Thanks for posting this topic originally, Timmer.

I've just stumbled across it again (while looking for something else, as usual!) and it reminds me that I previously found their location of that 'flooding' to be rather puzzling.
Nailsea & Backwell station is built on top of a quite high embankment, and the mainline tracks on either side are similarly raised significantly above the surrounding ground for some considerable distance. If you wanted to flood Nailsea & Backwell itself, you'd have to put most of North Somerset under water.

I therefore reckon that the flooding was actually towards Bristol, at Flax Bourton (which has previous for it, being down in a cutting) or possibly beyond Chelvey (towards Yatton). They maybe just located the flood as being 'Nailsea & Backwell' because that was nearest station to the actual location (although Flax Bourton used to have a station).
