It's not tidal here in Oxford either (well obvs, since we're further inland) but the meadows and what-not about half a mile from here are quite prone to becoming mud and I've ended up with significantly muddy feet as a result. Not good for running away from the killer cows that like to menace passers-by. Then there's Tewkesbury in the other direction which can be menaced by the Severn in various ways, including tides, all of which seem to result in mud. And as I mentioned earlier, the town I was born in on Tyneside, which was named after mud. There does seem to be a certain common theme, but I can't quite put my finger on it.