Groundwater Levels of the Main Aquifer and Panke Valley Aquifer 2017
The present groundwater contour map describes the groundwater situation of the Main Aquifer with violet groundwater isolines and the Panke Valley Aquifer in north-eastern Berlin with blue isolines. The interval between the groundwater isolines is 0.5 m. These show the potentiometric surface area of the unconfined and confined groundwater, respectively (see also Fig. 3). In areas of the Main Aquifer with confined groundwater, the groundwater contours are displayed in broken lines. In areas with no main groundwater aquifer, or with an isolated main groundwater aquifer of low thickness, no groundwater isolines are displayed. Those areas are shown with black dots.
The map is based on the topographical General Map of Berlin, scale of 1 : 50,000, in grid format, and the geological outline for the Berlin state territory, at a scale of 1 : 50,000, which was derived from the geological General Map of Berlin and Surrounding Areas, scale of 1 : 100,000. In addition, the appropriate support points (groundwater measurement points and surface-water levels) as well as the individual waterworks are indicated, with their active wells and water conservation areas.
On the plateaus, the main aquifer is extensively covered by the glacial till and bolder clay (aquitards) of the ground moraines. Wherever the potentiometric surface of the main aquifer lies within such an aquitard, groundwater conditions are confined. In sandy segments above the till or in islands, near-surface groundwater may be formed, which is also called stratum water (see also Fig. 3). After extreme precipitation, it may rise to the surface. The groundwater levels of these locally highly differentiated areas have not been separately ascertained and portrayed.
In the Panke Valley, on the northern side of the spillway, the Barnim Plateau, a major independent coherent aquifer has developed. It is located above the main aquifer, which is covered by the glacial till of the ground moraine (see also Figs. 7 & 8). On the present map, this aquifer is indicated by separate blue groundwater isolines. A spur of the glacial till toward the Warsaw-Berlin Glacial Spillway creates an interlock of the Panke Valley Aquifer with the Main Aquifer there.
For more information, see the Groundwater Brochure:
www.berlin.de/sen/uvk/_assets/umwelt/wasser-und-geologie/publikationen-und-merkblaetter/grundwasser-broschuere.pdf (only in German)
Current Situation in May 2017
As a rule, the groundwater incline in Berlin, and hence, too, the flow direction, is from the Barnim and Teltow Plateaus and the Nauen Plate toward the receiving bodies, the Spree and Havel Rivers. Depression cones have formed around the wells at those waterworks in operation during the measurement period, and have sunk the phreatic surface below the level of the neighbouring surface waters. Thus, in addition to inflowing groundwater from the shore side, the water pumped here also includes groundwater formed by infiltration (bank-filtered water) from these surface waters (see also Fig. 4c).
In May 2017, too, the potentiometric surface, which has been lowered in Berlin by drinking-water discharge over the past hundred years, was at a relatively high level compared to 1989 (Limberg et al. 2007: pp. 76 ff.). Areas in the Glacial Spillway in which the groundwater rebounded over this period of time by more than half a meter and by more than one meter, respectively, are shown on the difference map 1989-2012 (Fig. 10).
The reduced raw-water discharge by the Berlin Water Utility since 1989 as a result of the decreased need for drinking and industrial water is responsible for the constant rise of the groundwater level. Moreover, five of the smaller Berlin waterworks (Altglienicke, Friedrichsfelde, Köpenick, Riemeisterfenn and Buch) were shut down altogether in the period from 1991 to 1997. In addition, drinking water production at the two waterworks Johannisthal and Jungfernheide has been discontinued temporarily since September 2001; at the latter, the same has been true for artificial groundwater recharging. However, under the immediate water management measures of the former Senate Department for Urban Development and the Environment, groundwater is still being discharged at the Johannisthal location in order to support current local waste disposal and construction measures. Likewise at the Jungfernheide location, groundwater was discharged by the Department through the end of 2005. Since January 2006, a private company has performed the groundwater management there for continuing the dewatering of the cellars.
The Water Conservation Districts of the Buch, Jungfernheide and Altglienicke waterworks were abolished in April 2009.
The overall discharge of raw water by the Berlin Water Utility for public water supply dropped by almost half (42 %) in Berlin over a period of 28 years. In 1989, 378 million cu.m. were discharged, as opposed to 219 million cu.m. in 2002. In 2003, the discharge briefly increased slightly to 226 million cu.m. due to the extremely dry summer. After a further phase of decline, the discharge increased again to 221million cu.m. in the past years (Fig. 11).
The development of the groundwater levels from May 2016 through May 2017 is exemplified at four measurement points which are largely unaffected by the withdrawal of water by the waterworks (Fig. 12).
The groundwater levels at the two measurement points in the unconfined aquifer of the Glacial Spillway exhibit nearly the natural annual variation with low groundwater levels in autumn and high ones in spring. The amplitude of the hydrographic curve of the groundwater level of Measurement Point 340, which is situated on the outskirts of the city, is pronounced, while that of the inner-city Measurement Point 5139 exhibits an attenuated annual variation. The short-term fluctuations in groundwater levels here in December and January are rather connected to construction projects involving both lowering of the level as well as adding to the level. Due to a very “dry” year, the groundwater level at Measurement Point 340 was more than one decimetre lower on 15 May 2017 than in the year before (Fig. 13 and 15).
By contrast, on the Teltow Plateau and on the Barnim Plateau, the development of the groundwater level at Measurement Points 777 and 5004 in the covered, confined aquifer was similar to the one in the Glacial Spillway during the same period (Fig. 14). However, here the annual variation with the natural fluctuations is not as pronounced as at Measurement Point 340. Due to a very “dry” year, the groundwater levels at both measuring points were more than one decimetre lower on 15 May 2017 than in the year before (Figs. 14 and 15).
In the period from June 2016 to May 2017, the precipitation amount at the Berlin-Tempelhof Measurement Point, with 183 mm, was significantly below that of the long-term mean (1981-2010). Only three of these months displayed a monthly mean respectively that was slightly higher than the long-term monthly mean (Fig. 15). As a result, groundwater levels were up to one decimetre lower in May 2017, than in May 2016 (Figs. 13 and 14).
Information on the expected highest groundwater level (EHGL), which is an important basis for planning the design of buildings, can be found in the Environmental Atlas under: /umweltatlas/en/water/groundwater-level-ehgl/2018/maps/artikel.962088.en.php (Limberg et al. 2015).