Floating down the Yellowstone River recently, it was very noticeable the water was low because there were rocky banks as big as a football field. In higher flows, like during spring runoff when snow in the mountains is melting, these rocks were underwater.
All of those exposed rocks made me wonder how much of a stream flows underground. According to scientists at the U.S. Geological Society, most water is moving underground — usually downhill, just like in streams. About 30% of freshwater on the Earth is located underground. Glaciers and ice caps have about 69% of water locked up, for now.
There are some places where underground water will stop or is slowed down, like in caverns. Mostly it is moving slowly around rocks or through the soil, filling holes like in a sponge. This underground water is the source of drinking water for many people. They get to it by drilling wells and then piping it to the surface.
Small springs may bubble to the surface in fields or mountains. I remember seeing one that thrashed about like a washing machine was churning the water.
Out of all the water in the world, only about 2.5% is freshwater that we could clean to drink. Most of the Earth’s water — 96.5% — is in oceans.
Especially in dry years like this one, we can appreciate the importance of water — and conserving it — even more. It is also a good reminder that we need to be careful about what flows into our waters, since it is so important to all life on Earth.