Aller - Aller Glacial Valley

Aller Glacial Valley

After the Aller had passed through the hills of Saxony-Anhalt, it entered the Wolfsburg area into the ice age drainage channel of the Aller glacial valley, part of the Breslau-Magdeburg-Bremen glacial valley. The valley, which on average is 20 km wide, was formed during the penultimate ice age, the Saale glaciation about 200,000 years ago and drained meltwaters from the ice sheet into the North Sea. The present course of the Aller in the miles-wide glacial valley does not reflect the courses of numerous streams of earlier centuries and millennia. For a long time there was a system of interwoven water courses, that changed their location and size depending on the materials and quantities of water being carried. Today there is a large number of dry oxbow lakes, river beds and branches in the water meadows. Climatic conditions and the work of erosion also changed the landscape around the streams of the glacial valley. For example, the wind formed inland sand dunes parallel to the river, especially on the northern side of the valley, around which the river sometimes snaked in meanders.

Near Wolfsburg the level of the river bed scarcely dropped at all and during times of low water it became almost an area of standing water. The Wolfsburg Volkswagen Factory uses the river and also feeds waste water, after cleaning, into its own sewage works.

Today the landscape of the Aller valley between Celle and Verden is mainly utilised as grassland. The Aller depression there comprises valley floors lying close to the watertable, so that fertile wet areas may be found here with rich habitats for flora and fauna. The landscape is characterised by ox bows, potholes, copses and rows of bushes. The valley floors are widened by the depressions of the tributaries flowing into to the Aller, so that fens and bogs can form. Around the lower reaches crops are cultivated on the clay soils. Around the upper course of the river, many pine forests are managed on the sandy soils.