Kleine Aller

History of the Little Aller west of Vorsfelder Werder, map of the 18th century

The Small Aller is an approximately 15 km long and up to 5 m wide tributary of the Aller and the Allerkanals in Lower Saxony. It flows from north to south and passes through the Gifhorn district and the city of Wolfsburg.

Course

The Small Aller rises in Bromer district Wiswedel to 78 m above sea level. They drained through a in the last few centuries more and more developed system, the grave Kiebitzmoor west of Tülau and bird marsh north of Barwedel. In this area, it also receives inflow from the Rhodian all. Then the little Aller flows south, passing Bergfeld, Barwedel, Tiddische, Hoitlingen and Jembke. From the height of Jembke it forms the boundary between the District of Gifhorn and the city of Wolfsburg. The river passes further Wolfsburg and Wolfsburg Brackstedt - Warmenau to south of Weyhausen in the Allerkanal to lead at 55.5 m above sea level, the few hundred meters previously branching from the Aller.

Renaturation took place in sections at Tülau, Bergfeld and Tiddische, where here and there, a new course was created. The case naturally designed areas planted with alders. This also provides a shadow protection, because the river is mostly exposed to the sun. This leads to Verkrautungen, causing siltation of the river bed.

Origin and history

The river was as the surrounding landforms in the penultimate ice age, the Saale ice age. The ice formed the area more than 100,000 years ago with their moraines. The river formed as a drain of the higher Geest in the all- glacial valley.

The valley of the Little All set in the Middle Ages a natural, running in a north-south direction boundary between two tracts of land were Represents the area of ​​the Boldecker country in the west and the historic landscape of the Vorsfelder Werder in the east.

The Small Aller has in its middle course to develop a valley of about 10 m depth at a valley width of about 1000 m during its creation, in which fen has trained. Previously, the lowland was only to be used as grassland because of frequent floods, now mainly arable farming is operated in the floodplain. The original meandering Small Aller in 1865 to almost the entire length straightened and channelized. To this end, the river bed was newly dug. Through the conversion of the river with lack of flooding the land could be used in Niederungstal the Little Aller as farmland.

Water quality

In Warmenau is since 1967 a quality measurement point where the water quality is tested regularly since 1976. The Lower Saxony Water Quality Report 2004 assesses the chemical water pollution of Small Aller different. The values ​​were organic load, nitrate, ammonium and phosphate load between lightly loaded to heavily polluted. In particular, the ammonium load shows strong fluctuations and sometimes high values ​​. This is attributed to the fact that the five waters of waste water treatment plants pond serves as receiving water and that the nitrogen content in these plants is not reduced sufficiently.