a comprehensive educational resource for understanding Florida springs.
- Understand the Water Cycle
- Define the term Aquifer and understand how it relates to springs
- Understand how layers of the Floridan aquifer system relate to aquifer recharge
- Understand how spring magnitudes are defined
- Define the term karst and identify various karst features across Florida’s landscape
- Understand the trophic structure of a healthy spring system
- Identify the material composition and time period of deposition of what is now known as Florida
- Identify the time period when Florida emerged from the sea and began the process of karstification
- Understand how the Ice Age contributed to springs formation
- Recognize the role of modern tourism in Florida’s springs
- Identify the pioneer studies of Florida’s springgs and their leaders/organizations
- Identify and understand the threats to Florida’s springs
- Understand how springs are managed in Florida
The Water Cycle
To understand Florida’s springs and their importance as natural resources, we must first understand the water cycle and aquifer that sustains them.
Contrary to popular belief, Florida’s springs are not the source of freshwater; they are but one step on water’s long journey from the atmosphere, to the land surface, into the ground through what is known as the Floridan Aquifer, and finally back to the land surface completing the cycle. Learn about the water cycle and the flow of water through the aquifer to gain a better understanding of the source of Florida’s springs. Also, learn more about how humans impact the quality and quantity of groundwater in the aquifer that ultimately discharges through the springs and water supply wells.
Rainfall is a function of various atmospheric and physical factors, including humidity, temperature, and gravity. Relative humidity is a measurement of the amount of water the air can hold at a given temperature. Water vapor measured as humidity condenses as droplets at lower temperatures in the atmosphere. As the tiny water droplets within a cloud merge together into larger, heavier drops, they eventually overwhelm the relative level of atmospheric humidity that keeps them airborne. Scientists have recently determined that once these drops reach a diameter of twenty millimeters, rain will begin to fall. On average about 150 billion gallons per day of rain falls in Florida, with more summer rain than any other state in the nation.
Evaporation and Condensation
Water’s journey to the atmosphere begins with a process called evaporation whereby water stored in lakes, rivers, and the ocean is converted into water vapor by the heat of the sun. The sun’s heat also warms the saturated air, moving it upward through the process of convection. When this warmer, wetter air comes into contact with cooler, higher atmospheric air, it eventually condenses into tiny liquid water droplets. Collectively, these tiny droplets are called clouds.
In addition to evaporation, a significant percentage of the water on the earth is released into the atmosphere by trees and plants in a process called transpiration. In order to facilitate photosynthesis, plants absorb liquid water from the soil through their roots, a process that can also clean water by filtering out nutrients and pollution. They then transpire this vaporized water back into the atmosphere through their leaves and stems. On average about 70 percent of rainfall in Florida returns to the atmosphere as water vapor through the combined process called evapotranspiration.
Rainfall that is not absorbed directly into the soil, through the roots and leaves of plants, or accumulated into existing bodies of water such as lakes or rivers is called surface or stormwater runoff. In areas where the underlying geologic formation is impervious to water, as in the case of clay, runoff is a natural process, directing water over land, into lakes, rivers, wetlands, and the ocean.
In Florida, where loose sandy soils and porous limestone bedrock are common, rainfall that reaches the surface of the earth often soaks directly into the ground. Water that percolates downwards through the tiny spaces between rocks and soil particles, and within the “Swiss cheese” structure of the limestone is called recharge. The water eventually saturates the underlying limestone in much the same way water fills the tiny holes of a sponge. Rainfall and surface water that recharges the groundwater replenishes Florida’s aquifers and is the source of the water flowing from our springs.
The Floridan Aquifer
Aquifers are natural underground reservoirs where water is stored. They fill up from rainwater that percolates down through sand and soil. The water contained in an aquifer is called groundwater. The source of much of Florida’s drinking water and the crystal clear water bubbling up in artesian springs is the Floridan Aquifer, nature’s underground water storage system. But to understand the Floridan Aquifer, we must first understand what an aquifer is and why it’s referred to as “the lifeblood of springs”.
Spaces in the rock, sand, or gravel hold water in storage until it naturally flows out of the ground at a spring or is pumped out of the ground through a well. Since the majority of water extracted for human use in Florida (about 90%) comes from the Floridan aquifer, it is important to understand how we can conserve and protect this valuable resource.
