Your body is two-third water, 60 percent of bodyweight and 70 percent of your muscle weight is water. Water helps regulate and maintain your body temperature; transports nutrients and oxygen; cleanses your body from toxins and pollutants; moistens and lubricates your mouth, eyes, nose, hair, skin, digestive tract, and joints; controls your appetite, cold water increases metabolism, utilizes water-soluble vitamins.
The required amount of water intake should be around 0.66 times your lean body. So you should consume atleast 10, 8-ounce glasses of water per day.