Flood isn't something that will occur randomly, your government should had warn the citizen for upcoming big flood. If I live in a country where extreme floods is nothing new, I would wear secret stash bracelet. Change the keys with laminated paper which I wrote my seed phrase, so it can resist against water.
No one will know if my bracelet contain almost all of my wealth.
https://www.yankodesign.com/2013/04/16/wear-your-secret-stash/This is a great idea to keep private keys safe, there is a very low chance that someone will lose bracelet or will become a victim of theft because it looks like a very cheap bracelet. I think Rings are also a good way to store keys safely. If you use a micro printer to print private keys and somehow attach it to the ring safely, it can be a good way.
So do you remember the terrible earthquake and collapse that happened in Türkiye and do you think there will be any technology advanced enough to know the full extent of mother nature's fury? It seems like you are trying to blame the government for the natural disasters caused by mother nature.
Erdogan arrested many building contractors because of that accident. The problem was that they were allegedly involved in shoddy and illegal construction methods. As far as I remember, the built quality was low and there wasn't a correct seismic analysis done.