Forgetting that water also moves diagonally when building my drowning trade depot chamber and putting the floodgate
like this I I
I I
I I_ _
IX_ _
So much FUN
I almost did that while build the the channel to my cistern. To avoid the fun of Building Destroyers and Lever Nuts, I was going to wall it off when it was full. It is in a dirt layer, so I've been constructing stone floors and walls to keep it from picking up mud on the way in. Of course, you can't build walls on floors, so I'd heave to deconstruct the floor to put up the wall, which would muddy the water. So I have to channel the floor, and put a wall in below to act like a floor, but this digs another hole into my storage level, so I needed to build more walls around it, so the water couldn't leak through diagonally.
It was like the four little flag stones scene from
Mr. Blandings Builds His Dream HouseAnd now an insane elf in a rope reed loincloth is chasing my cook around...