About Bigge Dam

The Biggetalsperre in North Rhine-Westphalia is the largest reservoir in the Sauerland region, holding 171.7 million cubic metres when full. Completed in 1965 by the Ruhrverband, the 49-metre dam impounds the Bigge and Lister rivers in the hilly Sauerland highlands southeast of Attendorn. The reservoir was created primarily to secure water supply for the densely populated Ruhr industrial belt — at the time of construction the largest single water management project in Germany, displacing three villages and the town of Alt-Listernohl. Today the Bigge supplies drinking water to roughly 800,000 people in the Märkisches Sauerland. Adjacent to the main reservoir, the smaller Listertalsperre acts as a pre-reservoir and quality management buffer. The Biggesee, as it is locally known, has evolved into one of the most popular water sports areas in western Germany, with over two million visitors annually sailing, windsurfing, and kayaking on its 3,000-hectare surface. Boat excursions and cycle paths around the 60-kilometre shoreline are major tourist draws. Water quality is strictly protected under the catchment protection ordinance (Wasserschutzgebietsverordnung) for the Bigge, and certain shore sections are designated nature reserves for breeding waterbirds. The Ruhrverband monitors water levels, turbidity, and biological quality indicators continuously, publishing results on its public data portal.