Earth's Fresh Water Resources

The Global Education Project notes that 97.5 percent of the water on earth is salt water, and only the remaining 2.5 percent is fresh water. In this small percentage, even less is available at the earth's surface in the forms of lakes, rivers and reservoirs. Most of the fresh water on earth is unattainable in the form of ice caps and groundwater.

Icecaps

• Global Change states that 70 percent of the fresh water on earth is frozen in the form of icecaps in Antarctica and Greenland. This fresh water remains stuck in its current position in the water cycle for long periods of time. While frozen, it is obviously of no use to humans.

Groundwater

• Large amounts of fresh water penetrate the soil to the point where it is unreachable. Groundwater can saturate every crack, hole and pore between rocks, sand and soil. An aquifer is a collection of groundwater that continually fills with water and is close enough to the surface for human use with some digging. Many people depend on groundwater in their everyday lives.

Surface Water

• Lakes, rivers and reservoirs are the Earth's available sources of fresh water. These sources make up less than 1 percent of the groundwater available on Earth. Renewed only by snow and rainfall, lakes, rivers and reservoirs are not large enough to be tapped for all human use. Doing so would create high costs to the natural environment surrounding the body of water.