Commonly Asked Questions about Springs
A spring is a water resource formed when the side of a hill, a valley
bottom or other excavation intersects a flowing body of ground water at or
below the local water table. They range in size from intermittent seeps which
flow only after much rain to huge pools flowing hundreds of millions of
Springs may be formed in any sort of rock. Small ones are found many
places. In Missouri, the largest springs are formed in limestone and dolomite
(a magnesium bearing limestone) in the karst topography of the Ozarks. Both
dolomite and limestone fracture relatively easily. When weak carbonic acid
(formed by rainwater percolating through organic matter in the soil) enters
these fractures it dissolves bedrock. When it reaches a horizontal crack., or
a layer of non-dissolving rock such as sandstone or shale, it begins to cut
sideways, forming an underground stream.
As the process continues, the water hollows out more rock, eventually
admitting an airspace, at which point the spring stream can be considered a
cave. This process is supposed to take tens to hundreds of thousands of years
to complete. The age of a spring or cave is difficult to estimate due to the
variables of rock composition and water volume doing the work. Also, because a
catastrophic event may cause a rock collapse in minutes which would have
otherwise taken centuries, all age estimates are very general.
Most of the water in a given spring comes from the immediate vicinity;
all of it comes from what is known as the spring's recharge area. A
one inch rain on one acre of ground yields 27,192 gallons (.0421 second
feet)of water. Considering a 42 inch annual rainfall for Missouri, each acre
receives 1,142,064 gallons (1 .77 second feet) of water annually. Some of
this water runs off into surface streams and creeks, and some goes into the
In the Ozarks, a higher percentage goes directly into the groundwater
system than north of the Missouri River. Once there, some is stored and some
is released immediately by the springs. This accounts for higher springflow
after rains, and is known as surge flow. Base flow is that stored water which
is released more slowly, and keeps springs flowing even during drought. Many
tracing studies have outlined the recharge areas for the springs. This is
valuable information in case of a pollution spill which reaches the
groundwater of an area.
NO!!! The temperature of an Ozark spring comes from its passing,
through rock at the mean annual temperature of 56 degrees Farenheit. The water
temperature varies with the seasons and the rate of flow through the
underground channels, but except in times of flood or snow melt, it usually
varies only a few degrees above or below 56-59 degrees. The water is crudely
filtered in the rock, and the time spent underground allows debris and mud to
fail out of suspension. If underground long enough, lack of sunlight causes
most algae and water plants to die. However, microbes, viruses, and bacteria
DO NOT DIE just from being underground, nor are any agricultural or industrial
pollutants removed. While the water may be less contaminated than that from
an industrial river, no untreated water is truly safe to drink.
A column of distilled water is colorless. Various impurities, even
naturally occurring minerals, cause a column of springwater to reflect light
as greenish, aqua or deep blue, depending on the depth of the water and amount
of impurities. After heavy rains, many springs are milky, murky, or muddy
because the sediment has not settled due to the amount of water and the speed at
which it is flowing.
Springs are not sterile. Permanent spring dwellers are those plants
and animals which require cool (less than 70 degree F.) constant temperature water of
more than usual clarity, and often high oxygen levels. Among these are water
snails, amphipods, isopods crawfish, salamanders, sculpin (a fish) and beaver.
During hot weather, many animals seek relief in the cooler temperature of the
water. River otter, rainbow and brown trout are introduced species which
thrive in springs; several major springs are fish hatcheries and fishing
resorts based on trout. People have used them as permanent water sources,
refrigeration, and watercress farms. The underground streams which feed the
springs are home to several species of rare and protected cave animals, such
as blind, albino fish and crawfish.
No. Missouri has quite a number of salt and mineral springs, which
would be brackish to the taste. Several of these in Jefferson and Ste.
Genevieve counties were used by early settlers to make salt. Others, like
those at Excelsior Springs, Mo., were very popular as medicinal baths during
the 19th and early 20th centuries. One freshwater spring, Welch, was used as
a health resort for lung ailments early in this century, by a Dr. Thomas Diehl.
He encouraged his patients to come take advantage of the good water and cool
cave air--but the venture was never successful.
This old farmer's tale refuses to die. Because the water is
translucent and rather deep, the bottom cannot be seen. Someone weights a
rope with an anvil or other heavy object to sound the bottom,, which is muddy
or sandy, then lets down the rope. One of two things happen. Either the
anvil grounds so softly the person on the end of the rope does not know it and
continues to play out rope to the end, proving it "bottomless" or the anvil
does not touch bottom because of the great pressure of water squirting out a
small hole, just like a fire hose can be used to move heavy objects with its
force. Most springs have an orifice (sometimes clogged with boulders) thru
which the water flows. Beyond this bottom of the pool opening divers with
proper gear can continue to the limits of their air as well as equipment,
stopping only when the passage becomes too small. This diving is most
dangerous and illegal without permisson in most of Missouri's springs because
of the hazard involved. But they have proven that springs are not
- Learn what you can about them.
- Visit them and treat spring basins gently. Most of the biggest and best
are on public land.
- Understand where the water comes from and that "garbage in" on the surface
of the land becomes "garbage out" of the springs. Don't put trash in
sinkholes. Property dispose of chemical, sewage and other waste. Pick up
litter and think twice about dumping stuff on the ground. Become aware of
industrial plans to develop an area without regard to the
- Take pictures and spread the word that freshwater springs are one of our
most valuable resources, in these days of dwindling good water
- Help the environmental agencies (National Park Service, U.S. Forest
Service, Departments of Natural Resources and Conservation) with their charge
to preserve and protect these Ozark jewels.
- And take time to enjoy each one yourself--then pass that joy to a child to
ensure the future of this resource.