Just finished a thru, so my info for these segments is a couple weeks old, but I remember segments 18 and 19 being pretty dry.
I definitely walked by some crummy sources, so maybe I was just being picky.
I do think that the water through there was pretty evenly spaced though.
I was only using Aquamira, so I avoided some of the dirtier water and made it through just fine, but depending on where you're planning on camping this could be a factor.
Hope that helps.