Lake Bigge

Lake Bigge looks as if it had always been there: a branching body of water between wooded Sauerland hills, with sailing boats, swimming bays and a protected island. In fact it has only existed since 1965, and whole villages lie beneath its surface. Together with Lake Lister it forms one of the largest reservoir systems in Germany and is now the leisure playground of the southern Sauerland.

History: a lake for the Ruhr

The dam was planned as early as 1938, but the war stopped it. Only from 1956 was the Bigge valley between Attendorn and Olpe flooded, financed partly through the "Bigge penny" that water customers in the supply area paid per cubic metre. The rock-fill dam was finished in 1965. Around 2,550 people had to move to newly built villages such as Neu-Listernohl, Sondern-Hanemicke and Eichhagen; their old villages were demolished and flooded.

The lake's job is still a practical one: it stores water so the River Ruhr carries an even flow to supply the Ruhr area, and it protects against floods. From November to February storage space is kept free for floodwater, and the lake refills in spring. A hydroelectric plant also generates about 22 million kilowatt hours a year. The operator is the Ruhrverband water association.

The lake in numbers

• Surface area: 8.76 square kilometres together with Lake Lister, around 20 kilometres long.
• Storage capacity: 171.7 million cubic metres, a good 150 million of it in Lake Bigge.
• Depth: up to about 52 metres when full.
• Gilberginsel: an island of about 34 hectares, part of a nature reserve.

Things to do

• Boat trip: Passenger boats run from the Easter to the autumn school holidays, with landing stages at the Sondern lakeside promenade, the viaduct and the Bigge dam near Attendorn. A round trip takes about 90 minutes. The MS Westfalen, built in 1978 with 750 seats, has run on electric motors since a refit in 2023.
• Biggeblick: This viewing platform from 2013 on a spur of the Dünnekenberg juts out over the slope like a skywalk. From here you see the dam, the Gilberginsel and the Waldenburg castle ruin.
• Swimming: Public bathing spots are at Schnütgenhof near Attendorn and Kessenhammer in Olpe. A large sandy beach with a beach club has been created in Waldenburg Bay. Water quality was rated excellent in 2019.
• Hiking and cycling: The 46-kilometre Bigge-Lister trail circles the lakes, and cyclists can follow the Lakes Route, around 50 kilometres mostly right along the shore.
• Water sports: sailing, windsurfing, rowing, paddling and diving, with two official dive sites.

Good to know

Along the lakeside path, information boards show what the Bigge valley and its villages looked like before the dam. The "Bigge penny" was only abolished at the end of 2009.

Visiting and getting there

By car, take the A45 to the Olpe exit. By train, go to Olpe and continue by bus. Half a day is enough for a boat trip and a walk; with swimming or a bike ride it becomes a full day. The Atta Cave in Attendorn is only a few kilometres from the dam and fits well into the same day out.

Tripto tip

Start in Attendorn at the dam, climb up to the Biggeblick and then take the boat. From the water you see the bays and the Gilberginsel from an angle you never get from the shore.