The Ecker Dam was the third modern reservoir built in the Harz mountains, after the construction of the Söse Dam in 1928–1931 and the Oder Dam in 1930–1933. It was laid out in the Ecker catchment area at the foot of the Brocken massif, characterised by extended upland bogs and heavy precipitation of up to a year. The reservoir uses a section of the river valley which, below a prominent trough end, was dug out in the shape of a basin by an ice age glacier.
