It's not just the water that does the damage, it's all the stuff that the water is carrying... like tree trunks and parts of your neighbor's house.
Along the Mississippi coast, although there is obvious wind damage to trees and roofs far inland, there it a stark difference when you get with a half-mile or so of the beach.
MSNBC.com has an interesting "blog" titled "Rising from Ruin", which features photos of the Waveland and Bay St. Louis areas.
This was the L&N railroad bridge, right where the Gulf narrows into Bay St. Louis. Notice the steel rails bent back with crossties still attached, looking like fence. The only wind damage that can match that would probably be associated with a nuclear blast.
I hear they are thinking that bridge may be repaired by March. Wonder how accurate that assessment may be?