I've done construction work all my life-- after months of being submerged in brackish ( salt ) water, everything below the waterline will be mostly ruined.
Wiring- power & signal- will have to be removed and replaced.
Anything that can corrode, will. Think pipes, valves, steel, aluminum.
Most of a city's utilities are undergound-- pumps for water and sewage, as an example. All ruined.
Once you soak a pourous material ( wood, sheetrock, fabric ) in salty water, how do you get the salt out? If you don't, it continues to attract moisture from the air itself.
In my opinion, NO is largely insalvagable.
I hope that any Fedguv dollar that goes to rebuilding requires that the replacements of any utility equipment be salt water proof.