Diemelsee
![](/Images/godic/202501/08/DiemelseeHelminghausen5659.JPG")
![Dam and power station from the north](/Images/godic/202501/08/Diemeltalsperre_Überlauf_20045659.jpg")
![View of St. Muffert over the Diemelsee](/Images/godic/202501/08/St._Muffert_-_Diemelsee5659.jpg")
The Diemelsee or Diemel Reservoir (German:Diemelstausee) is a reservoir with a surface area of 1.65 km² and about capacity of 19.9 million m³ on the River Diemel in the counties of Waldeck-Frankenberg in North Hesse, and Hochsauerlandkreis, Westphalia, Germany.