Lake Baldeney is located south of Essen, along the navigable part of the River Ruhr. At the time of its completion, its storage capacity amounted to approx. 8.3 million cubic metres. Over the years, and as a result of its function for river purification, its bed was subject to increasing sedimentation.
In 1981, after almost 50 years of operation, the lake’s storage capacity had shrunk to no more than 6.5 million cubic metres, despite a slight increase in volume as a result of mining operations, which lowered its bed. Planning for dredging started as early as 1968.
Dredging works began in April 1983 and were completed in May 1984. A total of 1.1 million cubic metres of sediment were removed from the lake using a flushing dredger. The removed sediment was transported over a distance of 7 km via a pipeline and deposited on silt fields. After the dredging operation, Lake Baldeney regained a storage capacity of 7.6 million cubic metres.
The weir in Essen-Werden has three openings with roller gates.
The hydropower station uses a mean water head of 8.7 m. A lock is located between the weir and the power station, enabling vessels of up to 38 m long and 5.20 m wide to pass through. As commercial navigation no longer exists, the lock serves "White Fleet" (Weiße Flotte) ferry boats and recreational craft only.
A nesting site for numerous bird species
The Heisingen bird sanctuary on the upper end of the lake has increased in importance over the years. Today, numerous bird species, such as the great crested grebe, grey heron, cormorans, kingfisher, crakes and different duck species breed in a marsh not accessible to visitors.