About Sorpe Dam

The Sorpetalsperre in the Sauerland district of North Rhine-Westphalia holds 70.4 million cubic metres and was completed in 1935 as part of the Ruhr catchment expansion programme. The 69-metre earth-fill embankment dam with a concrete core wall was, at the time of completion, the largest earth dam in Germany. It was the third target of the famous Dambusters raid in May 1943, but withstood the bouncing bomb attack because its construction type — unlike the concrete masonry dams at Möhne and Eder — absorbed the shock without catastrophic failure. The Sorpe supplies water to the greater Ennepe-Ruhr district and forms part of the Ruhrverband's integrated reservoir management network. The surrounding Sorpetal valley is a protected landscape area and a popular destination for hiking, cycling, and winter cross-country skiing. The 60-kilometre circumnavigation cycle route around the Sorpesee is particularly popular with families. Water quality is monitored under the EU Water Framework Directive as part of the Ruhr catchment plan, and the reservoir meets current drinking water quality standards. In dry years the Sorpe can be drawn down significantly as it acts as a strategic reserve buffer when the larger Bigge reservoir is at low capacity.