The “Obernautalsperre” (Obernau dam reservoir) is the larger of the two reservoirs of the Siegen-Wittgenstein Water Board. It has a capacity of 14.9 million m³. The catchment area of ??the drinking water reserve totals 21.5 km² of predominantly wooded and undeveloped areas on the western slope of the Rothaargebirge (Red Hair Mountain range). 365 people from four villages had to relocate for the construction of the dam.
The Obernautalsperre offers many recreational opportunities for those seeking relaxation. On a circular route that is approx. 8.5 km (around 10 km including the pre-filter basin) long and well-developed, hikers, walkers, runners, rollerbladers and cyclists can enjoy the peace and quiet and nature. Signs with information about the water and the dam, as well as information panels on nature and forestry if the region provide a wealth of information for interested hikers.
Obernautalsperre Dam is thus not only a drinking water reservoir for the people in the Siegerland and Wittgenstein, but also a unique local recreation area. The starting point of the round trip is the Obernautalsperre car park, where public toilets can also be found.