Hurricane Gustav and Hurricane Ike caused flooding in many houses. When the water level of the flood is higher than the receptacles in your house, the receptacles must be replaced. Some areas, like St Tammany Parish, Louisiana, want you to replace just the devices while others, like in Orleans Parish, New Orleans, Louisiana, want both the wiring and devices replaced or everything that went underwater.
If you have cooper wiring in your house and it gets flooded, the wiring needs to be cleaned and dried. If it is aluminum, it is more problems. The metals in the receptacles are going to corrode and eventually short out. Romance soaked in water, with copper wiring, generally doesn’t have a conductive problem when it is submersed in water. On the other hand, it has to be dried out because of corrosive conditions that can occur.
A storm serge can cause salt water intrusion instead of fresh water. Salt water is more corrosive than fresh water. It can cause much more damage, sometimes to the point of replacing the whole electrical system. If that's the case, everything submersed in salt water must be replaced. This would include the panel, wiring, and devices. The whole electrical system. If it is submersed in fresh water, it can be dried out and cleaned to the point where the wiring can be used again, but all devices must be replaced. This includes replacing panels, disconnects and other electrical equipment like motors, pool pumps, well pumps, air conditioning systems.
I opened a panel this week that had salt water corrosion. I saw corrosion on the buss. And the breakers,too. Steel corrodes badly. And aluminum corrodes even worse. And it has been three years since Hurricane Katrina. Some people will say that they flooded and nothing happened to their wiring. It is not an overnight thing, it make takes years before something happens to your wiring.
If you flood, let a professional look at your wiring system. Do you know what your local code is concerning flooded receptacles?