Florida—a state whose very name is powerfully evocative of stunning beaches with sugary white sands flanked by sparkling Gulf waters and majestic waves of the Atlantic; graceful towering palms, stylish art deco buildings trimmed in turquoise, coral, and the aptly named seafoam green; thriving groves of oranges and grapefruit and lush botanical settings flanking the deep blue pools of the famed Florida springs. You can almost smell the Coppertone at its very mention, or hear Tarzan with his famous yodel calling to Jane. That’s right, Tarzan, the original Tarzan, whose adventures were filmed during the 1930s and ’40s at Florida’s world-famous Silver Spring, the country’s largest artesian spring. Amid settings of exotic foliage, tropical birds, and unique wildlife, the Florida springs are indeed a natural paradise.
All Is Not Well in Paradise
Florida is not what it was in the days when Johnny Weissmuller and Margaret Sullivan played house in the ersatz African treetops of Silver Springs in the ’30s and ’40s. A hundred years ago, fewer than a million people lived in Florida, but as of December 2014, the state ranked third in US population with more than 19 million people. However, its popularity as a warm retreat for both permanent residents and vacationers, coupled with booming growth and development, brings an unabated demand for food and fiber and water that exerts pressure on every acre of the state. With more residents come more subdivisions, businesses, and expanding amenities, and the recreation and utilities to serve all of them. Bigger farms require more irrigation, and millions of year-round enthusiastic tourists add to the demands. The cascade effects on the Florida springs—the principal aquifer for the entire state—is severe in direct and indirect consequences: pollution and contaminants from septic and agricultural runoff, excessive groundwater withdrawals, and physical damage to the sensitive environments leading to consequences for fish and wildlife.
The environmental problems have prompted a state acquisition of privately owned spring park properties that are suffering. The state now owns at least 17 major springs as part of the state park network, including the Silver Springs, a group of 25 artesian springs that Dr. Robert L. Knight, founder and the executive director of the Howard T. Odum Florida Springs Institute, calls “the crown jewel of Florida.”
Knight offers a condensed timeline of events of land use affecting Florida’s springs, using the iconic Silver Spring as an example: “Years ago Silver Spring discharged 500 million gallons of water per day, enough water for about 5 million people, but two things happened to change the land use affecting the springs and their waters. One was the invention of the electric pump, which could provide irrigation to otherwise worthless lands, and the second was the decline of the citrus groves that were replaced by urban developments.”
Knight notes that Florida is on the same latitude as the Sahara Desert, but because of the “abundance of rainfall of 51-plus inches a year, the peninsula surrounded by ocean gets convective rain events. But in a dry year, the state starts dying, and groundwater pumping from the springs aquifer levees becomes mandatory to supply the needs of 19 million permanent residents and the 90 million tourists who visit us each year.”
Artesian springs are specific freshwater systems, he says, and in Florida are further unique in that they are situated over the ocean. Some, like those in the Jacksonville region, have a mantle of impermeable clay over the limestone so waters for their recharge “must travel miles.”
Knight explains that Florida has huge amounts of underground limestone that is easily dissolved by the slightly acidic rainwater that is absorbed underground. The result of this breakdown is formation known as karst, a geomorphology that he describes as a “a vast network of Swiss cheese rock.” The majority of Florida’s rainwater enters the aquifer system through this rock, and once belowground and under the pressure of the rock, it creates an “overflow.” The overflow is discharged during the spring boil and provides the crucial freshwater that then feeds streams and rivers. However, Knight says, “On average we lose 70% of our rainwater due to evaporation. And about another 15% runs off to make rivers and lakes, with about 6% for aquifer recharge.”
A number of factors including groundwater withdrawal, sediment clogging underground, proximity to the surface of these limestone confining formations, and how much water they are transporting (or not), can have a cascade of unwanted effects.
