The Oleftal Dam

The Oleftal Dam was built between 1955 and 1959 in Hellenthal in the Eifel Hills above the town of Schleiden. It is one of only two columnar buttress dams in Germany, the other being the Linachtal Dam in the Black Forest. Uniquely, it consists of a chain of sixteen hollow columns, each of which is a self-contained static entity, that are connected by sealing elements made of sheet copper and synthetic rubber. In 1962 and 1982 the dam was strengthened with reinforced concrete. It contains 123,000 cubic metres of coarse vibrated concrete with greywacke rocks and sulphate slag cement.

The Oleftal Dam has an adjacent hydroelectric power station and retains around 33 million cubic metres of water a year from the Olef, Urft, Rur and Maas river basins. It supplies water and power to parts of Euskirchen district and the Aachen metropolitan area. In addition, the reservoir is used to balance out periods of high water with periods of drought. The dam is operated by the Eifel-Rur water utility (Wasserverband Eifel-Rur).

The “Wildwechsel” (Wildlife Variations) art project uses the entire valleyside wall of the dam, which is 282 metres wide and up to 59 metres high. The drawing that is being created with pressure washers covers roughly 8,000 square metres, making it the world’s largest picture.