1.3: Fresh Water Flows
Underground
Groundwater: Water held
underground
Permeable: A substance that liquids
can flow through. Ex: coffee filter,
soil, sand and gravel.
Impermeable: A substance that
liquids cannot flow through.
Ex: A drinking glass holds liquids
because it is impermeable.
Clay is soft, but it is nearly
impermeable.
Groundwater collects because
gravity causes rainwater to sink
into the soil. Water sinks though
permeable ground until it reaches
an impermeable layer.
Water table: The top of the area of
groundwater that is saturated or
completely filled with water. This is
called the saturation zone.
Groundwater may collect in the
spaces within soil, gravel and some
kinds of rock.
Aquifers
An aquifer is an underground layer
of permeable rock that contains
water. Some lie deep under
impermeable rock, and others lie
just beneath the topsoil.
3 Things Must Occur for an
Aquifer to Form: (pg. 26)
1. Groundwater is stored in the
pore spaces of gravel and rock in a
layer of permeable material.
2. A neighboring area of
impermeable rock keeps the water
from draining away.
3. A source of water refills the
aquifer.
Importance of Aquifers:
The ground acts like a giant filter.
Stones and sand in the ground can
filter out bacteria. It removes
harmful chemicals and minerals. It
keeps water cleaner and more
ready to drink.
Springs and Wells:
A spring is a flow of water from the
ground at a place where the
surface of the land dips below the
water table.
A well is a hole in the ground that
reaches down to the saturation
zone- the wet region below the
water table.
Most wells need a pump to draw up
the water and are dug with
motorized drills.
An artesian well does not need a
pump. The water flows to the
surface naturally because it is
under pressure.
The depth of the water table can
vary from season to season,
depending on the amount of
rainfall.
If water is used faster than it is
replaced, wells may run dry
causing the ground to settle and
damage the environment.
Hot Springs
Hot Springs- Hot water deep
underground that is like an
enormous boiling pot. Water heats
to the boiling point and then
becomes hotter because the liquid
is under great pressure from the
surrounding rocks.
A geyser is a kind of hot spring.