That Sudden, Sinking Feeling
According to the US Geological Survey bulletin Sinkholes of West-Central Florida, when the limestone dissolves from the acidic rains, forming karst, the cavities that are created range from small holes with crystals (called vugs) to large extensive caves. These karst formations are responsible for the proliferation of springs but also for sinkholes. When a sinkhole forms, the earth covering an area that is basically hollow underneath simply falls away. While these spontaneous “implosions” are often a nuisance and have been the subject of comedy routines, they can be anything but humorous. Sinkholes can cause considerable property and structural damage and can threaten lives if someone is in the wrong place at the wrong time, such as driving on a highway, playing golf, mowing a lawn, or taking a walk on a surface that suddenly falls in.
The USGS bulletin says the link between surface water, groundwater, and sinkholes is significant. Sinkholes are a predominant landform in Florida that is on the increase, and the agency says the frequency of sinkholes “corresponds to the accelerated development of groundwater and land resources.” As more of these sinkholes occur, they can also act as storm drains, introducing runoff and contaminants, causing a rerouting of springs’ water, and bringing in unwanted sediments.
Sinkholes are more prevalent in recharge areas where the water movement is downward; conversely, in discharge areas such as springs where the movement is upward, they are less likely to occur. When the confining unit has collapsed and sinkholes form, the “downward movement of water and sediments of the surficial aquifer system can be greatly accelerated,” according to the USGS.
Because sinkholes can change the entire dynamic of a spring, their potential for developing near springs where the discharge is declining from lowering groundwater levels is a major concern.
Visitors enjoy swimming, boating, and cave diving in the 68–74°F waters, depending on the location, which remain a constant temperature year round consistent with the average aboveground air temperature. Florida’s Warm Mineral Spring on the Gulf Coast near Port Charlotte is the world’s largest warm mineral spring with its 1.5-acre pond and a center depth of nearly 250 feet. Most Florida springs are from 80 to more than 200 feet deep.
According to the US Geological Survey, springs are aquifers that act like a sponge, receiving their water through large, hollow tunnels, and are the surface evidence of a vast underground water resource. The huge amounts of water discharged by springs at the “spring boil” is an indication of the large capacity of the springs to both store and transmit water, and changes in their flow and amount discharged is a red flag to the overall health of these systems.
According to geologists, there are an estimated 900 or more springs in Florida, which makes the state likely to have the highest concentration of freshwater springs anywhere on the globe.
Growing, Growing, Gone?
With the booming growth in Florida and the demand for water to grow food and supply the population, growers and developers are removing more groundwater than ever before to quench their needs, and the springs are Florida’s primary water source. In some cases springs have simply dried up and no longer flow, such as White Springs off the Suwannee River, or their flow has been drastically diminished and large algal mats have formed on their surface, choking off the life underneath.
The biggest culprits for algae growth include excess farm fertilizer runoff, animal manure from dairy and poultry operations, leaching from disposal sprayfields, lawn treatments from homeowner and golf course fertilizing, and faulty septic systems. Nutrients create algae, and some of the algal mats are substantial enough to walk on. Power boating and public trampling of spring shores by visitors are also implicated in the environmental degradation. Native species of aquatic plants can die off, causing habitat-dependent wildlife like otters and turtles to leave.
However, it is the introduction of nitrates that by far causes the most serious consequences, and agriculture is the biggest contributor. Knight describes the effects of irrigation by the center pivot systems, called “traveling irrigation.”
“These have sprung up all over north Florida where we have this groundwater available. Their consumption is 2 billion gallons per day, and this is coming from the same aquifer we drink from. The nitrate contamination from irrigation when much of it is not absorbed and runs off has resulted in historic algal bloom. It is associated with the horrific mortality of manatees, and with red tide.”
Although Knight says that citrus has actually moved out of north Florida, there are other crops, livestock, and new development taking over, but management and control of water has not set a good record. Florida is unique in that water cannot be privately owned. “The water system is held in the public interest, and groups of water management districts, based on the watersheds, are the agencies that have the control.”
He says water districts were giving out agricultural permits without actually knowing how much water was being used, but now, “finally, enough citizens are fighting these permits.”
He continues: “Right now, we’re at the beginning of the revolution and the revelation, especially concerning groundwater withdrawal as we have lots of surface and a low topography.”
