Wedeler Au

History and catchment area; in the red hamburger border

Wedeler mill pond and water meadows from the west; forward the Schulauer road

The Wedeler Au is a creek in Northern Germany 12.6 km in length, of which 6 km and 6.6 km to Hamburg Schleswig- holsteinischem area. This makes it the longest Springing in Hamburg Elbnebenfluss because the sources of the longer river Bille, Alster and Este are all situated in Schleswig -Holstein and Lower Saxony.

Your source is in Sülldorf, a district in the Altona district of Hamburg, directly at the border to Schenefeld and Iserbrook; west of the built-up urban area of ​​Wedel joins the Wedeler Au into the Elbe. The area is known as " eco-region 14 ( central plains) " classified. From the river their type is a sand- dominated lowland stream (type 14).

By 1960, the creek was one of the most polluted waters of the Federal Republic; The mid-1980s began taking measures for its restoration. In the 21st century Wedeler Au has been developed to Leitgewässer a natural regional park of around 5,130 ha, which is considered as a pilot project for transnational cooperation in the metropolitan region of Hamburg.

• 7.1 Printed sources
• 7.2 External links

Significance in the past

As Thoroughfare never played the Wedeler Au due to its brevity and its small size, but also because of their orientation elbparallelen a role, you can see from the sheltered estuary near Auhafen from. Probably since the Bronze Age led a ford that was part of the ox path between Jutland and the lower Elbe, through the lowlands along the lower reaches; close to this point is the origin of the town Wedel. In John Mejers " Landt Carte of the county Pinneberg " of 1650 is called the Au still Wedel Beck and has a striking contrast to the present-day course on: the time it arose far north-east of Schenefeld. It was not until much later, this section has been partly drained, partly drained into the northward flowing Düpenau.

At the dam of the mill pond, in the former field of Schulau Mark - now the eastern part of Wedel - a water mill was built in the 16th century. That Sülldorfer or Rissener farmers Wedeler Au used in the early modern period to bring corn to the local grain mill, would be conceivable, but is unoccupied. On the other hand, the fact that there are only a handful of rather pathetic peasant holdings were in these two villages, their fields far from the creek were ( approximately along the present-day B 431 ), while the intermediate, boggy lowlands ( called Low German as " Brook " ) was used only for grazing and for the recovery of Lohe from the bark of oak trees and reeds and cultivated until the 19th century. The less likely it would be the existence of a second mill in the area, as it has sometimes been derived from the old establishment situated on the banks of the Rissener Wedeler Au corridor designation " Woistmöhlen ". For cutting of the reeds (here " Katt'nküll " or " Bullnpesel " called ) attracted the men from the villages every year together in the wetland; dried, it was used as a straw and feeding.

Until about 1800 and the north up to the middle reaches of the Au -reaching zoom area was deforested. Only after the Holstein Land Reform of 1793 began here afforestation of moorland and heathland to the present forest Klövensteen. Until 1937 this river was completely holsteinischem territory; only through the Greater Hamburg Act were the city of Altona and thus the upper 6 km of the Wedeler Au part of the Land of Hamburg, one year later amalgamated into the city of Hamburg.

Today's course and escort trips

The width of the Wedel Au varies from 0.5 m at the top and 3 m in the lower reaches, where she also achieved a good 1 m its greatest depth; only the former Auhafen it has been artificially broadened considerably. At a medium slope of 0.02 ‰, it has only a low energy of flow. Its catchment area covers 55.85 km ², of which 21.64 km ² are (corresponding to 39 %) to Hamburg and 34.21 km ² on the Schleswig-Holstein region; east and north borders their catchment area to which the Düpenau, south and west of that of the Elbe.

