Water Supply

We depend on fresh water from two main sources - surface water and ground water.

Surface water is the water found on the earth's surface such as oceans, lakes, streams, rivers, ponds and reservoirs. Of all the earth's surface water, 97 percent is too salty to drink because it's located in oceans and seas. Another 2 percent is locked in ice caps and glaciers. Only about 1 percent of the earth's water is fresh water to be used for agricultural, commercial, manufacturing, community and personal household needs.

Ground water is water that is found underground in rock formations, caverns and sand and gravel beds. Groundwater is pumped to the surface through a well, which may be hundreds of feet deep. When the pump is running, water is drawn in through cracks in the rocks and up the well shaft. The groundwater level (the "water table") drops when water is pumped, but is rises again when the rain soaks deep into the earth's surface to replenish the aquifer. In the United States, ground water is the source of water for about half of the population.