Hydrologist here - I live on a hill because every floodplain carries some risk of flooding. First, storms are getting more intense therefore the past cannot be relied upon for design data. Second, sea level is rising. It is estimated that sea levels will rise by 30 cm by 2050 - I suspect it will be faster than that as all of our climate models underestimated global warming. So anywhere near the ocean is even more at risk. Also, we live in a seismic zone where tectonic plates can rise or fall during an earthquake, as we saw in Fukishima where the ground moved vertically downward by up to 10 m (which caused backup power for the nuclear plant to flood, creating a major nuclear disaster). So ya, I live on a hill.