I am sure many people put their important documents in their "gun / fire" safe at home or in a safe deposit box at the local bank.

Although the "gun / fire" safe may be fireproof and splashproof to a certain degree. If your house or the local bank branch is under 2m of water. It is very likely that your important documents may be damaged by the flood water.

Please consider putting the important documents in a waterproof bag. Before storing the waterproof bag in the safe.

Cheap alternative to a waterproof bag would be the zip lock bag. Put items into 1st zip lock bag, then place 1st zip lock bag into 2nd zip lock bag.