The Oderbruch (from Middle High German brouch meaning a marshy ground, swamp or moor; bruch is related to the English term brook) is a landscape at the Oder river in eastern Germany on the Polish border. It extends from the towns Oderberg and Bad Freienwalde in the north to Lebus in the south, in the county of Märkisch-Oderland in the state of Brandenburg. The Oderbruch is about 60 km long and its width varies from 12 to 20 km for a total area of some 920 km2. It is a slightly inclined plane descending from 14 m in the southeast to just one meter above sea level in the northwest.
The Prussian king Frederick the Great initiated the drainage of the Oderbruch in order to bring this large tract of marshland under cultivation. Since that time the land west of the river has been river polder, whereas the 17% of the Oderbruch which is now in Poland has retained its original wetland character.
The region experienced two months of heavy fighting which devastated the area at the close of World War II when Marshal Georgy Zhukov led the 1st Belorussian Front through the Oderbruch on the way to Berlin.
Until the 18th century the Oder meandered in several arms through this low-lying area, much of which flooded several times each year, a process which regularly altered the course and importance of the various channels. Fishing was the most important occupation for the inhabitants of the few Oderbruch towns that existed at the time. Today the Oder’s main channel is restrained to the eastern edge of the depression, and the remnants of the former branches bear designations like Alte Oder (“Old Oder”) or Stille Oder (“still” in the sense of motionless).
Today’s Oderbruch landscape was shaped by the regulation of the river in the 18th century. The construction of embankments and drainage work began in 1735 but was primarily carried out between 1747 and 1762 under the Prussian king Frederick II. As intended, in a short time a large part of the Oderbruch was drained and could be settled. Some 130,000 morgen (32,500 ha) of fertile farmland had been obtained. In Letschin a monument was erected to honor Frederick II in gratitude for his initiative to drain the Oderbruch.