Did the duplex you're selling really only flood once?

[Richard Miller]

So I found a duplex I'm interested in but noticed sandbags laying around so I asked the realtor if the duplex had ever flooded she stated it did in 2016 during a once-in-a-lifetime rain. Because it's in a rural area I'm having trouble finding out if it has flooded in the past. Can anyone give me guidance on where to research if this has flooded more than once?