How much Water is there?

'Before the dawn of civilization, there were 326 million trillion gallons of water on the Earth. Unlike other natural resources, we cannot run out of water. With over 6 million people, we still have 326 million trillion gallons of water." GOOD magazine, Summer 2009

" If all Earth's water fit in a gallon jug, available freshwater would equal just over a tablespoon - less than half of 1 percent of the total. About 97 percent of the planet's water is seawater; another 2 percent is locked in icecaps and glaciers. Vast reserves of freshwater lie under the Earth's surface, but much of it is too deep to economically tap" - National Geographic Special Edition: Water -The Chaos of Supply, November 1993