The largest aquifer in the southeastern U.S. is the Floridan Aquifer System, approximately 100,000 square miles in extent and underlying all of Florida and portions of Alabama, Georgia and South Carolina (see map below). Though the Floridan Aquifer is large, it isn’t the largest aquifer in the world. It is, however, one of the most productive aquifers in the world! It is estimated that there are over a trillion gallons of water stored in the Floridan Aquifer.
Some caves inside the Floridan Aquifer are so large that cave divers are able to access and travel through them for many miles underground. The above picture shows a cathedral sized room that could easily hold an airplane! The Floridan Aquifer consists of thousands of feet of carbonate stone that is penetrated by a vast web of interconnected conduits, caves, and cracks that store and transfer water underneath our feet.
There are multiple aquifer systems utilized for water supply in Florida. In addition to the Floridan Aquifer, these include the Sand and Gravel Aquifer of Panhandle Florida, the Biscayne Aquifer of South Florida, the Anastasia Aquifer of Florida’s east coast, the Intermediate Aquifer of Southwest Florida, and various smaller and unnamed geological formations that may be surficial or intermediate in depth. The aquifer systems in Florida are complex, with many layers of shell, sand, gravel, and rock all functioning a little bit differently. These images show a simplified model of Florida’s aquifer system, focusing on two major groundwater systems: The Surficial Aquifer System and The Floridan Aquifer System. A surficial aquifer generally exists wherever impermeable clays or rock are near the ground surface. In these areas the Floridan Aquifer is said to be confined. Where the limestone aquifer is overlain just by permeable sand, the Floridan Aquifer is described as unconfined.
The rocks of the Floridan Aquifer System are classified as either limestone or dolostone. Some areas of rock are thicker than others and form various layers in the aquifer. Over much of its extent the Floridan Aquifer is a single contiguous mass of permeable rock with no separation into different layers. In some places, the Floridan Aquifer System is made up of three levels, commonly referred to as the Upper Floridan Aquifer, the Intermediate Confining Layer, and the Lower Floridan Aquifer. In these areas, water movement between the Upper and Lower Floridan Aquifers is somewhat retarded.
Cross Sectional View of Florida's Aquifer System
The Surficial Aquifer supplies freshwater to areas of Florida where water from a deeper aquifer is not easily accessible, or is salty. The Surficial Aquifer consists mostly of unconsolidated sand and shell, and ranges from approximately 50 to 400 feet thick. Regional sections of the Surficial Aquifer supply freshwater to large municipalities (such as the Sand and Gravel Aquifer in the panhandle and the Biscayne Aquifer in south Florida). Water enters the Surficial Aquifer as rainfall and either evaporates, discharges into streams, or percolates down into the Floridan Aquifer as recharge.
A confining layer is a layer of sediment or rock that has low or no permeability and does not allow water from the surface to easily percolate downward. An unconfined aquifer is an aquifer where there is no confining layer present, allowing water from the surface to move freely into the aquifer. In this model, the Upper Confining Unit has been separated into areas where the confining layer is thick (more than 100 feet), where the layer is thin (less than 100 feet), and where the layer is completely absent. In areas where the confining unit is absent, the aquifer will readily recharge with rainwater.
The Floridan Aquifer is comprised mostly of a deep series of carbonate rock formations, named (youngest to oldest) Suwannee Limestone, Ocala Limestone, Avon Park Formation, and Oldsmar Formation. The Floridan Aquifer is the primary source of fresh groundwater for Florida’s 1,000+ artesian springs and is used by more than 11 million Floridians. The Floridan Aquifer ranges from 250 feet thick in Georgia, to around 3,000 feet thick in South Florida. The Floridan Aquifer may be confined or unconfined, and at times may be in direct contact with the Surficial Aquifer.
As we’ve learned, the source of our drinking water and the crystal clear water in springs is the same – namely the Floridan Aquifer, nature’s underground water storage system. We learned about the process by which our aquifer is recharged in Chapter 1: The Journey of Water. The natural acidity in the rain dissolves Florida’s soluble limerock as it percolates down from the land surface, forming cracks, holes, and dents, some of which, eventually become underground caverns and rivers. These underground rivers find sinkholes connecting to the land surface where the groundwater flows out and forms a spring. Read below to learn more about how springs are formed.
Water begins its journey underground to the aquifer by a process known as recharge whereby rainfall seeps underground to infiltrate the limestone below. The overall land surface area where water seeps underground and contributes rainwater to a specific spring is called a spring’s recharge basin. About 25 million acres of North and Central Florida recharges the freshwater portion of the Floridan Aquifer and all of that area is a recharge basin for Florida’s 1,000+ artesian springs.
