(CNN) — We don’t yet know how heavy a blow Hurricane Isaac will deliver to the Gulf Coast when it hits. But mindful of the devastation that Hurricane Katrina left in its wake, Alabama, Florida, Louisiana, and Mississippi have declared states of emergency and evacuations have begun. Public officials and emergency managers are getting good at getting people out of harm’s way.

But it’s making communities safe enough for residents to return to quickly that is so important, because packing up and running away from the weather is so expensive. The average Gulf Coast family fleeing the storm will have to dole out and estimated $250 to $300 a day for food and lodging.