Florida's Springs

Where the waters which flow within the large and complex land areas which comprise the Floridian Aquifer broach the land surface and flow out we have a spring or a spring vent. The vents may be inland, as found at the Rainbow River headsprings, or offshore as found at Tarpon Spring in Kings Bay. Springs and their spring runs which emerge in tidal or navigable waters are classed as sovereignty springs and spring runs. Sovereignty springs require more strict protection rules than regular inland springs as prescribed in F.A.C. 18–21.004(6).

In words of the Florida Springs Task Force, May 2006, "Florida's springs are a critical component of Florida's ecosystems and provide important habitat for many plant and wildlife species. The economic impact of springs is critical to our local, regional, and state economies." ... "The major issues impacting springs include population growth, urban sprawl, growing demand for ground water, and introduction of fertilizers, pesticides, and other pollutants into springsheds" ... "It is every Floridian's responsibility to protect Florida's springs". Florida's concentration of 700 freshwater springs is unequalled anywhere on the planet. One spring alone is estimated to generate $22M each year to its local economy.

It is hard to find words to describe these unique Florida treasures: Marjorie Stoneman Douglas said, "Springs are bowls of liquid light", Archie Carr wrote, "Each spring is different from all the others; but in the intensity of its grace and color each is a jewel in which geology and biology have created a masterpiece of natural art."

Today the springs are important both ecologically and economically, for in addition to being the source of many rivers and providing habitat for countless species — from tiny invertebrates to one–ton manatees — the springs support a host of recreation–oriented businesses such as canoe and tube rentals, dive shops, boat tours, and all the auxiliary concessions that attend such activity.

A Summary and Synthesis of the Available Literature on the Effects of Nutrients on Spring Organisms and Systems

A University of Florida report that was funded by the Florida DEP Springs Initiative program, represents a major effort to pull together "what we know" about nutrients and springs. It also identifies information needs.

An Executive Summary from the report is included and
the PDF report can be viewed here: ExecSumm_TOC_SpringsNutrients.pdf

The entire report can be viewed here: UF_SpringsNutrients_Report.pdf
or it can be downloaded from the DEP ftp site: ftp://ftp.dep.state.fl.us/pub/water/Springs.

Additional valued information is contained in the document issued by the Florida Department of Community Affairs in February 2008 as the Springs Protection Implementation Guidebook, to see the complete pdf document click here.
The document can also be downloaded from http://www.dca.state.fl.us/fdcp/DCP/springs/Files/springsimplementationguidebook.pdf.

Influences upon our springs

We can now begin to address the many influences affecting the quality of water actually emerging from a spring.

The predominance of limestone beneath the surface is responsible for the karst topography so prevalent in the state. The limestone is eaten away by a weak carbonic acid formed by carbon dioxide in rainwater, leaving pits and holes in the rock. Karst landscapes are marked by sinkholes, cavern formations, and springs. The springs result where pressure forces water being stored in underground cavities in the lime rock upward to natural openings at the surface. The porous karst aquifer of Florida is distinguishable from karst systems in more northern states. Because Florida's karst is so penetrable, water seeps through a micropore system and conduits to feed the aquifer, and thus the springs. This realization is changing the way that springs systems are regarded and has critical implications for land use in areas previously thought not to be closely connected to the springs.

Proof of the economic contribution of springs parks is evidenced by a study commissioned by the Florida Department of Environmental Protection. Scrutinizing Ichetucknee, Wakulla, Homosassa, and Blue Springs, researchers found that each park generated an average of $17 million in sales annually for their respective counties, with individuals spending an average of $45 per day during a visit to the springs on lodging, admission, food, and shopping. Just as important as their aid to the economy is the springs contribution to the natural water supply system that supports the state's ever growing population.

Rain falling to the ground even hundreds of miles away from a spring may itself hold contaminants collected from thousands of miles away in the atmosphere, from industrial effluents vented into the atmosphere, or from volcanic ash or desert dust cast there by a natural event, major storm system, or a catastrophic accident, as occurred many years ago as at Chernobyl in the Ukraine. As that rain falls to the ground over the land areas covering the aquifer, additional contaminants are collected from fertilizers, pesticides, human and animal excrement, products of fuel combustion and engine wear in the vehicles we drive, the airplanes we fly in, the power stations that produce the electricity we use, from agricultural, industrial and mining effluents, to name some. Even as those rain waters seep through soils and rocks to join with the aquifer waters, additional contaminants are taken up in the form of nitrates, phosphorous, dissolved calcium and mineral elements, albeit, some contaminants may be filtered out or taken up by plants that need them for their growth.

In times of drought, and when heavy withdrawals of waters are made from the aquifer for domestic and other purposes, water levels in the aquifer drop such that salty waters from the sea and underneath the aquifer may infuse into the aquifer to further contaminate the fresher waters already there. The fresher waters in the aquifer lay over the denser saltier waters. With over pumping, especially in times of drought, the layer of fresher waters is diminished even to allow the saltier waters to issue from the springs, as is happening in Kings Bay in 2007.

Scientists confirm, as we might deduce, that the more populations occupy the land, especially in areas which contribute water in the spring recharge areas, the greater will be the adverse impact upon water quality emerging from the springs. Note that down stream from springs, rivers may form and where half of the water volume in that flow comes from a spring system it is known as a "spring run". The three southern most coastal rivers of Citrus County are in effect sovereignty spring runs.

Of course, there is a price to pay for poor water quality in our spring runs.

