The Ahauser Stausee reservoir is located below Attendorn in the Biggetal valley. It was built in 1938 to regulate the Bigge and has also served as a compensatory pond for the operation of the Bigge dam power plant since the Bigge dam was commissioned. The dam is created by an earth dam and a weir system, between which a power station is located. The weir has two flap gates and two fixed weir fields.
(Text: www.ruhrverband.de)