Percolation is the physical process by which rainwater falling within a given recharge basin slowly travels underground through the tiny spaces between rocks and soil particles. Florida’s unconsolidated, sandy soils as well as the porous nature of the limestone aquifer itself provide the ideal conditions for unrestricted percolation. Yet, depending on the type of soil and the depth of the limestone aquifer, some areas allow water to percolate water underground faster than others, resulting in different recharge rates. Areas of high recharge occur in only 15 percent of the state, mostly in the sandy highlands of west and west-central Florida.
Speleogenesis is a big word that describes the formation of caves. In Florida, speleogenesis occurs underground through a simple chemical reaction. As rainwater falls through the atmosphere and percolates through the soil, it combines with carbon dioxide in the air and decaying vegetation to form a mild carbonic acid that slowly dissolves the limestone, enlarging small cracks and pores. Over thousands of years, these small pores and cracks expand to become underground caves and caverns. Collectively, these interconnected caves are the pipes through which groundwater flows within the aquifer to the springs.
Gravity is the major force in groundwater movement in the aquifer. Under natural conditions, groundwater moves “downhill” until it reaches the land surface at a spring or through a seep in a riverbed, lake or wetland. The speed with which water flows through the aquifer is also dependent upon the porosity and permeability of the limestone. In other words, water flows more quickly if the spaces or holes in the limestone are larger and if these spaces are closely connected to allow water to flow through.
Sinkholes are depressions in the land caused by dissolution of the limestone near the surface or the collapse of an underground cave. Once these “windows” to the aquifer are open, they may provide direct access to the conduits through which water flows from the recharge basin to the springs themselves. As a result, they are one of the most common points of entry for cave divers seeking to explore and study the underground aquifer.
Springs form where groundwater is forced up and onto the surface through openings in the ground. This is caused by the differences in the slope or “hydraulic gradient” in the aquifer. As rain falls and percolates underground, it exerts pressure on the water already in the aquifer, forcing some to the surface through natural openings. The highest concentration of springs in Florida lies in the north-central part of the state where the aquifer is least confined.
The volume of water flowing from a spring is dependent upon a variety of factors: the water pressure in the aquifer beneath it, the number of caves leading to the spring vent or opening, and the size of the vent itself. Springs are classified or categorized based on the amount water discharge. Florida’s largest springs, for example, Wakulla and Silver Springs, discharge around 65 million gallons of water a day – the equivalent of about 1.3 million bathtubs full! Florida’s springs are the largest by volume in the world, giving birth to and supporting entire river ecosystems like the Suwannee and the Santa Fe. Collectively, Florida’s springs historically discharges over 10 billion gallons of fresh groundwater each day.
Florida’s 1,000 + freshwater springs are scaled and categorized by the average amount of water that they discharge. These categories are also known as magnitudes. Florida’s springs can range anywhere from large first magnitude springs to small eighth magnitude springs!
>65 million gallons/day
That’s more than 100 cubic feet/second! A few examples of 1st magnitude springs are Wakulla Spring, Silver Spring, Troy Spring, and Manatee Spring.
6.5-65 million gallons/day
That’s between 10 – 100 cubic feet/second! A few examples of 2nd magnitude springs are Gilchrist Blue Spring, Wekiva Spring, Ichetucknee Head Spring, and Salt Spring.
0.65-6.5 million gallons/day
That’s between 1 – 10 cubic feet/second! A few examples of 2nd magnitude springs are Peacock Springs, Convict Springs, Ruth Spring, and Johnson Spring.
<0.65 million gallons/day
That’s less than 1 cubic foot/second! Many springs that are 4th-8th magnitude have been given generic names (such as Gil928972) that indicate their county (Gilchrist County, Florida).
Karst Features & Florida Hydrogeology
The geology in Florida consists of limestone formations known as karst terrain. Rainwater is naturally slightly acidic, dissolving Florida’s soluble limestone as it percolates through the surface. Cracks, holes, and dents eventually become underground caverns and rivers, storing Florida’s groundwater and accounting for one of the most productive aquifers in the world. Below are 6 of the most commonly found karst features in Florida.
Artesian springs make up the majority of Florida’s 1,000+ freshwater springs. Artesian springs are areas where pressure in the aquifer causes groundwater to discharge from a karst opening in the land surface.
Caves are formed when water dissolves karst. Most of Florida’s cave systems are underwater but some caves are dry. You can experience Florida’s dry caverns through a guided tour at Florida Caverns State Park. Photo by Florida State Parks.
