|This overlay shows the destroyed dam a view hours after the bombing. The hole caused by the especially manufactured bouncing-bomb can be seen and on the left you can see the flooded area down the river Eder. (The bouncing bomb was a kind of bomb designed by Barnes Wallis of Vickers-Armstrong. It was used in the famous Dambusters raid to attack major dams in Germany during World War II.)|
The Edersee is a large reservoir created by the construction, from 1908 to 1914, of a dam across the Eder river, near the small town of Waldeck in Northern Hessen, Germany, to generate hydropower and regulate water levels for shipping on the Weser river.
The dam was destroyed by special bouncing bombs dropped by British Avro Lancaster bombers during the night of May 16/17, 1943, creating massive destruction and loss of life downstream (Operation Chastise/Dambuster), including the drowning death of 749 Ukrainian POWs in a labor camp just below the dam. Through the breach in the dam, 70 meters wide and 22 meters deep, some 8,000 m≥ of water per second emptied in the narrow valley below, a total of about 163 million m≥. A flood wave of 6-8 meter height roared through the river valley as far as 30 km downstream, before it diminished in the widening floodplains of the lower Eder (near Kassel), the Fulda and the Weser.
The dam was rebuilt within months by forced labor (Organisation Todt), and the lake today is a major summertime recreational facility. It has a capacity of 240.3 million m≥, which makes it the third largest reservoir in Germany. It is a very popular summertime recreation area.