Diverse Participants, Same Goals
Examining the health issues of the Florida’s springs is on the radar of several entities including state and local agencies, academia, and advocacy groups who collectively serve as the Water Policy Advisory Council to the Florida Department of Agriculture and Consumer Service (FDACS). They may have different agendas, budgets, and expertise, but all are focused on ensuring the springs are healthy and protected and that they remain viable.
According to Rich Budell, director of the Office of Agricultural Water Policy at the FDACS, the greatest number of springs are located in northern Florida in what he calls the Big Bend area, a region bounded on the south by Interstate 4 between Daytona and Tampa and with the St. Johns River as the eastern boundary. This concentration of springs is an international destination for recreation such as cave diving, a showcase for spectacular cave formations, and a designated preserve for endangered wildlife and native Florida wildlife such as the red wolf, Key deer, alligators, and the Florida manatee. And who could resist an invitation to longevity with a dip in the clear waters of the legendary “Fountain of Youth” at the deLeon Springs State Park near Daytona Beach?
“We’ve been working aggressively in this Big Bend area for more than 15 years, collaborating with landowners and partnering with other agencies such as the state farm bureaus and agriculture associations, natural resource and environmental protection agencies, and the University of Florida. We’ve identified this region as important for agriculture but also important from a natural resource, iconic beauty, and recreation perspective as well,” says Budell.
Citing these water features as a window to the aquifer, he says the springs “tell us how we are doing to manage our water resources.” When spring flows are low, and with annual average of more than 50 inches of rainfall but not a large number of surface water features, the quality of the springs is a mirror that reflects the effects of land use.
Springs are designated as either urban or rural/agricultural in their respective setting, and each type encounters different forces affecting their health. In many cases, the nutrients and other contaminants are sited far from the actual spring source and may travel miles finding their way through to the aquifer. Dye studies have shown just how quickly the water can travel from its source to the spring and can provide clues to the origin and connecting flow routes.
“The karst geology and a lot of sinkholes brings groundwater into direct recharge to the springs,” explains Budell.
The Winter Breadbasket Provider
Recognizing the impending potential for aquifer disaster as Florida development has surged without pause, Budell’s agency has established close collaboration with the Florida farm community since the late 1990s, introducing best management practices (BMPs) to reduce the introduction of nitrates and phosphorus and help mitigate the impact upon springs and the Florida aquifer supply.
In Florida, he says, “There are about 18 million acres of privately owned lands: 8 million acres in forestry, 8 million acres in range, and 2 million in crop land, of which 1.8 million is irrigated, which is 90% of that acreage. These include citrus, vegetables, peanuts, cotton, corn, and berries–we’re still the winter vegetable breadbasket for the eastern half of the country.”
But he wants this highly productive breadbasket to be efficient with less impact to the environment, especially with fertilizing and irrigation.
Silver Springs, Florida
“We want to make sure that the nutrients are most efficiently used and that they [farmers] employ fertigation techniques.”
Budell explains that fertigation is a technique to apply fertilizer in water for application only as it is needed, and applied at the root zone to maximize plant absorption and reduce runoff. By testing soils for phosphorus and tissue-testing plants for nitrogen, he says, “Our whole effort is focusing on managing the root zone, to manage irrigation and not oversupply past the root zone.”
The goal to engage landowners, providing technology tools to farmers that promote improved capacity, provide better yields, and reduce harm to the environment, has been very successful.
“We have millions of dollars in research and demonstration projects with documented reduction in runoff and increases in yield. We use the soil weather stations to tell how much rainfall there is, we measure soil moisture and evapotranspiration, and all of this can show up on your cell phone in real time to control irrigation.
“It is incumbent upon us to make sure that we are providing the opportunity and impetus to continue to advance BMPs and continue to embrace new technologies and production techniques that will help agriculture transition into the next generations.”
