From what I was led to believe by the owner, both the field next door and ours "dip" in the middle and normally flood there. In each dip is a natural spring (which we can draw water from all year). A beck run's at the back of the fields and a large drainage ditch just in front of the fields. In theory, both field should drain from the center into the drainage ditch (our field has a mini ditch dug along which we kept free flowing throughout).
Our field is about a foot (ish) higher than next door's where the boundary's meet and about three foot higher overall.
The problem seemed to be that the beck had not been cleared, so was running into next door's field. He also hadn't maintained any of his ditches, so they are all full of reeds/weeds/tree branch's and flowing slowly.
This meant that the entire field became a lake and began to raise the water level in our field. Eventually, it was flowing over the boundary (and I think raising the water table), into our field.
We have gone over to the area's with a public footpath and cleared everything we could (including a motorbike engine) out of the beck. This is now only trickling into next doors field and our flooding has receded dramatically. We have just an inch or two of water where we have about 2 foot! It is by no means dry, but is looking like a field rather than a lake.
Unfortunately, it looks like we are going to have to maintain the entire beck through both our field and next door's to make our field usable in this dreadful weather
Oh, and we had to buy chest waders for hubby so he could clear the beck (at least he didn't fall over!).