The designation 'Raschpëtzer' in the Helmsange forest refers to a series of shafts along a line at more or less regular invervals. Excavations have revealed an underground conduit and water collection system using Persian 'qanat' techniques. The bases of the shafts are linked by means of a gallery which incorporates a channel for the water.
The dimensions of the system are impressive; a length of 600 metres with a depth of 36 metres at the lowest point. It is still functioning today, supplying 180 m3 of drinking water per day.
Water is collected from under the Haedchen depression where the sub stratum is sandstone. Water percolates through the walls along the length of the eastern section of the gallery where it ends. The canal starts at the interface between the sandstone and the underlying impermeable stratum and it descends at a shallow gradient towards the western side of the hill.
Download here a 21 page brochure summarising the extent of the current information about the 'Raschpëtzer'.