To cater for all the pumping in the Harz, (largely by water wheels both on the surface and underground) large volumes of water were required. This was collected over a very wide area by leats (i.e. watercourses or ditches) with 67 separate reservoirs, totalling 604 acres and storing 336 million cubic feet of water. In total there were about 125 miles of leats (known as "graben" in German) and these were sometimes engineered to flow though hill sides to reach their objective. Here is one such water tunnel (vasserlauf) complete with date stone on the important Damm Graben waterway. Following these leats is almost as fascinating as the mining remains themselves.
This photograph is by Dickie Bird and was uploaded December 15th 2014. © Dickie Bird please do not copy or distribute without prior express permission.