River Rises & Sinks
A river sink, also known as a swallet, is an area where surface water goes directly underground into the aquifer. The area where it emerges again is a feature known as a river rise.
Sinkholes are areas of karst that have been dissolved by water over time causing the ground surface to collapse. Some sinkholes open into conduits in the Floridan Aquifer. Photo by Florida State Parks.
A karst window is an area where a cave has collapsed and exposed a segment of groundwater that is flowing through the aquifer. As karst windows provide direct access to the aquifer, contaminants from surface water runoff will enter the aquifer directly from here.
A polje is a large, flat basin formed by the coalescence of many sinkholes. An example, shown here, is Paynes Prairie in Gainesville. This polje is connected to the Alachua sink, a sinkhole. At times of heavy rainfall and high aquifer levels, the prairie looks more like a lake. Photo by Florida State Parks.
For tens of thousands of years, Florida’s springs have been hotspots of biological diversity. Based on fossils discovered during the past century, we know that the spring ecosystem once provided water, food, and habitat for many of North America’s most spectacular animals including the mastodon, the saber-toothed tiger and the giant sloth.
Today, what makes springs remarkable is that they are one of the only natural areas in the state that you can encounter so many of Florida’s resident plants and animals in one geographic area. A single visit to a spring can reveal species like the American alligator, river otter, and limpkin. Beneath the surface, underwater natives like the loggerhead musk turtle, manatee, and Florida gar! At certain springs, many of these species can be seen right from the nature trail along the spring run.
Clean, clear water flowing from the aquifer at a constant temperature is the essential ingredient that supports the variety of life found in and around a spring. This chapter will give you an overview of the flora and fauna you can expect to see in a Florida spring and will also take us deeper into spring ecosystems explaining how these plants and animals rely on clean water and one another to thrive.
Springs biology is the in-depth study of primary producers (aquatic plants, algae, and mosses), and consumer groups including invertebrates, fish, reptiles, amphibians, birds and mammals that inhabit Florida’s freshwater springs. The primary producers of Florida springs include various groups of algae (diatoms, filamentous algae and macroalgae like chara), true mosses, and submerged and emergent vascular aquatic vegetation.
Drawing of a great soft-shelled tortoise by famous 18th century explorer and naturalist, William Bartram.
Springs Flora & Fauna
A Deeper Look: Springs Ecology
There are many different types of organisms inhabiting Florida’s springs such as plants, insects, and fish. Each of these organisms are dependent on each other in different ways! For example, snails depend on algae for food while fish depend on vegetation for habitat structure. All these different plants and animals interacting with each other, as well as their physical environment (rocks, soil, water, etc.), make up an ecosystem. Ecosystems are often characterized by specific roles played by each living and non-living thing – each member of the ecosystem has the potential to directly affect the ability of another to survive. Commonly one organism will depend on other organisms as their source of food. The organisms in an ecosystem are often categorized by degrees of consumption or trophic levels. Each higher trophic level represents a step further removed from the earth’s original energy source, the sun.
The most basic trophic level is occupied plants and other photosynthetic organisms that are called primary producers. Primary producers capture the energy from the sun’s rays to make their own food in the form of sugars and include vascular plants and algae. By converting energy from sunlight into chemical energy/food, plants and algae “produce” usable energy for the rest of the ecosystem. The next step up from producers are the primary consumers or herbivores. These organisms feed solely on primary producers to get their energy. Next up are secondary consumers, tertiary consumers, and ultimately the top consumers, which prey on other consumers of equal or lower levels. Springs have what scientists call a “high level of primary production”, meaning these hard-working ecosystems are able to support an abundant and diverse array of trophic levels. See how the organisms in a spring ecosystem rely on one another in the food web graphic below!
Springs Food Web
The food web to the right demonstrates how energy flows between organisms in a healthy spring ecosystem. The arrows point from the source of energy or “food source” to the next higher-level consumer. Notice how each organism depends upon others to adjust populations of their food source. If one or more organisms are artificially removed by over harvesting, that will allow that organism’s prey which in turn may eliminate the next lower trophic level’s population. The resulting populations of every other organism in the ecosystem may be affected as a result. This process which can operate up or down the foodchain is termed a trophic cascade. Spring ecologists are observing negative changes in water quality that are causing an over-abundance of filamentous algae which is not very palatable for native spring consumers such as aquatic insect larvae. With the loss of submerged aquatic vegetation (SAV), other species are negatively impacted due to loss of habitat structure and food source – SAV and the epiphytic algae that grows on its surface. When you look at the springs food web, see if you can identify which species are impacted the most by the loss of SAV.
