Water Supply of the World
Updated February 21, 2017 | Factmonster Staff 
The Antarctic Icecap is the largest supply of fresh water, representing nearly 2% of the world's total of fresh and salt water. As can be seen from the table below, the amount of water in our atmosphere is over 10 times as much as the water in all the rivers taken together. The fresh water actually available for human use in lakes and rivers and the accessible ground water amount to only about one-third of 1% of the world's total water supply.
| Surface area (sq mi) | Volume (cu mi) | Percentage of total1 | |
|---|---|---|---|
| Salt water | |||
| The oceans | 139,500,000 | 317,000,000 | 97.2% |
| Inland seas and saline lakes | 270,000 | 25,000 | 0.008 |
| Fresh water | |||
| Freshwater lakes | 330,000 | 30,000 | 0.009 |
| All rivers (average level) | — | 300 | 0.0001 |
| Antarctic Icecap | 6,000,000 | 6,300,000 | 1.9 |
| Arctic Icecap and glaciers | 900,000 | 680,000 | 0.21 |
| Water in the atmosphere | 197,000,000 | 3,100 | 0.001 |
| Ground water within half a mile from surface | — | 1,000,000 | 0.31 |
| Deep-lying ground water | — | 1,000,000 | 0.31 |
| Total (rounded) | — | 326,000,000 | 100.00 |
1. All figures are estimated.
Source: Department of the Interior, Geological Survey.
