Groundwater Levels 2001
The groundwater surface, that is strongly modified in Berlin since over hundred years by the drinking water supply, was -like in the last six years- in May 2001 on a relatively high level. Since 1989 a strong reduction of groundwater withdrawal can be observed. In 1989 the groundwater withdrawal amounts of the Berlin Water companies stood at 378.4 Mio. m3 (incl. Stolpe Waterworks). In the year 2000, 225.3 Mio. m3 of raw water was withdrawn, the withdrawal volume of the BWB sank 40 % (fig. 7). Reason for this is the retrograde water consumption, that is to be read in the reduced raw water withdrawal of the Berlin water businesses. Five smaller Berlin waterworks discontinued their production completely in the last years: Altglienicke 1991, Friedrichsfelde 1992, Köpenick and Riemeisterfenn 1995 and Buch 1997. The decline of production in the waterworks of the eastern districts between 1989 and 2000 was even still higher with 62 percent. The dramatic reduction in demands on groundwater especially in the neighbourhood of the recently de-commissioned waterworks, has resulted in a city-wide groundwater increase, especially so in the pleistocene watercourse region of southeast Berlin. Nearby these waterworks groundwater levels are rising up to 3 m.
In July 2001, in order to achieve groundwater states which allows settlement areas without water damages and as a reaction to the spatial unequal development of water demand inside Berlins, the Berlin senate made the following decisions:
In the long term, 50 percent more groundwater should be available for the public water supply in the eastern half of the city, to be taken from the regional network where consumption allows. The groundwater supply to southeast Berlin should be increased to a future 90 Mio. m3 per year from the present 60 Mio. m3 per year. After repair and rennovation, the Berlin water-pipe network should supply drinking water to the west of the city.
Through the additional groundwater withdrawal for drinking water production in the neighbourhood of the waterworks in southeast Berlin, the increase of the groundwater level can be stopped and consistent groundwater states for residential areas can be guaranteed.
As a consequence of the increased drinking waters production in southeast Berlin and in order to safeguard public drinking water supplies, the Berlin water companies must cut production in the western half of the city by 30 Mio. m3 per year. Thus increasing groundwater reserves in the proximity of the waterworks where production is reduced, but also spreading the problems of water-logging from east to west. In order to counteract this, the levels of groundwater concentration (through the infusion of purified surface water into the subsoil) should be controlled to reduce the problem and achieve an approximate levelling of groundwater states throughout the city.