The Kelbra
Reservoir lies on the river Helme behind the Kelbra Dam at the northwestern foot of the Kyffhäuser hills. It is located within the Goldene Aue, mainly in the district of
Mansfeld-Südharz (
Saxony-Anhalt); only a small area in its extreme southwestern sector, which is on the border of the
Kyffhäuserkreis and
Nordhausen districts, lies in Thuringia, which touches its southwestern
shore. Initially only a green - i.e. normally dry -
flood retention basin was planned. In the event, however, a full dam was built in order to create a permanent reservoir, and an auxiliary dam, in order to provide a basin that absorbed the bulk of the Helme river system in the event of high water. As a result, there are two adjacent basins, the lower one being permanently impounded – i.e. as a permanent lake – a gauge on the lake indicating a height of , a storage volume of 12.3 million m³ and a surface area of about 600 ha. The upper basin, which is bordered on its western and northwestern shores by
arable and
pasture land, is only impounded during times of high water. Together, both basins have a volume of 35.6 million m³, of which 23 million m³ is exclusive flood control capacity. Following the completion of the trial impounding of the Kelbra Reservoir, which lasted until 1969, it was officially taken into service. The lake is used extensively for
tourist purposes and has facilities for
sailing and
windsurfing, a beach for swimming, a
campsite,
boat and
bicycle hire, a
petting zoo a
waterslide and, near the lake, various
inns and other facilities. == Internationally important bird habitat ==