We just had a "once every 100-years" storm surge last fall. Many islands in the southern Danish archipelago were not properly prepared and saw their dikes flood (including my birthplace, and yes, I know others have so much worse conditions, but we are/were rather well protected here in the Baltic sea). There was some damage, not least to some endangered species habitats that the Copenhagen zoo was keeping, and many islands will have to seek an exception with the cultural preserverance agency to be allowed to repair their dikes.

On the bright side, the flood has seen to the fire and flood equipment being checked, meaning that we now have proper portable flood pumps. Even though they at first sent pumps too large to be loaded onto the ferry. Derp. :)

Hopefully this will not repeat for another 100 years, but many of us islanders are not so sure with global warming, so we might have to evacuate and give up the smaller islands within my lifetime if such floods become a common occurance.

And of course we could just replace our 200+ year old dirt and stone dikes and less old water locks with modern concrete and steel dikes, but I think we'll have a hard time convincing the state to put in the required resources for a <10 people community. Even Ærø, one of the larger islands with a population of ~6000, has had problems with dike maintenance.

I guess my advice would be the normal stuff: keep some bottled water and long term food that can be eaten cold, keep a battery bank for your phone, blankets and a bucket, know how to get to your rooftop when in the attic (will hopefully never be necessary in the baltic sea), have a good pair of waders and a good flashlight. And of course, know how to quickly contact any other inhabitants in your local area if necessary.