The Aschergraben (ditch) is one of the technical masterstrokes from Altenberg’s early mining days that was essential to both mining and ore-processing. The man-made water ditch was constructed between 1452 and 1458 to provide a constant and reliable water supply to waterwheels and processing works (for power and ‘dressing’), a task it fulfilled for over 500 years. In the high-precipitation ridge areas of the Ore Mountains it was particularly important to gather, store and transport valuable water to the industrial locations where surface water was commonly in short supply, and also vulnerable year-round (from drought or freezing). From the 15th century, the installation of an elaborated system of ditches captured the abundant and renewable water sources of the upland moors where the soil type and vegetation acted as a ‘sponge’.
In 1464 Hans Münzer gained control of Lauenstein and sold the man-made ditch to the Altenberg tin works in the same year. Originally starting at the transboundary forests (the name of the ditch presumably came from the ‘ashers’ who burnt dry branches from the forests to manufacture potash), the Aschergraben flows from the high moorland of Totes Kind (Cínovecký hřbet), above Böhmisch-Zinnwald (Cínovec) to Altenberg and the Tiefenbach valley where it combined with the Tiefenbach stream to provide water and power for stamp mills and ore washers such as the Wäsche IV.
As a result of modern mining activities, the Aschergraben’s water today cuts off into the Georgenfelder Wasser (steam) weir, from where it runs into the historic Aschergraben. The new ore dressing and flotation works have been built over the end section, and the water up to the overflow structure now runs beneath the former residential accommodation of the VEB Zinnerz (socialyowned enterprise), before being diverted around the Tiefenbach heap, and joining up with the waters of the Tiefenbach stream. They then flow down towards Geising via a waterfall. The Aschergraben (water ditch) runs dry from the overflow structure onwards, but is still discernible. The course of the 7.4 km-long preserved section is functionally linked to the Wäsche IV. After the cessation of mining in 1991, the water from the ditch was no longer needed, though the ditch has been preserved as a functional waterway.