Extreme weather events are increasing. Also, the construction itself may increase the risk of flooding (less permeable ground, so more run-off) even if well thought-out and well built.
You could check the planning permission for conditions and requirements relating to flooding, but that is not foolproof. Also, if construction is still going on, you could try to find the construction engineer for the project for discussion of what's been done and whether it is adequate - would the construction engineer buy here?
Personally, I'd avoid any building in a flood zone if I had other options available.