Ollenbäke

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Ollenbäke
Data
location Ammerland district , Lower Saxony , Germany
River system Ems
Drain over Große Süderbäke  → Aper Tief  → Jümme  → Leda  → Ems  → North Sea
source Near Langebrugge, Bad Zwischenahn municipality
53 ° 13 ′ 50 ″  N , 7 ° 59 ′ 50 ″  E
Source height 8  m
muzzle Great Süderbäke near Apen Coordinates: 53 ° 12 ′ 48 ″  N , 7 ° 49 ′ 1 ″  E 53 ° 12 ′ 48 ″  N , 7 ° 49 ′ 1 ″  E
Mouth height 1  m
Height difference 7 m

Communities Bad Zwischenahn, Westerstede , Apen

The Ollenbäke is a 15-kilometer-long river in the Ammerland district in Lower Saxony .

It has its origin near the county road 346 near Langebrugge in the municipality of Bad Zwischenahn . From here it runs in a south-westerly direction. Between Bad Zwischenahn and Westerstede -Ocholt it changes its course in a north-westerly direction and flows south of Apen into the Große Süderbäke, which a little later at the confluence with the Große Norderbäke forms the Aper Tief . The Ollenbäke is to slightly above the municipal boundary between Apen and Westerstede tide affected. The tidal range is up to half a meter.

The entire course of the Ollenbäke has been largely straightened and since the mid-1950s it has been dyed for the last 750 meters above the confluence with the Große Süderbäke . It flows through an intensively used agricultural area, only occasionally through small forest areas. At Ocholt-Howiek, an old arm , the Alte Ollenbäke, branches off from the Ollenbäke. The Howiek watermill is located on it , which was built in 1608 with the permission of Count Anton Günther . The mill, which could only be used in winter, since only then was there enough water, was shut down in 1909, as the neighboring meadows suffered from the damming up of the water .

The deciduous forest around the old arm of the Ollenbäke with its richly structured forest edge and the Howieker watermill on the old arm was designated as a protected landscape component on March 6, 2004 . The area is approximately 4.41  hectares .

Containment measure

In 1997 and 1998, the Leda-Jümme-Verband and the Ammerländer Wasseracht relocated the dike on the right bank of the Ollenbäke in the area of ​​the confluence with the Große Süderbäke to the edge of the lowland on the Oldenburg – Leer railway line, thus bringing the Ollenbäke back with it connected to their floodplain , which in this area was characterized by agriculturally used wetland and wet grassland. At the same time, the old, meandering watercourse was restored in this area . The additional soil required for the construction of the new dike was taken from the floodplain area. This created shallow water zones that are connected to the Ollenbäke. The straightened course of the Ollenbäke was separated from the restored river course in the south and left as an oxbow.

In the area of ​​the approximately 18 hectare dike area, the Ollenbäke is subject to its natural flowing water dynamics again. It can overflow its banks and change its water bed , so that valuable habitats such as freshwater mud flats, floodplain bushes and reeds can arise. In some places sliding and impact slopes are formed .

The area also serves as flood protection . Flooding can spread over the retention area and slowly drain away again. The area should be able to hold around 150,000 m³ of water as a retention area . Measurements after the redesign of the site have shown, however, that up to 230,000 m³ of water can actually be stored. The re-dike measure was a model for a comparable measure at Aper Tief in 2005.

Flora and fauna

The area of ​​the dike area is subject to frequent water level fluctuations. Freshwater floodplains without vegetation form as well as areas with reeds, water plumes , cattails , pond rushes and floodplain . Furthermore, Großseggenrieder can settle. Perennial swamps, gray willow bushes and alder swamps develop on areas that have not been flooded .

The abandonment of the use and redesign of the area have created new habitats for various animal and plant species. So many come here now bird species that are used by many breed here or the area as food or resting habitat use, including as multiple Wat - and waterfowl . The dike is also a habitat for numerous dragonflies and ground beetles , and the same applies to butterflies and grasshoppers .

literature

Web links

Individual evidence

  1. ↑ The story of the Howiek watermill , Ocholt-Howiek local history association. Retrieved May 6, 2019.
  2. ↑ watermill Howiek , Lower Saxon Mill Road. Retrieved June 28, 2012.
  3. ↑ Ordinance on the protected landscape component “Howieker Watermill and Surroundings” (PDF; 111 kB) , Ammerland district, December 17, 2003. Accessed on June 28, 2012.
  4. ↑ a b Dike development and renaturation Ollenbäke , Ammerland district. Retrieved April 18, 2016.
  5. ↑ a b c Efficiency control of a compensatory measure at Ollenbäke (PDF; 2.3 MB) , Carl von Ossietzky University of Oldenburg. Retrieved June 28, 2012.
  6. ^ Kerstin Schumann: Aper Tief fascinates visitors , Nordwest-Zeitung , March 27, 2007. Accessed on June 28, 2012.