A daily intake of 3-6 liters of water is required for the normal physiological functioning of the human body, depending on ambient weather conditions and diet (especially salt and sugar intake).
The absolute minimum over the long term is about 1.6 liters (600 ml for urine, 200 ml for fecal losses, and 800 ml for losses via the skin and lungs). This includes water contained in food (i.e., it is not essential to actually drink 1-2 liters of water a day for survival, though it is often recommended for good health....007