Ponce de Leon Springs, a Florida state park.

CLEAR, FRESH WATER POURING FROM BENEATH Florida's rocky terrain has captured human interest for thousands of years. Ancient artifacts found near springs suggest that early Native Americans took advantage of the steady supply of fresh water and settled their villages along spring banks. International interest in Florida's springs erupted in the early 1500s when Spanish explorer, Ponce de Leon, scoured Florida's landscape in search of the "Fountain of Youth." By the twentieth century, "spring houses" had become popular recreation sites offering cool refuge from the scorching Florida sun. Today, Florida's springs continue to attract world-wide interest as millions of tourists and thousands of geologists travel from around the globe to appreciate and enjoy Florida's natural wonders.

Once popular recreation sites, spring houses offered cool refuge from the Florida sun. Springs continue to attract millions of tourists.

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SOME FLORIDA SPRINGS

Releasing over eight billion gallons of freshwater each day, Florida has the most productive spring system in the world. Over 600 springs have been documented and geologists estimate that hundreds more are waiting to be discovered. Each spring is unique, but geologists categorize them according to specific hydrogeologic characteristics such as water flow, temperature, associated aquifer, water composition, and the shape of their opening.

Blue Spring	Cow Spring	Orange Grove Spring	Peacock Spring	Running Spring	Telford Spring	Wakulla Spring	Wakulla Spring

Source: USGS

SPRING FORMATION
Although people have enjoyed Florida's springs for thousands of years, spring development began millions of years ago. Eons of geologic and erosional processes modelled the limestone peninsula into a karstic region that is characterized by a variety of unique geologic features that include freshwater springs, sinkholes, and a poorly developed drainage system.

As a result, surface water enters the water-bearing limestone bedrock and enters the underground aquifer. When the water-table intersects the surface, freshwater flows from natural openings in the ground.

SPRINGS AND THE AQUIFER
Springs are actually the visible feature of an extensive underground aquifer system. Beneath the surface, groundwater continuously travels from areas of recharge, or replenishement. As groundwater accumulates beneath the surface, the water-table rises and the subsurface water-pressure, or the hydrostatic head, increases. Groundwater pushes along the hydraulic gradient toward areas of discharge. Under pressure, groundwater is pushed to the surface through natural openings in the limestone bedrock, creating springs of flowing water.

The amount of water released from a spring depends on hydrologic and geologic factors such as rainfall, permeability of the aquifer, porosity of the limestone, water pressure, subsurface flow, well pumping, shape of the spring vent, and in submarine springs, atmospheric pressure and oceanic tides.

All of Florida's first magnitude springs and many of the smaller springs are associated with the Floridan Aquifer. The amount of water discharged from a Floridan spring pales in comparison to the amount of confined groundwater stored in the aquifer. As a result, Floridan spring flow remains relatively unchanged during periods of drought or heavy rains. Likewise, the water quality and average temperature of Floridan spring water remains generally constant.

In contrast, surficial springs can experience dramatic variations in flow, temperature, and water quality. Groundwater in surficial aquifers is unconfined and continuosly flows from areas of recharge, or replenishment, to sites of discharge to the surface. Therefore, flow rates of surficial springs are affected by periods of drought and heavy rains. Water quality in a surficial spring may also reflect the quality of water leaching into the aquifer.

SUBMARINE SPRINGS
Along the Gulf and Atlantic coasts, submarine Floridan springs release freshwater from beneath the ocean floor. Although they are difficult to detect, fifteen submarine springs were discovered by 1995. If the spring is large enough, it will disturb flat seas by creating a slick, or boil, at the water's surface. Most occur in bays and estuaries along the Gulf coast between Lee and Wakulla counties. At least one has been located on the Atlantic coast 2.5 miles offshore of Crescent Beach.

WATER QUALITY
Generally, the water quality in a spring will reflect the overall conditions of the aquifer. It can be affected by the quality of water replenishing the aquifer and the type of rock the groundwater comes in contact with. The more time groundwater spends in the aquifer, the greater the amount of minerals that are dissolved in it. Spring water may also become brown from tannins. Tannins are from organic matter such as leaves; tannic spring water is not toxic. Tannins get into the springs usually as a result of river water intrusion, or from surface water entering a surficial aquifer through recharge areas and moving quickly through subsurface channels, not having the benefit of filtering through the limestone. Spring water may also contain traces of contaminants that have leached into an aquifer through polluted surface water.

Spring waters are well known for their clarity and freedom from algae. Algae does not flourish, even though there are sufficient nutrients and sunlight penetration into the water, because spring water is fast moving and flows away before algae has time to develop.

Springs are where aquifers meet the surface; looking into springs is looking into aquifers.

GATEWAYS TO UNDERWATER CAVES
Springs are actually the surface openings of an extensive underwater cave system that lies within Florida's limestone bedrock. A result of groundwater erosion, the complex network of subterranean rivers conducts freshwater through the aquifer and to the surface.

The maze of underground water conduits represents a new frontier in exploration; highly skilled cave-divers continue to survey and investigate thousands of feet into underwater caves where they collect data on Florida's water quality, drainage patterns, hydrogeology, and cave biology.

SPRING LIFE
Springs sustain ecosystems that support life of a multitude of organisms, including humans. Above ground, plants and animals living above and below the water depend on the constant supply of clean fresh springwater that feeds hundreds of freshwater habitats in Florida's wetlands, lakes, and rivers. Beneath the surface, aquatic cave creatures called troglobites, live in a lightless underwater environment, relying on consistent water temperature and water quality for survival. Slight changes in water quality or water flow, can annihilate an entire population. Today, over one quarter of all known aquatic troglobite species in Florida are threatened or are of special concern.

PLANTS and PLANT MANAGEMENT in FLORIDA SPRINGS
Of hundreds of native aquatic and wetland plant species in Florida, relatively few are found in the cool, fast-moving waters of springs and spring runs. Among the most common natives found in springs are tape grass and strap-leaf sagittaria.

tape grass	strap-leaf sagittaria	red lugwigia	Florida water cress	muskgrass	lizard's tail

However, non-native, invasive aquatic plants are also present in Florida springs, sometimes infesting them and covering them entirely. The most common invasive plants in our springs include hydrilla, water lettuce, and egeria.

When exotic plants invade our springs, the plants must be controlled. Springs are generally the responsibility of the state, county, and local governments. For information about aquatic plant control in springs, please visit this page on this web site.

HUMAN IMPACT
Changes in a spring's ecosystem will create a chain reaction, jeopardizing thousands of species, including humans, for hundreds of miles. Many of Florida's springs are threatened by urbanization and inadequate management. As Florida's population rises, springs are increasingly threatened by contamination, destruction, and decreased water flow. Go to this page of this web site to learn about over-pumping, bank erosion, pollution, invasive plants and animals, scuba divers, fossil digging and other human impacts in our springs.

SPRINGS AND RECREATION
Federal, state, county and city departments, as well as some private companies, manage and protect hundreds of Florida's freshwater springs for the public to enjoy.

Care is necessary. Minor disturbances in a spring's water supply or ecosystem can have devastating effects on the plants, wildlife, and people that depend upon it. Conservation of these aquatic gems is essential in order to insure their survival for generations to come. If protected and managed properly, springs can provide an assortmant of recreational activities.

Here are some Florida State Parks that feature springs: