Statistical data for preparation of groundwater contour (watertable isohypse) maps were gathered from the Landesgrundwasserdienst (Berlin Groundwater Service) of the Berlin Department of Urban Development and Environmental Protection.
Regular recording of groundwater levels started in 1869, when 29 measuring points were established. In 1937 there were over 2,000 measuring points in Greater Berlin. In 1992 in West Berlin there were 1,581 observation wells. In East Berlin there were 2,380. The statistical basis for the map published here was selected from them.
There were considerable problems in preparing this first all-Berlin map. The East Berlin Oberflußmeisterei measuring network had many gaps and only 40% of them were even capable of functioning, according to studies conducted up to now. The hydrogeologic situation of individual measuring points is often either unknown, or else filters were set too shallowly in “floating tables”. Information regarding groundwater developments can be given only with reservations, generally speaking, because the hydrogeological situations at most of the existing East Berlin measuring points remain relatively unclear, especially outside the Pleistocene watercourse. The East Berlin groundwater measuring network is being renovated with all urgency and available means. The renovation began in January 1992.
In the current transitional situation, Berlin groundwater can be measured at only 2,000 groundwater observation wells (daily, every 14 days or monthly).
In addition to the statistical basis given by the groundwater measuring network, water table levels near lakes and running waters were included as supplementary measuring values when a hydraulic connection with groundwater is probable. An average value for all observation periods was assumed because of the low range of variation. The structural situations of all wells of the Berlin Public Water Companies were also given consideration, for they are the largest continual groundwater consumers.
The state environmental agency made data available for approximately 50 groundwater measuring points bordering Berlin in the state of Brandenburg. The well galleries of the Stolpe, Erkner, and Eichwalde waterworks were included because of their probable influence on groundwater conditions in Berlin.