Springs have been an important part of Florida’s environment for thousands of years. Use the arrows to explore the Springs History Timeline.
Spring History Timeline
The oldest rocks exposed at the surface in Florida are limestones and dolostones that were deposited in a shallow, warm sea during the Middle Eocene age. These rocks consist of the remains of marine organisms (foraminifera, mollusks, echinoids) that died and settled to the bottom of the sea. These limestones comprise part of the Floridan aquifer system, one of the most productive aquifers in the world and the source for most of Florida’s spring water.
Main Image: Remains of marine organisms (foraminifera, mollusks, echinoids) that died and settled to the bottom of the sea 40 million years ago. © FDEP – Harley Means
30 Million Years Ago
In response to a global sea-level decline, the Florida Platform emerges from the sea. While the Florida Platform is exposed above sea-level, the slow but steady process of karstification by acidic rainfall forms the void spaces in the limestone, some of which would later become Florida’s springs. Fossil remains of the first land mammals that found their way into Florida during this time can be found in sinkhole deposits today.
2.6 Million Years Ago
The beginning of the Pleistocene epoch otherwise known as the ice age. Massive continental glaciers advance and retreat causing sea-levels to fluctuate widely. Florida is undergoing further karstification and the Floridan Aquifer System repeatedly fills and drains with saltwater from the oceans and fresh water from rain. Many of our springs are formed during this time as sinkholes and as water levels in fluctuate, some begin to discharge water becoming springs.
Humans arrive in Florida
Humans arrive in Florida in search of fresh water, game and fish, and chert resources, all of which are commonly found at springs! Evidence of their arrival in the form of bone and chert tools and the butchered remains of Pleistocene animals, is commonly found at Florida’s springs. Some of the earliest known human artifacts to date have come from Silver Springs, Wakulla Springs, Warm Mineral Spring, and the spring-fed Wacissa/Aucilla River, among others.
Florida’s First Spanish Explorer
Juan Ponce de León landed along Florida’s east coast near St. Augustine, naming the new land “La Florida” (“Place of Flowers”). One goal of his exploration in the region was to locate Bimini, whose legendary spring, referred to by Native Americans as the “fountain of youth”, was believed to make older people young again. His interaction with the Calusa Indians in 1521 ended badly when Juan was shot with an arrow. He would later die of this wound in Cuba.
Naturalist William Bartram
William Bartram, a naturalist from Pennsylvania, comes to Florida. During his visit he explores several Florida’s springs, including Manatee and Volusia Blue Spring, and makes some of the first written accounts about these immense upwellings of crystal clear groundwater.
Fossilized Mastodon Recovered from Wakulla Springs
Fossil bones of a mastodon are recovered from Wakulla Spring. The fossils were later articulated and the skeleton is currently on display at the R.A. Gray Building in the Museum of Florida History in Tallahassee. 1930s- Glass bottom boats became widely used to enhance the Silver Springs attraction. Herpetologist Ross Allen brings alligator, snake, and turtle shows to Silver Springs as part of the “Ross Allen’s Reptile Institute”.
Edward Ball Purchases Wakulla Springs
Edward Ball, brother-in-law of chemical tycoon Alfred DuPont, purchases Wakulla Springs. Construction of a Spanish-style twenty-seven room lodge at Wakulla Springs begins in order to create an exclusive resort. The Silver Springs attraction is enhanced by the addition of a Seminole Indian Village.
Tarzan and Monkeys at Silver Springs
Colonel Tooey imports rhesus macaque monkeys to an island in the middle of the Silver River. Colonies of their descendants populate forests around the Silver Springs attraction. Johnny Weissmuller stars in Tarzan Finds a Son, which is filmed at Silver Springs.
First Study of Florida Springs by FGS/ USGS
The first comprehensive study of Florida’s springs was titled “The Springs of Florida” published by the Florida Geological Survey and US Geological Survey. This 196 page volume describes over one hundred springs, their location, flow, and water chemistry data.
Mr. Peabody and Mermaid at Weeki Wachee Spring
Mr. Peabody and the Mermaid is a 1948 fantasy film starring William Powell and Ann Blyth in the title roles. Irene Hervey played Mr. Peabody’s wife. The film was based on the 1945 novel Peabody’s Mermaid by Guy and Constance Jones. Sequences were shot at the Weeki Wachee Springs in Florida.
