The largest sphere represents all of Earth’s water, and its diameter is about 860 miles. It would have a volume of about 332,500,000 cubic miles (mi3). 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. How much of the total water is fresh water, which people and many other life forms need to survive? The blue sphere over Kentucky represents the world’s liquid fresh water (groundwater, lakes, swamp water, and rivers). The volume comes to about 2,551,100 mi3, of which 99 percent is groundwater, much of which is not accessible to humans.