In World War II, the Sorpe Dam was among the targets of the British airstrikes of "Operation Chastise" in the night from the 16th to the 17th of May, 1943, as were the dams on the Eder and Möhne. In these attacks, the Royal Air Force attempted to destroy the dams using bouncing bombs, achieving at least one direct hit on the Sorpe Dam. According to the BBC 'Dambusters Declassified' the bomb used on Sorpe was not to spin as it was dropped on the dam rather than on the water and had no need to bounce. However, while the older arch-gravity dams of Eder and Möhne were successfully breached, causing a catastrophic flooding of the Ruhr valley, the Sorpe's embankment dam with its concrete core covered in soil withstood the attacks with only minor damage. The planners of the Operation had estimated that it would take 5 of the bouncing bombs placed correctly to weaken the dam sufficiently for water pressure to complete the break. The attacks also had to be made parallel to the line of the dam rather than perpendicular. A second British airstrike on October 15, 1944 with five-ton Tallboy bombs also failed, leaving behind only several huge craters and causing minor spillage.