Water Underground
Section 5
Pages 68-74
Underground Layers
Where does underground water come from?
 Do you recall what happens to precipitation
when it falls to Earth?

Precipitation
falling
to Earth…
evaporates
immediately
runs off the
surface
soaks into
the ground
Underground Layers
 The
rain water that soaks into the
ground trickles downward, following
the pull of gravity.
 What
happens
when you pour
water into the
pitcher of
pebbles?
Underground Layers
The water will trickle down around the
pebbles until it reaches the bottom of the
pitcher. Then the water will fill up the
spaces between the pebbles.
 In the same way, water underground
trickles down between particles of soil and
through cracks and spaces in layers of
rock.

Pore Space
Different types of rock and soil have
different sized spaces, or pores, between
their particles.
 How easily water moves through the
material depends on:



size of the pores
whether or not the
pores are connected
Permeable
 Materials
that allow water to easily
pass through, or permeate, are
called permeable.
 Examples: sand and gravel
Impermeable
 Water
will eventually reach layers of
material that it cannot pass through.
These materials have few or no
pores or cracks for water to flow
through.
 Materials that water cannot pass
through easily are called
impermeable materials.
 Examples: clay and granite
Permeable vs. Impermeable
Trapped Water!
Once water reaches an impermeable layer
it is trapped! Where can it go?
 The water will start to fill up the spaces
above it, the permeable layers it just
soaked through.

More Vocabulary
saturated zone = the area of permeable
rock or soil that is totally filled, or
saturated with water
 water table = the top of the saturated
zone (where you dig to strike
groundwater!)
 unsaturated zone = the layer of rocks
and soil above the water table (the pores
here contain air and water)

Words Worth Knowing (ISN#55)
pore
 permeable
 impermeable
 saturated zone
 water table
 unsaturated zone

Underground Water Part 2
Aquifers
Any underground layer of rock or sediment
that holds water is called an aquifer.
 The water in an aquifer is in motion,
seeping through the layers of rock.
 Speed of the water is determined by:



Slope of aquifer
How permeable
the rocks are
Porosity Gizmo http://www.explorelearning.com/

Two students are given cubic boxes
measuring 10 cm on a side. Patrick puts a
single glass marble with a diameter of 10
cm in the box. Susan puts 1,000 1-cm
glass marbles in her box.
Q. Whose box has more empty space?
Explain.
Q. Whose box will be heavier? Explain.
Aquifers
Aquifers can range in size from a small
underground patch of permeable material
to a HUGE area the size of several states.
 Millions of people obtain their drinking
water from the Ogallala aquifer.

Aquifers

Ogallala Clip, Kansas Farmers

https://www.youtube.com/watch?v=XXFsS94HF08
Bringing Groundwater to the Surface
The level of the water
table generally follows
the shape of the
underground rock
layers.
 The depth of the water
table can vary greatly
depending upon the
weather.

Bringing Groundwater to the Surface

How does water actually get to the surface?



In places where the water table meets the
ground surface, water seeps onto the surface.
The groundwater may feed a stream or pond, or
form a wetland.
People can also bring groundwater to the
surface.
Wells
People can obtain groundwater from an
aquifer by drilling a well below the water
table.
 Long ago, people dug wells by hand and
used a bucket to bring up water.
 Today, most wells are dug with well-drilling
equipment with pumps bringing the water to
the surface.

Wells
Can a well run dry?
 Yes! Pumping too much water out too fast
can cause the well to run dry.
 What can you do if it runs dry?
 Either dig deeper or wait for the aquifer to
recharge (rainfall).
 Recharge = new water that enters the
aquifer from the surface

Artesian Wells

www.youtube.com/watch?v=KMtEQqbi4CI
Artesian well = a well in which water rises
because of pressure within the aquifer
 There is a great deal of pressure on water
that is trapped between two layers of
impermeable material. Puncture the top
layer and you strike water!

Springs
Springs = where groundwater bubbles or
flows out of cracks in the rock
 Groundwater can seep, flow or erupt onto
the surface.
 Water is usually at normal temperatures
but some springs contain warm water that
has been heated below the surface.
 Yellowstone has hot springs. Also, Warm
Springs, Georgia and Hot Springs,
Arkansas do too!

Geysers
Geyser = a type of hot spring from which
the water bursts periodically into the air
 Geysers form when very hot water deep
underground begins to rise through cracks
in the rock. Heated gases and bubbles of
steam are forced up by the pressure of
the hot water.


https://www.youtube.com/watch?v=_gyhvqbIaOE
South Lyon, Michigan
South Lyon Aquifer

The City of South Lyon's
water system is serviced by
three (3) wells ranging in
depth from 120 to 125 feet
deep. They have a one
million gallon ground
storage tank with a 500,000
gallon elevated water tower
which supplies water
pressure to the City at 6070 psi.
Huron River Watershed

Credit http://www.southlyonmi.org/1/223/water.asp

*this is not the
South Lyon water
tower
South Lyon Aquifer

Mr. Bob Martin and his crew

http://vimeo.com/63817554
Words Worth Knowing (ISN#55)
aquifer
 recharge
 artesian well
 springs
 geysers


You should have 28 words worth knowing