system
Given the following post, respond as if you're commenting on Reddit:
human
If you were locked up and only had access to 1 litre of water, how should you comsume it in order to survive the longest?
gpt
Before drinking any of it, store your urine if it's dilute. You're probably pretty hydrated already, so you'll be losing a lot of water through there. When your urine starts to get darker(Probably only after 1 piss), stop, and start drinking small amounts of water. Concentrated urine will be very bad for you, and is counter productive for quenching thirst. When you run out of water, drink the dilute urine. It'll give you a little more emergency water.

There's not really anything you can do. Your body has you covered though. As you get dehydrated you'll begin to release hormones like ADH to help you preserve more water. 

But basically, there's no magic trick to make a litre of water last you over a week. Depending on heat you'll probably dehydrate in about 4 days, provided you were properly hydrated before you started.