It's not posh down on the flooded plotlands.

It's a popular misconception that all of the Thames Valley is a posh area populated in the main by  stockbrokers and rock stars. But it's not all like Henley, Marlow and Cookham. Further downstream, the places that we are seeing on the news every night, Shepperton, Chertsey, Sunbury, are far from affluent and are in fact old plotlands where the shacks have been partly replaced by brick built bungalows. It's a neck of the woods that I know quite well from my time working on the river. The eccentric, marginal world of the plotlands is best recorded in Colin Ward and Denis Hardy's wonderful, Arcadia For All.
People built in places like Jaywick, Canvey Island and the floodplain of the Thames because the land was cheap and it offered the opportunity to have a little place of your own in the country. The old former plotlands are many things but posh and affluent they are certainly not.