Hi David
I'm reading a novel at the moment by a fellow author, Christobel Kent, called A time for mourning.
It's set as her books are in Florence and is based over a course of a week during very heavy rainfall and the famous Florence flood you speak about is recounted throughout the book.
Having visited and fallen in love with Florence , as you say it is quite outstanding but like many natural disasters quite fascinating, to see the photos and the plaques on walls  showing the height of the water.

Thanks for bringing it to our attention at a time that must bring very sad memories to a lot of the older generation of Florence inhabitants.

Have a great weekend and hopefully a dry one !
Thanks
Geoff