The Wedeler Au rises to around 21 m above sea level. NN in the Sülldorfer field marks, a Geest area, and initially flows in a north- north- westerly direction along the city limits between Hamburg and Schenefeld, being cased after just a few meters is led to a retention basin, it serves as a receiving water in case of overflow due to heavy rainfall. Then it happened in 1981 decommissioned " WWTP West" on the road Ellernholt and describes open again by predominantly green and arable land with old tree rows and kink structures fluently, a slightly meandering half sheet in west southwest. After 3.5 km - east of Klövensteenwegs, where another retention basin is - it leaves the agricultural area and borders the forest of the south Klövensteen adjacent single and terraced housing of the district from cracks. After a short, sharp swing to the south (west of Gernot road ) it flows at the level of the site of Hanna- Reemtsma Foundation back in west south-westerly direction on where it leaves the Hamburg State area after 6 km, at Schulauer Moorweg.

From then on the Wedeler Au runs largely parallel to the S -Bahn route Altona- Wedel ( S1) through meadows until it north of Wedel station and city center expands to the mill pond which is dammed by a first time in 1314 in a document mentioned weir. Behind the weir it enters the Wedel Marsh, where lies on the crossing under the road Schulauer the former Auhafen; This is since the early 1970s, the theater ship Batavia. In addition, there exists a small boat harbor, the further use of the city, however, has prohibited the end of the 2000s. The last 2.1 km, the reedy, from here tidal river Au initially flows in a southwesterly direction in front of the old dike ( Brooks dam ) through the marshland. Since the extension of the Hamburg yacht harbor on the Elbe will shortly prior to their historic estuary to the north- west, where it again bends sharply to the south at the confluence with the Hetlinger Binnenelbe and drained by a storm surge secure locking mechanism in the new line of dykes in the Lower Elbe.

A continuous path along the creek bank does not exist. The source and wide sections of the upper reaches are, if anything, can be seen best from a distance or from the dirt road bridges. In the middle reaches then again a footpath runs from the mouth of the trench to Klövensteenweg a field and bridle path for a few hundred meters parallel to shore, but rarely with views of the water, to the west of the Südschwenk Rissener Gernot road. From Klövensteen forth the accessibility is better because the right bank slopes less steep there; the left side, it is up to 4 m high. On Wedeler area extends Autal to mill pond a long, paths, bicycle and hiking trail ( " Auweidenweg " ) right next to the railway embankment, which allows a good view of the broad valley, but from the stream relatively far away. The same is true for the least northern edge of the valley way. Only the west again Schulauer road and turn only partially exists on the last two kilometers to the mouth of another opportunity to walk along the Wedel Au or to cycle.

Inflows and crossings

Most inflows are anthropogenically formed to trenches, short watercourses. Still in the field of Mark Wedel Au flow on the left side to Iserbrook, Ellernholt, flatly and anti-tank ditch. Bach downward follow the right-hand tributaries running ( with sedge ) and Rissener Moorgraben and Rüdigerau, but also mainly from drainage ditches (sand Bargmoor - or Schnaakenmoorgraben ) is fed. Near the city limits lead, in turn, on the left bank, the Schulauer Moorgraben ( with Steen Barg and Rissener village ditch ) and shortly before her own mouth on the right side the Hetlinger Binnenelbe in the Wedeler Au.

Several bridges cross the brook, including six partially busy road bridges ( Ellernholt, Klövensteen and Sandmoorweg in Hamburg, Autal, mills, Schulauer or Austraße in Wedel ). There are also many smaller bridges for pedestrians or agricultural vehicles, five alone in the first four Bach kilometers ( lanes 65, 67, 68, 82 and 81). Among the oldest crossings included the curved bridge floor in Wedel, but it has been demolished in the early 1980s as part of the planned expansion of its Schulauer road and replaced by a new bridge in which a Fluttor is let.

