In 2007 the administration of the medieval town Staufen, located in Baden-Wuerttemberg in the
south-western part of Germany, initiated the installation of geothermal power sensors for the
ecologically beneficial heating and cooling of the town hall. Seven holes were drilled into the ground,
each of a depth of 140m.

In the end of 2007 cracks appeared in the walls of houses within the historic core of the city. Due to
geological investigations it appeared that the drilling had perforated a bed of anhydrite and gypsum
with a thickness of about 30m, which was now beeing infiltrated by ground water, coming up from the
Middle-Trias layers beneath the anhydrite/gypsum bed. Since then the water provokes the swellable
rock of the anhydrit/gypsum bed to expand and thereby to elevate the medieval core of the town.
Until the end of September 2009 the elevation added up to 11mm per month, causing cracks,
fractures and clefts in the stonework of several buildings. A desaster.

In 2009 as countermeasures the geothermal power sensors where sealed and wells where installed,
from where since then the ascending groundwater is pumped off continuously. In result it is
stated that the elevation of the ground is slowing down, but it appears to be uncertain wether it
will come to a complete stop of the elevation in near future.

The picture shows a gypsum seal bridging a fracture in a housewall in order to determine further deformation.