Stable embankments and lack of water

“The slopes of the Schöningen open-pit mine were left exposed for a long time. Without vegetation, rain has an easy time of it, and erosion channels form”, says Michael Rüger. But erosion isn’t the only threat to the stability of the slopes. With the planned flooding of the open-pit mine pit and the associated rise in the groundwater level in the area surrounding the mine, the structural conditions of the mine’s slope systems are also changing. Their stability must be ensured on a permanent basis to rule out any future risk of landslides.

The GINGER HPC team and the solutions

Michael Rüger generally tackles such multifaceted challenges with a diverse and interdisciplinary team. For the Schöningen open-pit mine, geologist Stefanie Liebetrau, hydrogeologist Matthias Kater, geotechnical engineer Andreas Janel, and engineer Uwe Thomas are on the job. They secure the pit, collect soil and rock samples, and model the groundwater recharge rate while factoring in climate change. Regarding the future lake at the Schöningen open-pit mine, hydrogeologist Kater says: “The flooding process will take a long time. But the new lake will have a pleasant pH level – unlike in Lusatia, where the lakes often become acidic due to pyrite weathering in the tailings piles.”

To stabilize the open-pit mine slopes, the GINGER HPC team relies on a combination of different solutions: “First, we adapt the geometry of the slopes to the extreme conditions on site, which means we ensure gentle gradients,” says Michael Rüger. “In addition, we reinforce the pit edges and install hydraulic structures in the eroded areas,” adds Uwe Thomas. The eventful history that the GINGER HPC team encounters in its work is not limited to East and West. The spears and bones that archaeologists unearthed in the open-pit mine are a full 300,000 years old. It was likely Homo heidelbergensis who used the wooden hunting weapon found in 2016. For a long time, the embankment built for the GDR border security facilities remained visible even as water levels rose. Soon, it will be flooded. The resulting lake has been named Lappwaldsee. It will cover ground steeped in history.

The Schöningen open-pit mine is a special place: here, the past and the future are laid bare as if under a magnifying glass—from the Paleolithic era through the inner-German border to GINGER HPC’s solutions for post-mining landscapes.