Consider the drawing at the right: The three blue spheres represent respectively all of earth’s water, earth’s liquid fresh water and water in lakes and rivers.
~ US Geological Service (1879-03-03 age:139) source
All of Earth’s WaterThe largest sphere represents all of earth’s water and its diameter is about 1.38 megameters (857.49 miles). It would have a volume of about 1.39 cu megametres (332,519,083.03 cubic miles). The sphere includes all the water in the oceans, ice caps, lakes and rivers, as well as groundwater, atmospheric water, and even the water in you, your dog and your tomato plant.
Liquid fresh waterHow much of the total water is fresh water, which people and many other life forms need to survive? The small blue sphere over Kentucky represents the world’s liquid fresh water (groundwater, lakes, swamp water, and rivers). The volume comes to about 10,633,450 cubic kms (2,551,100.32 cubic miles) of which 99% is groundwater, much of which is not accessible to humans. The diameter of this sphere is about 273 km (169.63 miles).
Water in lakes and riversDo you notice that tiny bubble over Atlanta, Georgia? That one represents fresh water in all the lakes and rivers on the planet and most of the water people and life of earth need every day comes from these surface-water sources. The volume of this sphere is about 93,113 cubic kms (22,339 cubic miles). The diameter of this sphere is about 56.20 km (34.92 miles). Yes, Lake Michigan looks way bigger than this sphere, but you have to try to imagine a bubble 56.20 km (34.92 miles) high — whereas the average depth of Lake Michigan is less than 91 metres (99.52 yards).
The politicians of the world, such as Stephen Harper, on the take from mining companies, see that tiny sphere as their personal property. They believe its primary purpose is to dilute mining tailings and other industrial wastes or to process tar sands.