You do realize, of course, that properties flood all the time which haven't been identified as being in a special flood hazard area. You should never take the owners word on anything like that. If you want to reference what they know about detrimental property conditions, read the sellers disclosure. They can be held legally responsible for those statements. "Statements to Fernando", not so much. I would never volunteer to people that my experience indicates they don't need flood, landslide, earthquake or zombie insurance. If they are with me during my inspection & ask me, I will tell them what I know at that point, along with all the caveats and disclaimers appropriate to such information. But to just insert an unsolicited statement such as that into the report is much worse than making no statement at all.