Manatee Springs State Park Established
Manatee Springs is the first large spring acquired as a Florida State Park Service. Eighteen additional state parks will be created, with Gilchrist Blue Spring State Park established in 2018.
Scuba Comes to Florida Springs
An unnamed National Speleological Society diver is believed to be the first person to use SCUBA in a Florida spring, diving into the Ichetucknee Blue Hole (Jug Spring) to retrieve a pair of prehistoric alligator skulls for a biology professor at the University of Florida. In 1953, Charles McNabb, Bill Ray and Frank DenBlykker make the first documented exploratory cave dives in Florida using SCUBA, in the Main (Mammoth Spring) vent at Silver Springs.
Gary Cooper in Distant Drums at Silver Spring
Gary Cooper and Mari Aldon star in Distant Drums, filmed at Silver Springs. The film was set in the everglades in the 1840s during the Second Seminole War. The Creature from the Black Lagoon, starring a gruesome gill man played by Ricou Browning is filmed on location at Wakulla Springs, Silver Springs, and Green Cove Springs. It was one of the first films filmed in 3-D.
A Look into the Past
Long before modern theme parks, Florida’s springs were one of the original tourist attractions drawing people from around the country to Florida to experience their clear, cool waters. Some of the first experiments in underwater photography took place in Florida’s springs. The Florida State Archives include many wonderful historic spring photos. We’ve highlighted some of our favorites here. Hover over the photos for their description.
Springs Then & Now
Before Florida’s population began to skyrocket in the 1960’s and the mass development, deforestation, and farming of land came as a result, Florida’s springs looked different than the springs we see today. Most people who see the springs for the first time today are impressed by their beauty, but someone who experienced them years ago might be struck by how they’ve changed. The following collection of images from Florida Nature Photographer John Moran offer a glimpse into what springs have looked like in the past and what they look like in recent times.
Threats to Florida's Springs
In this section we will learn about some of the problems facing the Floridan Aquifer and its springs. Impacts to our groundwater fall into two main categories – water quality and water quantity.
Increases in population, development, and intensive agriculture in Florida have resulted in increased groundwater withdrawals. These withdrawals affect water quantity in the Floridan Aquifer, which can have a negative impact on spring flows. Water quality in the aquifer and springs can be impacted by substances like nitrogen from wastewater, livestock, and fertilizers. Keep reading to learn more about impacts to Florida’s groundwater.
In 2015, an estimated were withdrawn from the Floridan Aquifer.
Every day, more than 2.3 billion gallons of groundwater is pumped from the Floridan Aquifer. The result is that we are depleting groundwater resources faster than they can be replenished by rainfall. Excess groundwater use has a direct, negative impact on the biological communities of springs, as well as leading to the collapse of the underground geologic structures, the formation of sinkholes, and the drying up of wells. We can do our part by reducing our water use every chance we get.
Every year, many millions of tons of fertilizers and pesticides are applied to fields to improve crop yields, kill insects and prevent disease. Unfortunately, some of these pesticides and fertilizers applied in karstic areas leach directly underground or enter the aquifer through sinkholes and surface rivers. Like chemicals used in residential landscaping, agricultural fertilizers and pesticides can pollute our drinking water and harm sensitive biological communities at the springs. Row-crop agriculture is also Florida’s second largest consumer of groundwater.
Each year, nitrates from thousands of tons of animal waste leach into Florida’s groundwater. Concentrated waste runoff from farm buildings, improper waste discharge, storage facility leaks, and excessive land application of waste products are all ways that intensive livestock farming can pose a threat to ground and surface water. In addition to these, poor site selection, farm mismanagement, lack of regulation, and absence of well monitoring can all lead to contaminated groundwater.
Human waste has elevated levels of nutrients as well as pharmaceutical contaminants such as antibiotics, hormones, and other trace organic compounds. These contaminants can find their way into our surface water and groundwater. Onsite sewage treatment and disposal systems, commonly referred to as septic systems, are used by up to 30 percent of Florida’s population. These on-site sewage treatment and disposal systems become very problematic for springs and drinking water when they are not installed properly, are not well maintained, or exceed the treatment capacity of regional soils.
The quest for the perfect lawn has negative impacts on the environment and our water. Many homeowners use varieties of turf grass that require large amounts of irrigation, fertilizer, and pesticides. Irrigation depletes the aquifer and fertilizers and pesticides may enter the aquifer in two ways: by being carried by rainfall and discharging into surface water, or by leaching into the soil and percolating into the groundwater.
