I do not think that it is the Sorpe dam. Only one of the photographs has a location written on the back and it isn't Sorpe. All the photographs are from the same roll of film.
Soldiers of the Royal Tank Regiment sightseeing. They seem to be studiously ignoring the large piece of fallen masonry.
The photograph of the hydro power plant at the base of the dam identifies the dam as the Mohne...low head hydro runners within the penstock. At a water head of 32 metres when full,the dam electrical generation was a few MWs. When the Mohne dam was breached,the hydro power plant which was situated adjacent to the outer dam wall at the base of the dam was destroyed.Speer had the power plant rebuilt in its original location during the summer of 1943.It took four months to repair the dam and completion was in time for the autumn and winter rainfall.In 1953 the power plant was relocated further down on the south side edge of the outlet lake and here it remains recognised as being a typical industrial building. The precautions against air attack were put in place after the dams raid.The boom shown was installed to protect the dam face and was a precaution against torpedo carrying aircraft.The Germans went to the extent of installing contact mines on towers as a precaution against low flying aircraft. Ack Ack defences were improved.There is evidence of a gun plinth on the far side south end of the dam. Stefan with what I thought was a dam causeway.I thought it was the Sorpe.
There were indeed a great deal of defensive measures installed during the rebuilding. The roofs of the turrets have not yet been rebuilt.
Simon, one of my contacts from Dortmund sent me some more links of man made lakes in the area. Are you still searching for this lake? Stefan.
Stefan, thank you for your reply, I am not currently researching man made lakes in the Dortmund area as I believe we now know the location. Simon.