dam wall.
No swimming, fishing, or camping; stay on marked paths to protect the water quality.
