I am disabled in the wildness, there are no natural water sources available. I have 2 gallons (7.5 liters) of water. The only practical solution is to sit and wait for rescue. I will be resting in the shade. How much water should I drink each day to survive as long as possible?
I have a memory from school that the kidney is obligated to produce 500ML of urine each day. That would seem to be lowest possible consumption.
I found a variety of amounts during an internet search.
With the possibility of urine output dropping to 500 ml, the minimum could be just over 1 liter a day or for the sake of making it easy to understand, this would be just over 32 ounces a day for a 154 lb man
A normally active person needs about three quarters of a gallon of fluid daily, from water and other beverages.
Absolute Minimum Requirements...for replacement purposes, for an "average" person, has been estimated to be approximately 3 liters (3.2 quarts) per day, given average temperate climate conditions.
one gallon of water per person, per day
a minimum of 7.5 litres per capita per day will meet the requirements of most people under most conditions. This water needs to be of a quality that represents a tolerable level of risk. However, in an emergency situation, a minimum of 15 litres is required
With daily consumption of 500ML (~ 1/2 quart) the water would last 2 weeks, but would I survive? A 7.5 liters (~2 gallons) the water would last a single day and I would die in about 3 days.
How much water should I ration myself each day?