The statistical base for the map of groundwater levels are collected by the team of the regional geology and regional groundwater service of the ministry for urban development (Senatsverwaltung für Stadtentwicklung) and by the Berlin water supply company (BWB) in watershed of their waterworks. Measurements of 1,446 groundwater measurement points only from the main groundwater aquifer (2. GWL), are processed in the present map. In the case of all daily measured groundwater measurement points the data from 31st of may 2001 was used, for the remaining ones the monthly value of May 2001.
