Little all

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Little all
Course of the Kleine Aller west of the Vorsfelder Werder, map from the 18th century

Course of the Kleine Aller west of the Vorsfelder Werder , map from the 18th century

Data
Water code DE : 48134
location Germany ( Lower Saxony )
River system Weser
Drain over Aller  → Weser  → North Sea
source northwest of Brome , district Wiswedel
52 ° 37 ′ 13 ″  N , 10 ° 51 ′ 42 ″  E
Source height 78  m above sea level NHN
muzzle south of Weyhausen in the Allerkanal Coordinates: 52 ° 27 '3 "  N , 10 ° 43' 49"  E 52 ° 27 '3 "  N , 10 ° 43' 49"  E
Mouth height 55  m above sea level NHN
Height difference 23 m
Bottom slope 1 ‰
length 22.8 km
Catchment area 143.08 km²
Left tributaries Rhodian Aller
Big cities Wolfsburg
Communities Wiswedel, Voitze , Tülau-Fahrenhorst , Bergfeld , Barwedel , Tiddische , Wolfsburg- Brackstedt , Tappenbeck , Wolfsburg- Warmenau , Weyhausen
The Kleine Aller is listed in the upper reaches under GKZ 48138 and as water body 14022, in the lower reaches the water body no. 14019.
Kleine Aller at the crossing under the B 188 near Wolfsburg -Warmenau
Mill wheel of the Brackstedter mill on the Kleine Aller

The Kleine Aller is an approximately 23 km long and up to five meters wide tributary of the Aller or Allerkanals in Lower Saxony . It flows from north to south and runs through the Gifhorn district and the city of Wolfsburg .

course

The Small Aller rises in Bromer district Wiswedel to 78 meters above sea level . It drains the Kiebitzmoor west of Tülau and the Vogelmoor north of Barwedel through a ditch system that has been continuously expanded over the last centuries . In this area it also receives an inflow from the Rhodian Aller . The Kleine Aller then flows south and passes Bergfeld , Barwedel, Tiddische , Hoitlingen and Jembke . From the height of Jembke it forms the border between the district of Gifhorn and the city of Wolfsburg. The river also passes Wolfsburg- Brackstedt and Wolfsburg- Warmenau , to flow south of Weyhausen into the Aller at 55.5 m above sea level, before the Allerkanal branches off a few hundred meters.

Origin and history

The course of the river, like the surrounding landforms, was created in the penultimate ice age , the Saale Ice Age . The ice masses formed the area over 100,000 years ago with their ground moraines . The river formed as a drain of the higher Geest in the Aller- glacial valley .

In the Middle Ages , the valley of the Kleine Aller represented a natural border between two regions running in a north-south direction. These were the area of ​​the Boldecker Land in the west and the historical landscape of the Vorsfelder Werder in the east. From the 15th to the 20th century, the water drove the Brackstedter mill near Brackstedt .

In the course of its formation, the Kleine Aller was able to develop a valley around 10 m deep with a valley width of around 1,000 m in its middle course, in which a low moor has formed. In the past, the lowlands could only be used as grassland due to frequent flooding, but today mainly arable farming is practiced in the floodplain . The originally meandering Kleine Aller was straightened and canalized over almost its entire length in 1865. For this purpose, the river bed was re-dug. By converting the river to prevent flooding, the land in the lower valley of the Kleine Aller could be used as arable land.

Renaturation took place in sections near Tülau, Bergfeld and Tiddische, where a new course was created in parts. The naturally designed areas were planted with alder trees. This also provides shade, as the river is largely exposed to the sun. This leads to weeds, which causes the river bed to become silted up. In 2018, the renaturation measures in the Tappenbeck and Warmenau area continued.

Water quality

A quality measuring station has been located near Warmenau since 1967, where the water quality has been regularly examined since 1976. The Lower Saxony water quality report from 2004 assesses the chemical water pollution of the Kleine Aller differently. The values ​​for organic pollution, nitrate , ammonium and phosphate pollution were between slightly polluted and very heavily polluted. The ammonium load in particular shows strong fluctuations and sometimes high values. This is attributed to the fact that the water is used as receiving waters for five pond sewage treatment plants and that the nitrogen content in these plants is not sufficiently reduced.

For the implementation of the European Water Framework Directive , the upper and lower reaches of the Kleine Aller are managed as two bodies of water by the NLWKN : The approximately ten kilometer long upper course with the GKZ 48138 under the number 14022 is the type of sand- shaped lowland stream , the approximately twelve kilometer long lower course under the number 14019 assigned to the type of sand and loam-shaped lowland river . As of November 2012, data sheets were created for both water bodies, in which the status and measures to improve the water quality are presented. The ecological potential of the upper course is rated as “moderate”, which corresponds to grade 3, while the lower course is rated as “bad”, i.e. grade 5. For both river sections, considerable structural deficits such as straightening, bank reinforcement and lack of planting are listed and in addition to structural improvements Measures to increase the efficiency of wastewater treatment are also recommended.

Individual evidence

  1. ↑ a b State Office for Geoinformation and Land Surveying Lower Saxony: Top 50 - Topographic Map 1: 50,000 Lower Saxony / Bremen , as of 2000.
  2. ↑ a b NLWKN : Inventory of the implementation of the EU Water Framework Directive, processing area Aller / Quelle , Braunschweig November 2004, Appendix Table 3 listing of water bodies.
  3. ↑ Water quality report Kleine Aller of the NLWKN
  4. ↑ NLWKN operating point south: water body data sheet 14022 Kleine Aller , November 2012.
  5. ↑ NLWKN operating point south: water body data sheet 14019 Kleine Aller , November 2012.

Web links

Commons : Kleine Aller  - collection of pictures, videos and audio files