Springs Ecology

What we can observe with our eyes is a good indication of what comprises the ecology of a spring system. Fish such a gar, bluegill, bass, sheepshead, tarpon and snook are signs that water quality is sufficient to attract them. That you can see them at all in clearer waters is encouraging. The presence of birds that feed on fish such as osprey, bald eagle, pelican, anhinga, cormorant, egrets and herons – blue, white, snowy white, and little blue, are signs of ecological health when you see them in the air or in the water. The same applies to sighting of alligators, turtles and otters. The fact that manatee choose to winter in a spring run tells us that they find food, warmth and comfort among submersed aquatic vegetation.

One has to get into the water to appreciate the many other species which abound there including crayfish, fresh water shrimp, snails and mussels.

That such wildlife can be seen means that habitat is there to support them. Submersed plants give them shelter from prey as well as habitat for the multitude of other animals and organisms which they need to eat to grow.

Besides observing the waters it is important to consider the land area adjacent to a spring system since this too is part of the ecosystem with its variety of plant habitat attracted to the water for butterflies, cardinals, finches, humming birds, frogs, sirens, salamanders, dragon flies and mayflies, for example. Spring protection zones and buffer areas of natural vegetation are prescribed measures to protect our springs. Such measure also apply to land sinks which drain into the aquifer to minimize artificial accretion, erosion and sedimentation.

On the contrary, when we see wildlife less often or a species is no longer seen, we can begin to conclude that somehow the ecological balance has been disturbed. When waters are no longer clear enough to see the fish, instead algae, diatoms or chlorophyll cloud the water. Some algae are toxic to fish so that they go elsewhere, some algae over run native plants to destroy habitat of the animals and organisms they need as food. The slower stream velocity of water issuing from springs has an important effect upon the formation of algae in the spring run. As the fish move away so do the birds and mammals which feed upon them. We see them less as the result and know that something is wrong. As native submersed plant species are over run by algae they become replaced by invasive species which affect the water and other plant life differently than the native species. Sometimes this imbalance can point to a change in salinity or intrusion of saltier water. Sometimes it follows man's interference to attempt to control a species seen to be harmful, such as hydrilla or water hyacinth. Eliminating a species leaves space to be occupied by a competing species. Herbicides and algaecides applied to water bodies kill bacteria vital to the ecosystem health.

Often blame is aimed at a particular nutrient concentration in the water. It is reported that since the advent of urban dwellings and agriculture in springsheds nitrate and phosphorous concentrations have increased nine times over. However, the real damage is done by simply destroying the habitat by building on it. Over the past ten years some 100,000 single family detached homes have been built in Florida every year. Floridians used in the year 2000, approximately 5 billion gallons every day; as to public supply – 43%, agriculture – 39%, commercial – 8%, recreation – 5%, with 60% of ground water taken from the Floridian Aquifer System which is the source of most of the springs. Note that the 5 billion gallons a day excludes that amount taken via private wells which are not monitored.

The animal and plant communities supported by springs are highly vulnerable to the effects of pollution, human disturbance, and over consumption of ground water.

Factors Affecting Spring Water Quality

Because of the recharge process from rainfall, especially in the local recharge areas, the condition of spring systems is directly influenced by human activities and land uses within the springshed. Where there is little sand or clay covering the limestone karst underneath it is easy for pollutants such as excess nutrients (nitrates, phosphorous and dissolved calcium), heavy metals, oil, petroleum by products and harmful bacteria to seep down into the aquifer. Septic systems, untreated storm water run off and excess fertilizer and pesticides spread on the ground also pollute the aquifer.

From there we draw our drinking water.

Factors Affecting Spring Water Flow

Of the average 53 inches of rain falling on Florida each year less than 25% replenishes the aquifer, say, 13 inches. In 2006, the recorded Florida rainfall was only some 38 inches, allowing less to replenish the aquifer than was drawn from it, by all means.

As with water quality, the volume of spring flow is vulnerable to the effects of activities that occur within the springsheds. Periods of drought, as we have experienced locally since 1999, major development, mining within a springshed or excessive water withdrawals from supply wells can reduce or even stop a spring flow. When some developments increase impervious surfaces, not only is water prevented from direct drainage to recharge the aquifer, the run off collects nutrients and pollutants before allowing recharge of the aquifer – with pollutants included.

It is within this context that we must assess the recent reporting of 75% of the spring vents in the south area of Kings Bay being closed, when having once been in operation within living memory.

A 2006 report of the Florida Springs Task Force includes the following:

"A key challenge of the future is the protection of spring flow of all springs. This is dependent upon the conservative use of water by residential, agricultural, and commercial users in Florida. The protection of spring flow requires the implementation of management and conservative practices that reduce ground water withdrawals to the lowest possible level. If ground water levels are maintained, then spring flows will also be maintained."

Factors Affecting Springs Ecology

The essence of a biological ecosystem is that the constituent parts of the system interact with each other; change one part and the other parts are also changed. When human actions impinge adversely upon a system, biological populations change, leading to a degraded or imbalanced biological community. Pollution–sensitive species disappear, food webs are disrupted, diversity of species decrease, and undesirable nuisance species are able to dominate the community. This exactly describes the current observable situation of the Crystal River/Kings Bay springs run.

Changing land uses within a spring recharge area can produce a change in the type of plants growing at the springs. Mammals such as the manatee can be affected as their food sources change.

Nuisance algal mats and species of exotic plants such as Hydrilla and Milfoil have become increasingly common in springs and spring runs. Thriving on excess nutrients with space to expand, these exotic plants have grown out of control to replace native aquatic vegetation previously relied upon by fish and other creatures.

Benthic macroinvertibrates, such as crayfish and snails, are affected by plant overgrowth, decreased dissolved oxygen, changes in food quality and contamination by chemical compound residues.

Many animals depend upon water flowing from springs. Aquifer withdrawals for domestic or public water supplies can lead to reduced spring flow, threatening the likes of the Manatee and bass which depend upon the spring flows as thermal refuge.