If you are concerned about future floods it could be an idea to look into decking floor tiles. As its generally used for outdoor purposes it should handle a flood without issue.
Another benefit would be that it will leave some air gaps letting the concrete breathe, trapped moisture after a flood can create some real issues.
This is the type of tiles i'm referring to: https://www.amazon.co.uk/FAMOUS-Click-Deck-HARDWOOD-Decking-Tiles/dp/B00OA47LOA/ref=sr_1_5?keywords=hardwood+decking+tiles&qid=1571152770&sr=8-5This is the type of tiles i'm referring to.