Water status

Physico- chemical status

At the upper and middle reaches, especially in intensively farmed area in Hamburg area, as well as the tributaries since the 1950s numerous straightening and fixing measures were ( trapezoidal cross section, bank fixation with Bongossi timber ) carried out with significant hydrological consequences. This generally led to an increase in flow rate, which was only slightly restricted by the opposing effect of the bridge structures - rather, they regularly reached especially after heavy rainfall peaks, making it great for aquatic organisms to a " Ausräumungseffekt " came. Moreover, in a superposition of rainfall with mixed water overflow from the Hamburg Sielnetz at close to the source retention basins were temporarily registered significant nutrient and pollutant loads that affected the chemical status of the water body negatively. Although the basin has ( Capacity: 17,600 m³ ) over a fine screen for mechanical clarification of the effluent water, but solely from this source can be fed into the stream in the long-term average of 15,000 m³, the COD of 1.5 t for this amount of water per year correspond. Furthermore, there are cracks in three Regensielauslässe ( discharge points of storm water from busy roads and industrial areas with sewage separation) connected for about 300 ha paved area. Approximately 250,000 m³ of rainwater On average there per year discharged to surface waters; corresponding to a load of 11 tons organic carbon (TOC ) per year.

In the bottom of the adjacent fields and pastures larger iron ocher deposits occur which affect leaching in the colonization ability of the water body for animals and plants also considerable. Creek bed, sediments and waters are largely organic substrate to sand- dominated, gravelly or rocky sections with their higher cleaning effect, however, rare; the dominant in the Wedel Au suspended sediment clouds the water. His acid-binding capacity is around 2 mmol / l, pH 6.7 to 7.6; to chlorides are no data available. The load on the oxygen balance with degradable organic substances ( saprobic ) was, according to water quality report from 1999 in the middle. A study of aquatic sediments for heavy metals showed in 1993 that the upper reaches with lead ( 31-60 mg per kg dry matter) and cadmium ( 0.46 to 0.90 mg / kg DM ) was charged relatively low, on the middle reaches near the state border, however, four times so high ( 120-240 lead, cadmium 1.81 to 3.60 mg / kg DM ).

Apart from agriculture, have also increasingly intensive recreational use, particularly in Klövensteen, and partly directly approaching the end especially in cracks and fronds on the shore area development ( residential, commercial, transport routes ) to the loss of natural riparian corridors and the limitation of the ecological development potential of Wedeler Au contributed. Taken together, this meant that the water quality of Wedeler Au, only in sections ( " very dirty ") and III was to evaluate ( " critically loaded " ) yet in 2001 as II -III.

Biological State

Flora

Autochthonous plankton may develop in the small rivers scarcely. Research about the prevalence of Phytobenthos have not been made. In general, the aquatic flora is here " compared to other lowland streams der Geest very pronounced; flooding, particularly in aquatic plants are largely absent, "for which the iron ocher precipitates could be the cause. In 2003, only an inspection of individual floating ( duckweed, water lilies ) and rooted ( pondweed, water star ) were observed aquatic plants; A systematic survey to date does not exist but.

Near-natural riparian zones are only partially available on Hamburg area as a result of stream regulation and the sections to the shore zoom ancient human uses and often only narrow. However, they are restored in the course of restoration since the late 1980s and widened ( see below); 2003 mainly cornices and sedges, and bur reed were found. In Wedeler section between border and mill pond, these measures were completed in 1994; there again reeds have built up.

However, the part immediately adjacent to the stream vegetation cover ( meadows and pastures, coniferous, deciduous, mixed and swamp forest, bog, marsh and dunes) have a much greater botanical diversity.

Fauna

For the Hamburg part of the stream are detailed investigation results. After the collected between 1982 and 1986 kinds land a flashy low population density and low species diversity was observed in the Fischbiozönose; were also long-lived species under-represented - an indicator of the poor state of Wedeler Au. The incidence decreased substantially on eels and two stickleback species ( three - and nine-spined stickleback ); Sticklebacks often the only assets to colonize ponds in the cultural landscape. American dog fish ( Umbra pygmaea ) and moderlieschen, even more rarely, brown trout, crucian carp, roach, gudgeon, tench and chub were only sporadically detected.

