The Bullengraben is a ditch in Berlin's glacial valley, which has been in use since the 7th century. It is located in the Berlin district of Spandau and runs from the old village center of Staaken eastwards for about five kilometers to the Havel River, into which it flows north of the Spandau castle rampart. Used for centuries to improve the wetlands, since the 1960s it has been used as a drainage ditch to collect rainwater from the surrounding neighborhoods of Spandau.
Between 2004 and 2007, DB ProjektBau reactivated a ditch that had been canalized in the 1960s and 1970s but had later been neglected. This reactivation was conducted as part of a replacement measure. Parallel to the moat, the Deutsche Bahn subsidiary created the 200-meter-wide green corridor with playgrounds and sports fields, recreational areas, bridges, footbridges, and a path that leads to Elsflether Weg. The Bullengrabenweg, one of Berlin's top 20 green paths, is open to pedestrians, cyclists, and skaters. The path is approximately four meters wide and has a smooth asphalt covering. The last section of the path includes the Burgwallgraben and a 100-metre-long promenade along the Havel. Additionally, biotopes located within the green corridor, such as the Stieglake and Wiesen basins, along with the ditches leading to them, such as the Egelpfuhlgraben, have undergone restoration. In 2008, Deutsche Bahn received the Gustav Meyer Prize for designing the park. This award is given every two years since 1995 to recognize excellent planning of public green spaces and parks.
Overview The Bullengraben stretches between Heerstraße and the Brunsbütteler Dam. It starts in the northwest of the Altstaaken village church at the old Staaken-West hospital, although it is hardly noticeable and has become overgrown for the first few meters of its length. The Bullengraben Green Corridor, a recently established site, is located approximately one hundred meters towards the east at Nennhauser Dam. A metallic bridge provides access to the lowland which leads to a small settling basin that is considered a symbol of the source of the Bullengraben. The ditch and green corridor later stretch towards the eastern direction, spreading over approximately 4.5 kilometers. In Staaken, it passes the Staakener fields and the Louise-Schroeder estate. The green corridor departs from Staaken at the intersection of the Egelpfuhlgraben and Neustaakener Graben. It serves as the boundary between the Spandau (to the north) and Wilhelmstadt (to the south) districts up to the Havel, where the district border follows both sides of the ditch. The ditch eventually leads to Elsflether Weg, passing through Klosterfeld, new housing developments, and allotment gardens in the Spandau district, before reaching the old housing developments around Klosterstrasse. A total of 17 bridges cross the Bullengraben, including several smaller wooden or metal footbridges connecting allotments and neighboring settlements.
Beyond the Elsflether Weg, the ditch and green corridor continue east for about 50 meters before ending at the back of the large Klosterstrasse development. At this point, the ditch subsequently runs underground towards the Havel. To the east of Klosterstrasse, the pipes are located beneath the Grünanlage am Ziegelhof, which proceeds straight to the Havel. The green corridor is interrupted but resumes to the southeast at Ziegelhof Street, following the Burgwallgraben which begins at this point and reaches the Havel River after about 300 meters in a semicircular path.
Geology and location
The Bullengraben lowland was formed from a previous flow channel located within the Weichsel glacial valley of Berlin. Currently, the Bullengraben flows in a direction against the original flow of the valley, from west to east, into the Havel channel. This channel, which crosses part of the glacial valley, finally discharges into the Havel about 800 meters south of the Spree. The valley is made up of substantial sand deposits that exceed 20 meters in depth. After the end of the Ice Age, soil rich in peat and limestone meadow deposits developed to the west of the Havel channel due to alluvial sedimentation processes. In contrast, the Spree flows through and drains the eastern part of the glacial valley in its natural direction of flow, whereas the western part of the Havel lacks significant rivers. The large lowland area was previously very wet and frequently flooded but was eventually drained into the Havel through ditches like the Bullengraben and the Spekte. These ditches flowed parallel to the Bullengraben, approximately one kilometer to the north. The northern slope of the Nauen Plateau, which borders the glacial valley here to the south, lies on average around one kilometer away from the Bullengraben.Elke Hickisch, Reinhard Hanke: Untersuchungen zur …, pp. 26.Schutz-, Pflege- und Entwicklungskonzept: Wiese am Bullengraben. …, pp. 1.
History of the Bullengraben and its settlement
Early melioration ditch and etymology The Bullengraben, which was most likely artificially created in a glacial flow channel, has been used since the Slavic settlement of Havelland in the 7th century, to effectively improve the wet lowlands west of Havel. This resulted in the possibility of pasture and hay farming. The name of the channel is believed to have originated from the Slavic term for hay bales. Another account suggests that the name arose from the channel's use as a watering trough for bulls. It is said that the Bullengraben and the Spekte were connected to the Elbe through a nearly uninterrupted canal network that extended to Nauen and the Havelland Luch.Elke Hickisch, Reinhard Hanke: Untersuchungen zur …, pp. 26, 28. However, Winfried Schich has cast doubt on these claims, stating that there is no evidence to support them:
Former estuary at the Slavic settlement
Up until the mid-19th century, the Bullengraben flowed into the northern section of the Burgwallgraben, which curved around the Burgwall Island in a semicircle. However, due to the construction of the Berlin-Hamburg railway, this part of the Burgwallgraben was filled in around 1870. There is no longer any connection between the Bullengraben and the southern remains of the Burgwallgraben.Elke Hickisch, Reinhard Hanke: Untersuchungen zur …, pp. 32. The Burgwall Island, which was one of the biggest archaeological excavation sites in Berlin/Brandenburg at the end of the 20th century, served as the focal point of the Slavic settlement chamber of Spandau. Apart from this central castle, there was an additional Old Slavic settlement on the Bullengraben between the 8th and 10th centuries, which is now known as Cosmarweg.Eberhard Bohm: Spandau in slawischer Zeit. In: Slawenburg, Landesfestung, Industriezentrum. Untersuchungen … pp. 24 f, 39, 53.Max Muth: Vorbericht über die Versuchsgrabung auf dem Burgwall in Spandau. In: Berliner Blätter für Vor- und Frühgeschichte, 10, 1963, Heft 1, Berlin 1963, pp. 6.
