I embarked on a rocky wasteland with an aquifer. Its 8 levels deep and immediately below it is a large flooded cavern. I have no wood and not a lot of room to work with.
On the plus side, if I can set up an underground tree farm or find more coal I've got access to more iron than I know what to do with, as well as flux stone, clay, and sand. The location has a lot of potential, its just a hell of a fixer upper.
My initial plan was to wall off my tree farm to prevent flooding from the (light) aquifer, but I think setting up several floor drains would work better, allowing me to dig my farm deeper and larger without much additional effort.