Can now be found in the mouth area to the same time as smelt, flounder and sea trout before, there and further upstream perch, pike and eels as prey fish species and of the Fried fish carp and the most frequently occurring in the sphere of influence of the Elbe bream and ide.

The macrozoobenthos in 2000 /01 studied in upper and middle reaches. It outweighed annelids ( oligochaetes ) and small crustaceans ( amphipods, isopods ). Among the insects, caddis flies, Fly and here especially midge larvae are strongly represented. Near the source occurred in addition to other insects, such as bed bugs, mud, flies and beetles. The freshwater shrimp is the largest individual- type throughout the Hamburg section.

Many state birds that were native to the mid-20th century, no longer occur at the Wedel Au, such as grouse, curlew and nightjar, which lacks as a result of agricultural intensification and fertilization of butterflies, beetles and other flying insects. However, the area due to the diversity of adjacent vegetation types still offers numerous birds habitat. Highlighted Pungent are two areas: the open wet meadows of the upper and middle reaches, on which breed rare and specially protected species such as lapwing, kingfisher, marsh warbler, snipe and Whinchat and nest, and the estuary and North Sea near march with around 160 species of birds.

Restoration and protection areas

From the mid- 1980s, there was a cautious change of direction in dealing with the Wedel Au. This was in addition to an environmental consciousness changing, that the field of activity of the few established within the Sülldorf - field Rissener Mark farmers of intensive cultivation and toward services " around the horse " shifted; one of the remaining farmers engaged in organic farming nowadays. Even in local government understanding of the changing demands grew on the recreational value of semi-natural landscapes in the big city. In the 1990s, it was increasingly used in practice urban and regional planning; in Hamburg, for example, was not just a landscape, but in addition a species protection program developed in 1995 on the occasion of the creation of the new urban development concept. However, other land use interests compete (in this area primarily due to additional stables, attractive residential areas and road development ) continue with the restoration. In particular, the expansion of the original farms in the field mark is often difficult to prevent because of the " agricultural privilege " by the Building Code in practice. In the summer of 2010, the resident farmers complained of an increasing water logging of their land.

First of actions taken by the City of Wedel: from 1984, the mill pond was sludged and the entgradigt lying above stream. In Hamburg took over private conservation organizations ( NABU, GOEP ) "Bach sponsorships " and worked, supported by District Assembly and Altona District Office, in small steps from deficits. Some renatured stream sections meander back and were provided with a natural, gravel-covered insole and wood plantations flattened on the shore; two ponds with extensive marsh and shallow water zones were created and linked to the Wedeler Au. In addition, the reservoirs was built back in the middle reaches to a flood channel. In summer 2006, fingernail clams, gudgeon, stone loach, Berle and watercress were at the Au again encountered.

In 2007 are the Wedeler Au yourself and wide, especially to the north adjacent areas under protection. This is however neither a coherent under protection nor standardized instruments to enforce these protective regulations. Rather subspaces as a landscape protection area ( LSG ), Conservation Area (NSG ) or in national law passed on EU directives reported, and the responsibilities are distributed equally on different organs of the executive. Specifically, these are:

• In Hamburg of lying in the district of Altona stream section and its river banks as the "European fishing waters " under the EU Water Framework Directive, as Auenentwicklungsbereich after the landscape program and, except for a short distance east of the border, as part of the water conservation area Baur mountain
• Parts of the cracks - Sülldorfer field and forest of Klövensteen Mark as LSG
• The Schnaakenmoor as NSG, which was also registered as a protected area for the Fauna-Flora -Habitat Directive

• The entire stream section lying in Wedel as part of the Natura 2000 site " Schleswig- Holstein Elbästuar and surrounds "
• The stream section above the mill weir as part of LSG " Holmer sand mountains and moorland areas "
• The stream section below the mill weir as part of LSG " Wedel Marsh "
• The mouth region of the Wedel Au with its outer dike located floodplain rest as part of the NSG " Haseldorfer Binnenelbe with Elbvorland "

In addition, the entire stream and its spacious environment is designated under the EC Nitrates Directive as " endangered " and under the Urban Waste Water Directive as " sensitive area ".

