A
spring is any natural occurrence where water
flows on to the surface of the earth from below the surface, and is
thus where the
aquifer surface meets the
ground surface.
Formation
A spring may be the result of
karst
topography where surface water has infiltrated the Earth's
surface (recharge area), becoming part of the area
groundwater. The groundwater then travels though
a network of cracks and fissures - openings ranging from
intergranular spaces to large
caves. The water
eventually emerges from below the surface, in the form of a
spring.
The forcing of the spring to the surface can be the result of a
confined
aquifer in which the recharge area
of the spring water table rests at a higher elevation than that of
the outlet. Spring water forced to the surface by elevated sources
are
artesian wells. This is
possible even if the outlet is in the form of a 300-foot deep cave.
In this case the cave is used like a hose by the higher elevated
recharge area of groundwater to exit through the lower elevation
opening.
Nonartesian springs may simply flow from a higher elevation through
the earth to a lower elevation and exit in the form of a spring,
using the ground like a drainage pipe.
Still other springs are the result of pressure from an underground
source in the earth, in the form of
volcanic activity. The result can be water at
elevated temperature as a
hot
spring.
The action of the groundwater continually dissolves permeable
bedrock such as
limestone and
dolmite creating vast cave systems.
Types of spring outlets
- Seepage or filtration spring.
The term seep refers to springs with small flow rates in which the
source water has filtered into permeable earth.
- Fracture springs, discharge from faults, joints, or fissures in
the earth, in which springs have followed a natural course of voids
or weaknesses in the bedrock.
- Tubular springs are essentially water dissolved and create
underground channels, basically cave systems.
Spring flow

vertical
Spring discharge, or resurgence, is determined by the "spring's"
recharge basin. Factors include the size of the area in which
groundwater is captured, the amount of precipitation, the size of
capture points, and the size of the spring outlet. Water may leak
into the underground system from many sources including permeable
earth, sinkholes, and
losing streams.
In some cases entire
creeks seemingly
disappear as the water sinks into the ground via the stream bed.
Grand Gulf State
Park
in Missouri
is an
example of an entire creek vanishing into the groundwater
system. The water emerges nine miles away, forming
some of the discharge of Mammoth Spring
in Arkansas
.
Classification
Springs are often classified by the volume of the water they
discharge. The largest springs are called "first-magnitude,"
defined as springs that discharge water at a rate of at least 2800
liters or of water per second.
Some locations contain many first-magnitude
springs, such as Central
Florida
where there are 33 known to be that size, the
southern Missouri
Ozarks
(11 known of
first-magnitude), and 11 more in the Thousand Springs area along the Snake River in Idaho
. The
scale for spring flow is as follows:
| Magnitude |
Flow (ft³/s, gal/min, pint/min) |
Flow (L/s) |
| 1st Magnitude |
> 100 ft³/s |
2800 L/s |
| 2nd Magnitude |
10 to 100 ft³/s |
280 to 2800 L/s |
| 3rd Magnitude |
1 to 10 ft³/s |
28 to 280 L/s |
| 4th Magnitude |
100 US gal/min to 1 ft³/s (448 US gal/min) |
6.3 to 28 L/s |
| 5th Magnitude |
10 to 100 gal/min |
0.63 to 6.3 L/s |
| 6th Magnitude |
1 to 10 gal/min |
63 to 630 mL/s |
| 7th Magnitude |
1 pint to 1 gal/min |
8 to 63 mL/s |
| 8th Magnitude |
Less than 1 pint/min |
8 mL/s |
| 0 Magnitude |
no flow (sites of past/historic flow) |
Spring water content
- Main article: Mineral
spring
Minerals become dissolved in the water as
it moves through the underground
rocks. This may give the water flavor and
even
carbon dioxide bubbles,
depending on the nature of the
geology
through which it passes. This is why spring water is often bottled
and sold as
mineral water, although
the term is often the subject of
deceptive
advertising. Springs that contain
significant amounts of minerals are sometimes called '
mineral springs'. Springs that contain large
amounts of dissolved
sodium salts, mostly
sodium
carbonate, are called 'soda springs'. Many resorts have
developed around mineral springs and are known as
spa towns.
A
stream carrying the outflow of a spring to
a nearby primary stream is called a spring branch or run.
Groundwater tends to maintain a relatively long-term average
temperature of its aquifer; so flow from a spring may be cooler
than a summer day, but remain unfrozen in the winter. The cool
water of a spring and its branch may harbor
species such as certain
trout that are
otherwise ill-suited to a warmer local
climate.
Historic uses
Springs have been used for a variety of human needs including
drinking water, powering of
mills, and
navigation, and more recently some have been used for electricity
generation.
Modern uses
Present-day uses include recreational activities, such as
trout-fishing, swimming, and floating. The water is also used for
livestock and fish hatcheries.
Notable springs
- Big
Spring, Missouri

- Fontaine de Vaucluse
, France
- Giant Springs
, Montana
- Greer Spring,
Missouri
- Mammoth Spring
, Arkansas
- Maramec Spring
, Missouri
- Poland Spring,
Maine

- Rainbow
Springs, Florida

- Saratoga Springs
, New
York
- Te Waikoropupu Springs
, New
Zealand
- Wakulla Springs, Florida
- Warm Springs
, Georgia
- São
Lourenço, Minas Gerais, Brazil

See also
References
- Springs of Missouri, Vineyard and Feder, Missouri Department of
Natural Resources, Devision of Geology and Land Survey in
cooperation with U.S. Geological Survey and Missouri Department of
Conservation, 1982
External links