Florida’s expanding population has put pressure on the undeveloped places that naturally filter and recharge our springs and drinking water supply. The rapid increase in Florida’s population since the 1950s has led to dramatic changes in land use, transforming rural areas that were once dominated by forests and native grasslands into residential developments, shopping centers, and industrial parks. The increase in pavement, roads, and other impervious surfaces prevent rainwater from percolating into the aquifer and increase the amount of harmful chemical pollutants making their way underground into our water.
Stormwater runoff is rainfall that flows over the ground surface. In developed areas, rainfall hits impervious surfaces (buildings, roads, and parking lots) and cannot penetrate the surface where it lands. The stormwater then picks up pollutants as it travels along the ground surface and eventually discharges into a waterway, or percolates into a pervious surface with the additional pollutants that it picked up on its journey. Stormwater runoff can carry with it pollutants like antifreeze, heavy metals, fertilizers, fecal matter, bacteria, and sediment. These pollutants have the potential to impact both surface water and groundwater quality.
Recreational Land Use
Nitrogen rich fertilizers are applied all across Florida to recreational landscapes like sports fields and golf courses. As an example, golf courses occupy more than two hundred thousand acres of land in Florida. Much of this land is covered with turf grass that is fertilized and treated with pesticides that may leach into the aquifer. Over fifteen hundred golf courses exist in Florida, more than any other state in the country. Golf courses can have a negative impact on Florida’s aquifer by increasing nutrient loads and groundwater withdrawals.
Springs are a multi-million-dollar industry in north Florida. Due to their popularity as recreational locations, some springs are being “loved to death”. During the peak summer months, Ichetucknee Springs State Park’s daily limit of 750 tubers on the upper river can be reached within an hour after the park opens. Tubers and swimmers can unknowingly trample native vegetation and increase turbidity (cloudiness) of the water, uncontrolled foot traffic can cause bank erosion, and human refuse can introduce pollutants and harm wildlife such as turtles and manatees.
Invasive species can cause extensive damage to our waterways by limiting flow, blocking sunlight and nutrients from native plants, and reducing oxygen levels in the water. Invasive plants can limit human activities like boating and fishing because they can clog waterways and even damage boats. Unfortunately, invasive species removal has proven to be complex. Chemical and mechanical control of invasive plant species like hydrilla (Hydrilla verticillata) and water hyacinth (Eichhornia crassipes) are harming some springs and spring runs, often causing negative impacts to spring health.
Water Management Districts (WMD)
Florida springs are managed by five government agencies. The first is the Florida Department of Environmental Protection and the remaining four are the four water management districts that govern the Florida springs region. The five water management districts of Florida are Northwest Florida, Suwannee River, St. Johns River, Southwest Florida, and South Florida Water Management Districts (WMDs). The Florida spring region reaches into parts of four water management districts (Northwest, Suwannee River, St. Johns, and Southwest Florida Water Management District). Each water management district is led by a Governing Board made up of appointees from within their District. These board members are appointed by the Florida Governor and confirmed by the Florida Senate. WMD board members should represent a cross section of interests, including the environment, agriculture, local government, recreation, and business interests.
Water Management District Boards have three primary powers:
- Issue Consumptive Use Permits
- Levy ad-valorem (local) taxes
- Set protective standards (Minimum Flows and Levels) for water resources
in their district.
Learn about how consumptive use permits and Minimum Flows and Levels
determine the protection of springs below.
Water Management District Regions
“Water management districts are the most significant entities in Florida as far as affecting the physical and growth management aspects of the state”
– Estus Whitfield, chief policy advisor to six Florida Governors
Consumptive Use Permitting Explained
A Consumptive (Water) Use Permit is required for any withdrawal of water of over 100,000 gallons per day. These permits allocate a specific amount of water, for a set duration, under specific conditions.
To obtain a Consumptive Water Use permit, an applicant must prove the water use is:
- Reasonable and beneficial.
- Does not interfere with an existing permitted use.
- In the public interest
- In cases of water shortage, governing boards are authorized to reserve water from use, or impose restrictions on existing permits.
Minimum Flows & Levels (MFLs)
Minimum Flows and Levels (MFLs) are defined as the minimum flows or minimum water levels at which further withdrawals would be significantly harmful to the water resources or ecology of the area.
