In 1927, the Ruhr Reservoirs Association (Ruhrtalsperrenverein) took over the Henne Dam and Reservoir built on the Henne River between 1901 and 1905 by the Upper Ruhr Reser-voirs Cooperative (Talsperrengenossenschaft der oberen Ruhr). Its masonry dam was 38 metres high and impounded eleven million cubic metres of water. However, it was decom-missioned for safety reasons in 1949 and was replaced by the new Henne Dam and Reser-voir with a storage capacity of 38.4 million cubic metres in 1950-1955. The Henne Reservoir serves to ensure water supply, flood protection and hydropower generation and is used for recreational purposes. The main reservoir contains two bathing areas and a diving spot with a maximum depth of 30 metres. The preliminary reservoir at Mielinghausen offers another bathing area. Several rowing and sailing clubs are located on the banks of the Henne Reservoir.