Klosterfeld and Ziegelhof The village of Stakene (Staaken), first mentioned in a document in 1273, was established at the source of the Bullengraben as part of the German settlement in the east. In the first half of the 13th century, the Ascanian margraves founded the Benedictine convent of St. Marien, and extensive farmyard in the estuary area. Until the dissolution of the convent in 1590, the Benedictine nuns cultivated their arable gardens on the land located in front of the convent gate between the Bullengraben, Burgwallgraben, and Havel. They possessed 60 hectares of arable land, which was 11.5 hectares more than the town of Spandau's field area.Felix Escher: Frömmigkeit und kulturelles Leben in Spandau vor der Reformation. In: Slawenburg, Landesfestung, Industriezentrum. Untersuchungen …, pp. 145–147. The Krummen Gärten ("Crooked Gardens"), situated directly on the Bullengraben, were also part of their possession. These gardens have been recorded on old maps. Nine small houses were laid out at Krummen Gärten in the 15th century, likely becoming the first residential buildings in the area outside of Staaken, the monastery, and Spandau city walls.Elke Hickisch, Reinhard Hanke: Untersuchungen zur …, pp. 2, 20 Around 1580, Rochus zu Lynar, the master builder of the citadel, obtained the nuns' farmland and began growing wine on the site.
After demolishing the old brick kiln on Stresow, Elector Georg Wilhelm commissioned the construction of a new council brickwork on the former monastery grounds in Spandau. The new brickworks included a kiln, a brick barn, and four lime barns, which were completed in 1676. Outflanked by the emerging brick-making centers of Glindow and Werder, the town demolished the brick kiln in 1755 and replaced it with a fruit tree plantation. The area experienced frequent flooding from the nearby Havel and Bullengraben rivers, leading the tenants to adopt an agricultural and gardening lifestyle. The area was part of the Klosterfeld and the Potsdamer Vorstadt, which formed the 8th district of Spandau from 1872. The development of the areas around the former Ziegelhof began in 1867 with the creation of Wilhelmstadt.Elke Hickisch, Reinhard Hanke: Untersuchungen zur …, pp. 8, 21, 24.
1811 Flooding Act and piping
To maintain clear and free-flowing ditches, Prussia implemented a law before the floods in 1811. The legislation required residents to clear the ditches every spring and autumn. The law was emphasized in public announcements:Zitiert nach: Elke Hickisch, Reinhard Hanke: Untersuchungen zur …, pp. 32.
Despite preventive measures, extensive flooding occurred around 1870, stretching from the Havel across Klosterstraße (then known as Potsdamer Chaussee) to the Egelpfuhlwiesen. The primary cause for this was the inadequate water supply in the Burgwallgraben, which had been filled in during railway construction. Consequently, the northern section of the Burgwallgraben was filled and the Bullengraben was diverted into the Havel.Elke Hickisch, Reinhard Hanke: Untersuchungen zur …, pp. 32f.
Canalization and change of function in the 20th century
The development of the meadows around the ditch started at the beginning of the 20th century. After the construction of the Staaken airfield in 1915, the ditch lost its function as a floodplain for the Staaken fields. Until the 1960s, the area around the ditch remained largely undisturbed in its development and use as meadowland. The Bullengraben lowland was permanently altered by large-scale embankments for the development of the Klosterfeld meadows and adjacent areas. In the 1960s and 1970s, the ditch was converted and expanded into a drainage ditch and canalized to collect the rainwater running off the surface. Three retention basins were created: Stieglake, Wiesen, and Ulriken. Due to the construction of large housing estates and the increased pumping of drinking water from the Spandau waterworks, the groundwater level of the Bullengraben lowlands dropped, causing the vegetation of the lowlands to change considerably.Schutz-, Pflege- und Entwicklungskonzept: Wiese am Bullengraben. …, pp. 1 f.Elke Hickisch, Reinhard Hanke: Untersuchungen zur …, pp. 38 f, 43.
In the Staakener fields, the Bullengraben flowed parallel to the inner-German border of Staaken, which was divided between 1951 and 1990, on West Berlin territory. The ditch was entirely overgrown and its lower regions were neglected during the 1980s and 1990s. After the reunification of Germany, additional urban neighborhoods were linked to the Bullengraben drainage network.
Hydrology and ecology before rehabilitation and renaturation All data on hydrology and ecology refer to studies conducted prior to the restoration and renaturation of the green corridor, which was completed in 2007. Information on the effects of the measures on the water balance and biotope quality as well as specific data on the "ecological improvement" carried out (see below) are not available.