Some Hippy Site calls that (20L) the bare minimum per human per day.
I'm willing to call that negligible...
Goddamn, I'm a human, living in woodlands, it rains every other day here. There is water everywhere, hell, parts of my country are FLOODING right now... and I don't think I would drink 20L of water in a week. Serious. Adding up coke, coffee, energy drinks AND water... I think I'd only drink about 2L a day maximum.
We
are talking about the desert though, and I will admit, if you sweat more, you will drink more... but in the desert you would be working at night, and at night the desert gets bloody cold. In b4 'there is no day/night cycle in dwarf fortress', it wouldn't be that hard to arrange and I'm sure its been suggested 50k times before.
The major issue of Death Stills is that they are still a major source of disease anyhow.
If they were (which I'm pretty sure they wouldn't be), that would be another element you would have to manage. This is a good thing. Complicated is good.
I have to disagree and say that death stills ARE reasonable, but only to dispose of enemies corpses. To specifically breed animals for the purpose of extracting their water is obviously terribly flawed, otherwise if the energy transfer is from coal, then it really doesn't matter because that wouldn't be nearly as scarce a resource as water.
You wouldn't be breeding animals for the death-stills. You're right, the math just doesn't back that up. But you
would be hunting, and murdering goblins. Which, hell, you'd be doing that anyway wouldn't you?
You forgot that this refers to alive germs. Many bacteria, fungy and some Viruses can produce highly resistant spores. And getting such high temperatures would also a problem cause you would need "some" mirrors and/ or lenses for a deathstill.
edit: or plain fuel but who would burn wood in a Desert.
Anyway mirror-focused sunlight can melt steel so ....
*looks out over the sand*
Hmm, now where am I going to get some glass to make some lenses...?