Heavy precipitation triggered a landslide at the Müllera spring water intake. Due to the slipped surface layers, runoff surface water could quickly reach the Müllera spring water intake and impaired the drinking water quality. In addition, it could not be ruled out that the landslide surface extended further up the slope due to erosion. In order to prevent further extension of the slide surface and to ensure that the spring water intake was not affected by surface water runoff, the rock surface exposed by the slide was sealed with an approx. 0.2 m thick layer of clay, which was covered with bentonite mats. Drainage pipes were laid over the clay/bentonite mat cover to drain off surface water runoff in the immediate catchment area. With the rehabilitation measures implemented, the spring can continue to be used for drinking water.