A full page advert in todays Guardian, placed by the Environment
Agency, exhorts readers to 'Act Now. Be prepared for flooding'.

Do they know something...

Not a lot. I saw the advert. The street in the photograph has quite a
slope on it so is unlikely to be at risk from flooding. But the idea of
publicising a warning is sound. Flood plains are given that name for a reason.
"River, stay 'way from my door".

Tudor Hughes, in unfloodable Warlingham, Surrey.