Above Rönkhausen lies the Pumpspeicherwerk Rönkhausen. It was built between 1964 and 1969. A basin (the upper basin) with a capacity of 1 million m3 was built on the Dahlberg. The associated lower basin is located 270 m lower on the Glingebach, and has a capacity of 1.3 million m3.
The water from the lower basin is pumped into the upper basin using cheaper nighttime electricity. When required, water from the upper basin is then discharged again through a 900 m long pipeline into the underground power plant at the lower basin, where it generates expensive electricity.