Broadening the Net of Collaboration
Budell says there are many challenges to springs management, such as matching up land use with environmental goals as “the region is a classic example of that complexity.” And, indeed, the Water Policy Advisory Council characterizes that complexity. Members include farmers, fruit and vegetable growers, forestry, fertilizer mining, nursery growers, beef cattle, dairy, and turfgrass organizations. Alongside representatives from the public and environmental sectors such as The Nature Conservancy, Florida Audubon, Florida League of Cities, Florida Section America Water Works Association, Florida Fish and Wildlife Conservation Commission, the Association of Florida Conservation Districts and Department of Environmental Protection, and members from the five Florida water districts, they are all focused on water and the Florida springs.
While each group has its respective concern and not everyone agrees with all policies, there is no disagreement as to the intrinsic value and necessity for healthy springs as the bottom line of a sustainable, healthful water supply. During their annual meetings, members contribute both by identifying problems in their regions and respective water sectors, and by proposing strategies that will support the robust agricultural economy and ensure springshed water quality.
Recent meetings included discussion of the increase in nitrates in springs; many are above the threshold for impairment. The Florida Department of Environmental Protection (DEP) says the nitrate standard for all springs is 0.35 milligrams per liter (mg/L) at the spring boil or where the water is discharged, but some springs exceed the drinking water standard of 10 mg/L, which “translates to human health concerns.”
No Single Magic-Bullet Solution
Wendy Graham, the Carl S. Swisher Eminent Scholar in Water Resources at the University of Florida and director of the University of Florida Water Institute headquartered in Gainesville, says, “The strategy is to really understand the springs and have the information and research we need to implement solutions.”
When the Ichetucknee Springs ecosystem was suffering with the rapid development of nearby Lake City, the famed Rose Sink
dye-trace study provided some shocking facts. Divers put tracer dye in a large sinkhole called Rose Sink 6 miles northeast of the Ichetucknee head spring, and eight days later the dye appeared not only in six of the seven springs of the park, but also in toilets and drinking water of nearby residents. This was a first to demonstrate the concept of water connection and of “what goes in comes out somewhere else,” and was a sobering illustration of how protecting one individual spring must include consideration of a much broader landscape—in this case, a springshed measured not in acres, but in miles.
Unlike other aquifers where there’s a system to capture runoff, springs are recharged from multiple sources. The source of nutrient runoff may occur far from the location of the spring it contaminates. Graham says that the changes in each respective system reporting increased nitrates may be more than just farm runoff in rural areas or septic contamination in urban areas.
“Springs have a particularly difficult problem—it’s a nonpoint-source system and by definition the sources are spread throughout the contributing area, and unlike others [systems] where there’s a way to capture runoff, the recharge in this case is vertical,” she says.
Nitrate levels in most Florida springs are increasing, she notes, but agriculture can help control the runoff from irrigation by adopting the BMPs developed by the FDACS.
“We need to do a better job of irrigation using new technologies and sensor-based management, and we need to develop plants that are better at holding water in the root zone.”
But while nitrates inarguably are a severe problem, Graham cautions that the shifting ecology of most Florida springs is not a “one-problem one-solution scenario.”
“If we go in with a one hammer and one nail approach, we may not fix the problem,” she adds.
The Water Institute researchers are studying the complex dynamics of the springs and how other less obvious factors play a role, citing the relationship between algal growth and the presence of increased nitrogen and phosphorous in springs as being more complicated than in other water systems. In a spring system, algae growth is influenced by many factors including top-down (grazers such as snails) and bottom-up (nutrients and light) controls.
“We know that there are micronutrient issues that affect the grazers; we have concern if something has changed in the food, for example,” explains Graham.
“When there is a lowered flow rate of the spring there is less dissolved oxygen and consequently this affects the grazers. There is a level of uncertainty of just how to solve the problem,” says Graham, but she adds that there are two regulatory handles to work with.
“One is regulating the number of water-use permits, which would help the spring flow, and the other is compliance with the numeric nutrient criteria; those are the two tools that exist.
“At the university we are trying to understand how the underground conduits form; we need new geophysical techniques to find the flowpaths, and we need to quantify how far we can get with the current generation of best management practices,” she continues.
