Pretziener Wehr

The Pretzien weir near the village of Pretzien is part of a dike system to protect the cities of Magdeburg and Schönebeck from flooding of the Elbe. After the weir has been opened, up to a quarter of the Elbe's outflow will be diverted via the Elbe Flood Canal via Biederitz east of Magdeburg and Schönebeck.
The Elbe runs at the level of the Pretzien weir in a six to eight kilometre wide glacial valley, in which the course of the river would constantly change without human intervention, forming meanders. Before the 10th century, the Elbe ran along the eastern edge of the glacial valley along a ridge from Dornburg to Hohenwarthe. In the following centuries, the Elbe shifted westwards towards Schönebeck and Magdeburg. An intermediate course of the river from Ranies via Grünewalde and Randau to Salbke has been preserved as the Old Elbe.

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