The groundwater condition is determined by natural and a large number of human influences. In the densely populated conurbation of Berlin, the following influences with natural and anthropogenic causes may affect the groundwater condition:
- Hydrogeological boundary conditions (flow; tension),
- Groundwater intake in the catchment areas of waterworks,
- Infiltration of surface water into the groundwater,
- Areas suspected of containing hazardous waste with proven groundwater contamination,
- Building rubble and debris disposal sites (rubble dumps etc.),
- Wastewater leakage from the inner-city sewerage system (exfiltration),
- Direct seepage of road run-off,
- Leaching fields located in the suburbs and the surrounding areas (some of them dating back to the past),
- Rain water percolation and retention ponds.
In order to implement the principle of precautionary groundwater protection, which is enshrined in the Water Resources Act and in the Berlin Water Act and to achieve sustainable groundwater management, measuring networks are operated in Berlin as part of information-oriented groundwater monitoring. Information provided by these measuring networks about the groundwater level and condition also is used to ensure the long-term supply of Berlin with high-quality water from wells situated in its urban area.
About 20 years have passed since the measuring programmes were installed in Berlin. A preliminary assessment and summary was made in the mid-80s (SenStadtUm 1986) and shown in the Environmental Atlas (SenStadtUm 1993). Following the standardization of the different measuring programmes, new assessments for all of Berlin are now available. In addition to the application of an adapted method for assessing the measured values, it became possible to translate the measuring results from specific places to the area as a whole.