That leaves just one percent for all of humanity'a needs - all its agricultural, residential, manufacturing, community and personal needs. Water regulates the Earth's temperature. It also regulates the temperature of the human body, carries nutrients and oxygen to cells, cushions joints, protects organs and tissues and removes wastes. A person can live a month without food, but only about a week without water.
Water is part of a deeply interconnected system.
What we pour on the ground ends up in our water and what we spew into the sky ends up in our water. The average total home use for each person is about 50 gallons a day. Each day, the sun evaporates a trillion tons of water. In some deserts, rain is so uncommon that the natives do not have a word for it. The koala bear and the desert rat do not drink water.