A person can survive only three to five days without water, in some cases people have survived for an average of one week. It is not recommended that anyone try this at home. Once the body is deprived of fluids the cells and organs in the body begin to deteriorate.
http://www.thewaterpage.com/live-without-water.htm
The presence of water in the body could mean the difference between life and death. The human body is made from cells, bones, organs, and fluids. The functionality and longevity of the body depends on many factors. For instance, a person who goes without food and not water will live for quite a bit longer. This is because every organ in the body needs water to continue living.
http://www.thewaterpage.com/live-without-water.htm
After one day without food, the body will have used up its carbohydrates, which are stored as glycogen in liver and muscle cells. After that, it's on to the fat reserves. Your average Joe/Jane, weight-wise, has enough fat reserves to live for four to six weeks without food.
http://goaskalice.columbia.edu/answered-questions/one-cannot-live-water-alone
At that point, however, you can't really call it living since so much irreparable damage has been done to the body, including the brain. Bottom line: an average person could live for about eight weeks on water alone, give or take about a week for an over-or underweight person, respectively.
http://goaskalice.columbia.edu/answered-questions/one-cannot-live-water-alone
There are many factors that go into how long a human can survive without food and water, and the will to do so is one of them. Going without water isn't smart, and it doesn't take long before you're suffering from dehydration. Food is a different story. Humans can go quite a long time without food as long as they're well hydrated. Your body weight, overall health and the weather play into the scenario as well. So the answer to the question isn't easy and depends on the person and the situation.
http://adventure.howstuffworks.com/survival/wilderness/live-without-food-and-water.htm
In the 1940s, in one of the world's great acts of civil disobedience, Mahatma Gandhi went 21 days without food, surviving only on occasional sips of water. Gandhi was in his mid-70s at the time and thin as a reed. But he survived this hunger strike, by no means his first, without any obvious harm.
http://www.cbc.ca/news/canada/how-long-can-we-survive-without-food-or-water-1.1000898
You down a gallon of water like a land-bound carp and finish your day in the bathroom. At work, you may think you can't go more than a few hours without food and water. Sitting in a discount office chair in your cubicle is certainly no way to test your limits.
http://adventure.howstuffworks.com/survival/wilderness/live-without-food-and-water.htm
It's time for your co-worker to pay up! The human body can survive a surprisingly long time on water alone, but it is nowhere near six months. When the body is deprived of new fuel (i.e., food), it breaks into its energy reserves to keep going. The body stores energy in the form of carbohydrates, fats, and proteins.
http://goaskalice.columbia.edu/answered-questions/one-cannot-live-water-alone
The body needs at least 8 glasses or 64 ounces of water per day. This is to ensure that all the cells and organs in the body are being properly watered. When the body is given other liquids over a long period of time, the body may experience urinary tract infections, or bladder infections.
http://www.thewaterpage.com/live-without-water.htm
(Reuters). In general terms, the human body can go two to three days without water and, it is often said in survival guides, 30 to 40 days without food of any kind. (Many of these guides also discourage people from scavenging for wild plants or shrubs because of the adverse effects these can have.).
http://www.cbc.ca/news/canada/how-long-can-we-survive-without-food-or-water-1.1000898
how long can someone live without water
A person can survive only three to five days without water, in some cases people have survived for an average of one week.