1. Water Systems

2. We know from the water cycle that
when precipitation falls, it will
eventually end up back in the ocean...
... either from our sewer lines, or
from rivers and streams.

3. But did you know that precipitation
from Montana can flow all the way
to Louisiana?

4. Actually, the water from nearly half the U.S. flows to Louisiana!

5. That’s because they are all part of
the same watershed!
A watershed is all the area that drains
out the same river to get to the ocean.
watershed

6. Watersheds are separated by a divide--
mountains that cause the water to flow
to one side or another.
divide

7. The water flows down small creeks and streams called tributaries...
That later join the larger, main river!
(the largest river system in the U.S. is the Mississippi!)

8. Of course we know that not all the
water from an area goes downstream...
Some of it stays trapped in
lakes or ponds...

9. And some of it seeps underground!
(This is called groundwater)
groundwater

10. The dirt and small rocks have small holes called pores in them, which
make them permeable.
permeable
layers
This means water can pass through!

11. When there are no more cracks or pores for the water to pass through,
it has reached an impermeable layer.
impermeable
layer
This means the water can’t go through!

12. The water starts to collect into an
underground pool called an aquifer.
aquifer
People used to believe they could find
aquifers using dowsing or divining rods!

13. The layer that is full of water is called
saturated. It can hold no more water!
saturated
The layers that can still absorb
more water are unsaturated.
unsaturated

14. When the unsaturated layers begin
to get saturated, the water level begins
to rise.
water table
This level is called the water table.
water table

15. When the water table rises to above
the ground, the result is a flood!

16. If the water table is not high, we have
to dig a deep well to get to the aquifer.

17. But sometimes the water will come out
on its own because of built up pressure.
This can form a spring or artesian well!

18. And that’s all you need to know about
our world of water!
(for now....)