But it’s a juggling act to meet food needs of the population, manage the economics of development, understand how climactic situations are affecting spring flow, and create practices that incorporate the cost of tradeoffs to leave land in natural systems and not turn it into another subdivision. Not everyone will be happy with the sacrifices that are necessary, but Graham believes that all stakeholders, consumers, and policymakers are concerned, and “everyone values the springs.”
“It’s a pretty universal consensus,” she says, but she emphasizes that it’s a very complicated and costly problem that requires money and investment into the necessary research to understand the short- and long-term effects of the problems and the range of conservation measures needed.
Stepping Up to the Plate
While there’s no one magic bullet, reducing contaminants from septic tanks and improving wastewater standards are another component to address the spring’s problems.
In January, the DEP provided $1.5 million for water-related projects in northeast Florida to tackle stormwater, nutrient, and wastewater issues. Nearly half that will go to Putnam County, which the DEP says will “help fund the construction phase of a regional wastewater system that will allow the county to hook up additional residences and businesses to the system and reduce the number of septic tanks being used in east Palatka. The removal of these septic tanks is part of the county’s Basin Management Action Plan, and the project will contribute to improvements in the St. Johns River.”
According to the DEP, the St. Johns River Basin is a little over 2,000 square miles with numerous lake, swamp, and stream features and an estimated 30 or more springs; three are classified as first-magnitude springs, including Blue Spring, which offers a warm-water refuge for manatees as river water temperature drop in winter. As with many of Florida’s growth regions, this watershed has suffered diminished water quality with pressures from farming and urban development along the banks of the St. Johns. Contamination from fertilizers, erosion problems, faulty septic tanks, and an increase in quantity and flow velocity of stormwater—much of the natural floodplain was filled and paved over—have contributed to the current problems for the aquifer.
The latest funds are part of a long-term plan launched almost one year earlier in 2013, when Florida’s Governor Rick Scott announced commitment to “preserve and improve Florida’s environment.” He said then that the $1.4 billion budget for 2014–2015 includes earmarked support for “restoration projects in the Everglades, springs protection improvements, and the purchase of conservation lands,” and that this commitment is “a priority on protecting the health of Florida’s natural resources.”
In August 2014, the DEP announced the total invested in springs projects is more than $100 million in the last two years and that “during this year [2014] alone, DEP has developed a project plan to support nearly $70 million in springs restoration projects . . . to restore water quality, protect water flow, and reduce water consumption.” An estimated 330 springs will benefit from planned or ongoing basin management action plans.
According to DEP spokesperson Dee Ann Miller, the agency has been working to set minimum flows and levels (MFLs), which “protect springs and other water resources from significant harm that might result when too much water is withdrawn for human use.” Miller explains that MFLs regulate water withdrawals and also help in planning where new water sources could be developed.
The five water management districts are working with the state agency to implement an additional 28 MFLs that Miller says will be three times the number set from 2007 to 2010.
Other DEP restoration goals are setting total maximum daily loads (TMDLs). Miller says this is a scientific determination for 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.” Waters that do not meet these standards they are designated “impaired,” and TMDLs must be “developed, adopted, and implemented to clean up the water body.” This year a total of 41 springs will have TMDLs, which the DEP says is nearly double the number in place at the beginning of 2011.
Florida Springs: A Canary in the Coal Mine
More than 7 million people who visit the 100 largest springs each year bring economic value between $300 million and a billion dollars to the sunshine state, Knight says. He calls springs “the canary in the coal mine” and the valuable barometer of the health of this natural environment that is an iconic and valuable state asset and plays the essential role in the aquifer system.
Budell says new tools over time will harness more efficiencies. However, he notes, “You have to allow society time to integrate new practices in their routine. If you don’t, you set up all sorts of conflict. These didn’t get degraded overnight and we can’t fix them overnight. It’s been an unanticipated sequential impact that’s occurred as we’ve occupied the landscape, and we need to correct it.”
Wouldn’t Tarzan be thrilled!
