Sorpe is a river of Hochsauerlandkreis, North Rhine-Westphalia, western Germany.
Map of Sorpe, Sundern, Germany
It is a left (western) tributary of the Röhr, which is a tributary of the Ruhr. The Ruhr is a tributary of the Rhine.
The Sorpe Dam is located on the Sorpe forming the Sorpe Reservoir. It is located near the small town of Sundern.
References
Sorpe (Röhr) Wikipedia(Text) CC BY-SA