Upper Harz Water Regale, Historic water management system in Harz Mountains, Germany

The Upper Harz Water Regale is a system of ponds, ditches and underground channels built from the 16th to the 19th century in the Harz Mountains. Its earth dams, straight embankments and narrow causeways link dark ponds and long channels across the slopes. The largest pond in the lower right is bordered by a straight embankment, while a smaller curving arm extends toward the upper left.

The Upper Harz Water Regale was built mainly between the 16th and 19th centuries to supply water to the mines of the Upper Harz, whose silver output accounted for 40–50% of German production from the 16th to the mid-19th century. Miners dug new ponds and ditches during periods when lack of water halted ore extraction. In 1978 the structures were placed under monument protection, and on 31 July 2010 they became part of the UNESCO World Heritage site Mines of Rammelsberg, Historic Town of Goslar and Upper Harz Water Management.

The channels and ponds shape the landscape today and show how generations controlled water here to support their work. Throughout the area, you can see the artificial waterways and understand how closely people and nature were connected in this region.

The system covers about 200 square kilometres, with most structures near Clausthal-Zellerfeld, Hahnenklee, Sankt Andreasberg, Buntenbock, Wildemann, Lautenthal, Schulenberg, Altenau and Torfhaus. The Harz Waterworks maintains 65 reservoirs, 70 kilometres of ditches and 20 kilometres of waterways, many with adjacent paths. The terrain is hilly and forested, so wear sturdy footwear.

The system's ponds were kept small because 16th- to 19th-century dam technology could not build earth dams higher than about 15 metres. Miners therefore created cascades of four to six ponds, storing water at the highest possible level so it could drive several overshot water wheels in succession.