There are no "flukes" of nature when it comes to flooding, if it happened once it can happen again. Living alongside a river, especially in a coastal area it will happen again. If you are set on staying in the area, house raising probably is the best option. Sometimes raising just a few feet can make a big difference in flood risk. Your risk of experiencing a damaging flood of similar or larger magnitude will increase the longer you stay, so it is not a question if, but when will the next flood happen(are you listening PAPA HQ?).