We were always told in the PARA's to conserve water because what you carried was it!! and the time it took to boil water.
Would you believe many Britishsoldiers and units never realised that when you boiled water out in the ooloo, the smaller mess tin was designed to sit in side the bigger one to save the time it took to boil the water..................."another bit of useless information".
Other units of course had loads of water in Jerry cans so didn't probably care much about conservation or survival!!