Creation of a regional park

Since the beginning of the 21st century, the project of a transnational regional parks " Wedeler Au / cracks - Sülldorfer field mark " which extends to the north well above the catchment area of the stream, but urban population centers spares existed. From its planned 51.3 km ² area are 36% in Hamburg, 27 % in Wedel, 13% in Holm, 11 % in Pinneberg, 7% and 6% in Appen in Schenefeld. As the first project of its kind in the Hamburg metropolitan region it is a model for cooperation between the states of Schleswig -Holstein, Hamburg and Lower Saxony thereto but not involved. Recognition as a pilot project took place in 2003; in the fall of 2005, the contract for an ongoing peer review process at the Hamburg landscape architects Schaper, Steffen and Runtsch was assigned, set up a project related working group of representatives of the participating communities under the auspices of the Wedel city administration and this presented the first report version in May 2007. The report contained a stock assessment, presented use conflicts, gaps and potential for development is and included a target and framework as well as a detailed set of proposals for concrete actions. According to the schedule, from 2008 to 2013 to realize a portion of the individual projects and to present as a regional contribution to the International Garden Show 2013 in Hamburg- William Castle.

In summary, the focus of the concept lay on a " backup scenic sensitive zones " and their " development ... to increase the local recreation attractiveness ", to be produced by a network of paths composite with viewpoints and supplemented by " focus areas for intensive recreation ." " The eponymous Wedeler Au is as Leitgewässer to develop " with the receipt of the extensively used grassland and the " natural water structures " is of key importance.

Of the 20 proposed individual projects in four sub-areas relating directly to the Wedeler Au and its vicinity: An upper and middle reaches was, inter alia, the proposed " extensification and partial rewetting of lowland grassland as a measure for meadow birds "; Also the source should be moved north of the road Ellernholt in a newly created, small marsh area. In the valley area on Wedeler territory to the mill pond, the expansion of recreational functions " which take account of a protected area of European importance " is - meaning the Natura 2000 site - followed, in the city center are " accessibility and perceptibility " be improved. In the mouth region eventually will also be promoted the "development of landscape-related, extensive recreation ". The town of Wedel was the first measure of the gap closure of the banks of the Elbe cycling and hiking trail in the area of the power plant - not in creek nearby - started, for which the Council has already approved funds for a total amount of about € 80,000. 2013 began an investigation into the extent to which since the reforestation overgrown by the forest inland dunes to an extent can be uncovered again, that they may serve as " stepping stones " for a large spatial dry biotope axis and the living conditions typical of the region plants and animals - for example, silver grass, heather, mountain sand bells, sand lizard and smooth snake - can help improve.

How the project in the coming decade Template: can be / In 5 years actually implemented future is partially still questionable. On the one hand there is a majority of the required land in private ownership; on the other hand has the contradiction between the intended improvement of the traffic accessibility and intensification of recreational use and the concept of maintaining and expanding natural areas yet to be solved even after the experts' opinion. In the spring of 2008, the concept was to be her first public, but, although it is so intended not already done in 2010. A new club (Regional Park Wedeler Au eV ) was officially founded as a carrier of the Regional Park - Instead, in November 2009 - after about one and a half years of statutes discussion in the participating municipalities and the district of Pinneberg.

2013, there are two projects in the implementation phase. Firstly, it has several GPS - supported " digital information paths " through the park. On the other hand have to Wedeler territory the works for the construction of a " water adventure zone " started, which, however, still must precede soil sampling because it is a suspected contaminated area. There, individual access to the stream to be created. Information boards will be erected on each observed plants and animals for both projects.