Board Thread:Help Desk/@comment-24027791-20131008175900/@comment-26440657-20160819110100

Why do you need it gone? I'd turn it into an underground fishing spot if it were me, or a water source or an obsidian generator.

Anyway, it doesn't look that big to me, if I just want the water gone I'd blast it to hell. You could fish until you get the Super Absorbent Sponge but that would take a while. If you want it to be useful, you can do what the others said and pour lava on it then mine the obsidian, that wouldn't waste the water.