Our daily need of water is mainly covered through drinking. On a daily basis we need to drink about 1,5 - 2 litres of water. Foodstuffs that have high moisture contents also contribute to our water supply. With our food we absorb about 1 litre of water a day.
Our total required amount of water is 2,5 litres a day. If we drink enough water and eat enough water-containing food, this should not be a problem.
How much water we drink is determined by our habits, not by thirst. When we feel thirsty, this usually is a sign that we have not been drinking a sufficient amount of water.