IT USED TO HAPPEN IN THE PAST The problem remains: Dubrovnik was facing a flood in 1919. as well
Local people from Dubrovnik often show their dissatisfaction when it comes to the water draining system and they are absolutely right that it is still far from perfect. Nevertheless, it seems this problem hasn't appeared recently as there is an obvious evidence.
There was published a photo in a Facebook group called 'Dubrovnik Before' and the photo shows how the floods used to be something that was very common to happen before as well. The photo was captured in 1919.