It's interesting, but the scoring is really esoteric. When I get "4 out of 6" on a level, there's not really any way for me to figure out what combination of watered/oversaturated/surplus would get me 6, so it becomes kind of trial and error. Not impossibly so, and it's still clear that you want to maximize some things and minimize others, but some transparency in scoring would help a lot, IMHO.