[choeger]

That thread points out some interesting observations about typical Star Trek inconsistencies (another one would be to think about why someone should move to a colony in the first place or rather about why not everyone can simply travel between planets as they like). But the objection against desalination is pointless. We can manage that problem already today (e.g., by drying up the brine or by pumping it into old oil wells). There is absolutely no reason to assume water would be scarce in the 24th century of TNG.