Hehe, LOLL.....
I've built a reef underwater on my piece of land (WELL, piece........ it's more than 12k sqm).......... Would be troublesome to find all my fish, corals and plants (let alone the megaprim ground textures) back if I would have to raise and then lower the land.
Used megaprims to lay over the water now and given them an ice structure, so problem solved, added a small snowstorm on my land as well. But thanks anyway