Not all flood zones are created equal. Evacuation candidates should use common sense and not be panicked into a stampede because of a government power grab. Government loves to flex its muscles in natural disasters because it dreads having its incompetence and fecklessness exposed and because it feeds on the myth that no one can manage without the omnicompetent state.
During my hurricane stint..vehicle had water to top of engine but no apartments got water
Not everyone needs to evacuate..but if you own a home you should have a good idea if you are vulnerable