Decommissioned reservoir. Near Aldershot, Hampshire.

[Antar]

The National Library of Scotland has a composite image of 1944 - 1950 air photos as well as their fantastic selection of maps.
1944-1950 view of the reservoir

 

[night crawler]

The National Library of Scotland has a composite image of 1944 - 1950 air photos as well as their fantastic selection of maps.
1944-1950 view of the reservoir

Not sure if that is what the guy wanted but you are right it is a hell or a resource to reference
Simon CG you could try looking at one of the local history groups

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