The monarchy has been hated since it was reestablished. Pre-referendum times, there are soccer final (la copa del Rey) between Catalan and Basque clubs, giving the back and whistling so hard to the Spanish anthem, that the Spanish National TV disconnected the live sound and played the hymn on top.
There are also public cases of prosecution against people burning pictures of the (former) king, for a very useful law there is called “injurias contra la corona y la bandera”. And so on.
After Franco, they didn’t do a referendum about the monarchy established by Franco because polls told they may lose it, in favour of a republic. You know, the so called “Democratic transition” was more of a “transaction”. Same Police, same judges, same symbols, same politicians, same richmen.
Btw are you confusing Catalunya and València? How do you relate the referendum with the floods management? I don’t want to sound harsh, but I suspect confusion and reductionism >.<U