Freshwater is located in, on and above the Earth. It is found in freshwater lakes, rivers, swamps, creeks, estuaries, icebergs, glaciers and manmade reservoirs. Minute amounts of water are present in the atmosphere, in the soil and in biological organisms. Freshwater can also be found a few miles off the ground.
Nearly 97 percent of the world's water is saline or sea water, while freshwater or surface water makes up roughly 3 percent of the total water supply. Roughly 30 percent of this surface water is groundwater, while glaciers and ice caps make up the remaining 70 percent. Permanent ice located in the polar regions and mountain glaciers are the largest surface water storage in the world. Icebergs, glaciers and lake ice form from freshwater sources. Most icebergs and glaciers have been consistently solid for up to 15,000 years.
Billions of people around the world depend on groundwater as their main freshwater supply. The supply of groundwater is replenished by rain, snow, hail and other water sources that seep through the ground and move down into the water table. In the United States, freshwater sources are surface water or water from dams and manmade lakes. The water is generally treated and distributed as drinking water for public use, irrigation purposes and for use in the thermoelectric power supply to cool electricity-generating equipment.