Requirement to declare flood risk?

I am about to go looking at a house in an area where I suspect there may have been flooding last year. I know some of the area was flooded, but as I'm not too knowledgable about the locality, I can't be sure where the dry parts were, and there were places around there that were quite untouched by floods.
My question is, when I'm viewing a house, is the agent required to declare flood risk/previous flood damage if I ask?

Thanks