Uhh... "those in the know" are the actuaries and if you were to take away the subsidies provided for homeowners and developers to deny basic mathematical facts, the entire area would be totally unbuildable already.
i work in insure tech, in the E&S space, which is where all of the flood and wind polices gets placed. Actuaries have nothing to do with it --- the cost of hurricane insurance comes from Moody's RMS and Verisk AIR, the only two CAT models the carriers and re-insurance companies use. Actuaries price the non-cat risk.
They can still get insurance for flooding?