Victorian ground floor damp - external well

[Arundel1973]

We have a well (ragstone lined) just outside of our property (it's covered by the slab in the picture). The entire ground floor has rising damp. The previous tenants damp proofed and it came back. I have had the sewer pipes looked at and repaired. The damp doesn't cause spores but does destroy the plasterwork.

The well is empty as it has obviously been blocked up at some point. In the picture you can see what appears to be a slight sinkhole. As the land used to be a farm and we are on the incline down to the river, I wonder if the well was once filled by an underground stream. Since it has been blocked could we be getting the damp as the water isn't being drained away. Our attached neighbour does not get damp and neither do the other side.

I am at a complete loss as to who can help me check?

 

[Lacan07]

A high water table is just about the least obvious cause, especially if neither of your neighbours are affected.

Which walls are damp - external or internal or both? What construction are your internal floors - suspend timber or concrete / screed? How high is the external ground around the house? What plaster and paints have been used? (I spy the ubiquitous white paint job in the your photo).

These questions may well lead you to the answer.