The waters from the great flood story of Noah came when God opened the floodgates of heaven and let the great ocean of water above the firmament poor onto the Earth. At the same he opened up the deep springs and let the great ocean of water under the Earth rise up.
That is what the Bible says! Read your Bible before preaching it to others. Or better yet stop preaching it all together.
(As a little bonus, I'll let you in on a little secret. The aren’t and never have been great oceans of water above the sky (fermament), nor has there ever been a great deep of ocean water below the Earth.)
You are appealing to knowledge you can't possess. No one alive can say what was or wasn't before the Flood. At least you got the part about where the water came from correct.