Establishing MFLs is the method provided by Florida law for our water management districts to protect our springs, lakes, wetlands, aquifers, and rivers from significant harm.
Important to know about current MFLs for outstanding Florida springs:
- In theory, MFLs can be used to protect waters from negative impacts from human impacts such as over-pumping and pollution.
- A “recovery or prevention strategy” allows the Board to deny new consumptive use permits or the reserve water from existing permits
- Despite the clear intention of the law, MFLs are currently being set at flows and levels which are not protective of the resource.
- According to research provided by the Florida Springs Institute, MFLs are being proposed which would allow increased pumping in already impacted waters.
Call to Action: Fill Our Water Management District Board Seats!
As we stand, there are an alarming amount of WMD governing board vacancies in the four water management districts that govern the Florida springs region. There are currently zero environmental science or conservation representatives sitting on any four water management district boards. Encourage Governor DeSantis to appoint qualified water management district board members and fill governing board vacancies by calling his office at (850) 717-9337 and leaving a message stating:
1. Water management district boards should not make any decisions, including water use permits, until all of the vacancies are filled, and
2. It’s time to appoint some of the qualified applicants whose resumes sit on his desk – representatives from science and conservation.
Take it a step further by joining or donating to the Florida Springs Council. The Council is a consortium of member organizations from all over the state who are working together to ensure the restoration, preservation, and protection of Florida’s freshwater springs and the Floridan Aquifer through advocacy and legal action. — Updated 01/31/20
Florida Department of Environmental Protection
The Florida Department of Environmental Protection (FDEP), unlike the WMDs, is part of the executive branch of Florida’s government and answers directly to the Governor’s Office. FDEP is run by a Secretary appointed by the Governor and confirmed by the Senate. FDEP’s budget is decided by the Legislature in the General Appropriations Act. FDEP regulates water quality protection and oversees WMD decisions. FDEP’s principal mechanism for monitoring and improving water quality of springs is the Total Maximum Daily Load process and Basin Management Action Plans.
Total Maximum Daily Loads (TMDLs)
A TMDL is a scientific determination of the maximum amount of a given pollutant that a surface water can absorb and still meet the water quality standards that protect human health and aquatic life. Water bodies that do not meet water quality standards are identified as “impaired” for the specific pollutants of concern – nutrients, bacteria, mercury, etc. – and TMDLs must be developed, adopted and implemented to reduce those pollutants and clean up the water body.
The Total Maximum Daily Load program steps:
- Assess the quality of water
- Determine if the water body is impaired
- Establish and adopt, by rule, a TMDL for each impaired water for the pollutants of concern–the ones causing the water quality problems
Basin Management Action Plans (BMAPs)
Basin Management Action Plans is FDEPs “blueprint” for protecting impaired waters by reducing pollutant loadings to meet the allowable loadings established in a Total Maximum Daily Load (TMDL). The plan defines a set of strategies such as permit limits on wastewater facilities, urban and agricultural best management practices, conservation programs, financial assistance and revenue generating activities, etc. – designed to implement the pollutant reductions established by the TMDL. These broad-based plans are developed with local stakeholders – they rely on local input and local commitment – and they are adopted by Secretarial Order to be enforceable. The BMAP process includes the following steps:
Basin Management Action Plans should define and enforce the following:
- Sufficient projects and better management practices capable of reaching the Total Maximum Daily Load target.
- For most waters, the presence of a BMAP prohibits activities which pollute water further
- In 2016, legislation was passed requiring the adoption of BMAP’s for all 30 Outstanding Florida Springs.
- The following additional protections for all Outstanding Florida Springs in priority focus areas.
- No new septic tanks on small lots
- No new conventional wastewater treatment facilities
- New Agriculture operations must adopt best management practices
- Evaluation of BMAPs progress every 5 years
Outstanding Florida Springs
In 2016, Senate Bill 552 created the “Florida Springs and Aquifer Protection Act,” in which the Legislature designated Outstanding Florida Springs (OFS). Senate Bill 552 required that minimum flows or minimum levels (MFLs) be set for all OFS on or before July 1, 2017. Section 373.802(4), Florida Statutes (F.S.), defines “Outstanding Florida Springs” or “OFS” to include all historic first magnitude springs, as determined by the department using the most recent Florida Geological Survey springs bulletin, and the following additional six springs: DeLeon, Peacock, Poe, Rock, Wekiva, and Gemini. OFS do not include submarine springs or river rises. There are 30 OFS springs consisting of 24 historic first magnitude springs and the 6 named additional springs.