Herzberger Teich, Reservoir near Goslar

Herzberger Teich, also called Herzer, is an artificial pond in the mountain valley between the Rammelsberg and Herzberg hills near Goslar. Its earthen dam is 11.80 m high and 140 m long, impounding about 94,000 m³ over 2.14 ha, with a maximum depth of roughly 5 m. A brick intake tower with an elliptical cross-section stands in the water.

Built in 1561 by the Goslar town council and Duke Heinrich the Younger of Brunswick-Wolfenbüttel, the pond stored water for the underground water wheels that drained the Rammelsberg mine. In 1768 mine official Johann Christoph Röder had the dam raised by 1.92 m, bringing capacity to nearly 100,000 m³. From 1805 its water ran into the Röder adit and powered four wheels until 1909.

The pond's name links it to the Herzberg hill between the Rammelsberg and the Wintertal. Its water powered the mine's underground wheels and, from 1805, four wheels in the Röder-Stollen before draining through the Rathstiefsten Stollen. Since 1988 the Harzwasserwerke have owned the dam, now part of the UNESCO World Heritage listing of the Rammelsberg mine and Upper Harz water system.

The reservoir lies in the narrow Bergtal valley between the Rammelsberg and Herzberg, at the mouth of the Wintertal, right beside the former Rammelsberg ore mine's surface buildings. The dam is 11.80 m high and 140 m long, with a water depth of about 5 m. The intake tower from 1907 stands on the dam, a brick shaft about 14 m tall with an elliptical cross-section.

The reservoir's 1907 intake tower is a brick structure about 14 m tall with an elliptical cross-section of 2.0 by 2.4 m; its walls thicken from 25 cm at the top to 77 cm at the base. In 1954 a DN 300 steel siphon was installed as the bottom outlet, largely putting the tower out of service. The outlet now discharges around 440 litres per second.