My recurring dream since childhood.

Floods.
I used to have this same dream, not every night, but it was often enough that I could wake up and remember and think, its the same dream.
I would be looking out of a window in the house where we could see fields and they would be filling with water in the distance. The water would gradually be drawing nearer and nearer.
These dreams eventually stopped happening so frequently, having moved on with my life, with my own family, however every now and then, the flooding dreams would return in one form or another.

Then, a few days ago, WHAM, the flooding dream to end all dreams. The world had been submerged, literally, the sea level had somehow raised so that all civilisation was now a sunken memory. I was aboard some kind of structure that had survived this onslaught. I would not call it a ship as we know it, but it had somehow survived and remained afloat. All around as far as the eye could see, where once had been cities, there was now water.
And then, in the distance, a giant wave raced across the horizon towards us. This was it, in my dream, we were done for.

And then I woke up. My question is, assuming this happened, where would all this water come from?

funny you mentioned it, I cant really remember flood dreams in my early days.
But I did had a flood dream twice in a row some months ago, I was in my house with my family then went outside to sit there, then in the horizon I could see a HUGE WAVE of water coming towards us at a tremendous speed, I felt it coming and I knew I was going to die, so I saw it nearing almost to fast to see and closed my eyes and waited for impact.

Then I got hit in the dream and felt a strange pain sensation all through my body and tickling feelings and weird sound.
Then I woke up..
A day later I got the EXACT same dream! but with other people!

It felt different then other dreams very real and plausible.

Thats the problem....theres not enough water on the planet to cause a worlwide flood of any kind of magnitude.

People are always bleating about the ice shelves melting....well a huge chunk did, thousands of square miles simply melted into the sea...yet sea levels remained pretty much the same worldwide.

Theres not enough water on the planet to submerge entire continents

I had a quick look into 'dream meanings' to see what it says and found this:

Flood Dream Meaning

Psychological Meaning: Water symbolises the emotional side of the unconscious. To dream of a flood or being swept away by water, indicates that you feel emotionally overwhelmed. These dreams also hint at baptism and rebirth. The fertile, nourishing effect of floodwater may be implied. This dream could therefore represent the start of a new phase of life and renewed personal growth.

Mystical Meaning: The story of Noah, the Epic of Gilgamesh and other myths about floods represent a purging that prepares the way for something better. Everything in your life has been swept away so that you may start anew.

Link here....

However, I am not convinced that all dreams have any deeper meaning for us other than our brains acting out during rem sleep; however, if any of the above fits for you.....

I would have to be feeling pretty darn desperate to find some sort of doom-and-gloom prophecy to get all worked up about before I'd buy into the possibility of a worldwide flood.

There is an extreme scenario ... that, if the Earth were somehow, to swap axis in a small space of time .. say, 1 day .. ie, north pole shifted to south pole .... then, the slither of water that covers our planet, would easily flow or glide across continents, at its leisure ... until settling again ...

In that scenario ... there is enough water on the planet, to cover 'most' of the planet in water, during the manoeuvre ... It doesnt have to cover the entire globe simultaneously .. but can leave practically no part of the entire globe untouched, during the shifting of water ..

Not to be confused with the Earth magnetic field switching north to south ... for the above scenario, the entire earth would have to shift ...

Some believe this has already happened to our planet before ..
Some believe it is possible for this to happen to our planet, after a magnetic pole shift .. Though if so, i'm not convinced it could achieve it in such a small space of time ..

Also, potentially, a passing heavenly object, with enough mass, close enough to earth could affect the Earths rotation enough to cause a similar outcome as poles switching above ...

I don't really have a belief as to how it can happen .. but i do believe it can happen ...
The bible aside .. there is plenty of other evidence to suggest there was at least once, a great, world wide flood.

This may be of interest to you ...