With how fast the person dies of things, was this a colony of hummingbirds? I don't mean that in a bad way. Just an interesting sci fi way as hummingbirds need to drink a lot in one day or else they die.
I don't think the time it takes you to do things is really canon. It's more from a game design perspective. While I also think it is very odd how fast you dehydrate, you should think more about how it takes around 3 minutes to drive to different facilities when, in real life it would take hours or even days to do so.