You are so right. We've allways had water come in on high tides. The risk is hurricanes and storm surge, that is why flood insurance is so high on miami beach. (BTW its feels like hurricane frequency is in a downtrend) I just purchased a place on the intercoastal waterway in miami beach after selling my palce in west broward burbs. Flood insurance is around $2500 per year. Windstorm/Homeowners is $4500. Burbs was like 350 per year for flood.