There was a SF / fantasy series that was set in the Mediterranean basin during the dry years - The Gandalara Cycle by Randall Garrett and Vicki Ann Heydron IIRC. I remember reading and liking the series when I was younger (though it’s not great fiction by any measure). The last book ends with the flood waters pouring through Gibraltar and the Gandalarans scrambling to get out of the hole.
I thought that was “The Golden Torc”?