With more than 1,000 freshwater springs located in the north and central part of the state, Florida has the largest concentration of springs in the world. Much of the Sunshine State’s development throughout history can be traced to the presence of this unique natural resource. Freshwater springs, a source of drinking water, recreation, and irrigation for farming, have drawn settlers and tourists to Florida for centuries.
Today, these springs continue to provide important economic and recreational benefits while also playing a critical role in the health of local ecosystems. However, for several decades Florida’s springs have been threatened by pollution, drought, and increased development. Projects now underway reflect a broad-ranging effort to restore and protect these vital natural resources.
‘Old Florida’ attractions
Florida’s Springs are best known for their recreational value. These “Old Florida” attractions include Weeki Wachee Springs, a freshwater spring that has been a mainstay of Florida tourism since 1947. This first-magnitude spring, which discharges 112 million gallons a day (mgd) on average and feeds the seven-mile-long Weeki Wachee River, is the centerpiece of a 538-acre park near the Gulf Coast.
Warm Mineral Springs, known as “The Fountain of Youth,” is the only warm water mineral spring in the state, and the largest in the world. Located in Sarasota County, the spring is on the National Register of Historic Places and is among the state’s top tourist attractions. Wakulla Springs State Park near Tallahassee features the world’s largest and deepest freshwater spring along with more than 80 additional sinkholes and streams. The park is also listed on the National Register of Historic Places and is a National Natural Landmark.
Ichetucknee Springs State Park, in Columbia County, is a premier site for canoeing, kayaking, and tubing, with the rapidly flowing Ichetucknee River stretching for five miles until it joins the Santa Fe River. Homasassa Springs State Wildlife Park is a showcase zoo for native wildlife, including West Indian manatees, alligators, crocodiles, black bears, and bobcats.
Adventurous visitors are drawn to parks such as Manatee Springs State Park, Ginnie Springs, and Blue Spring State Park, which are well known for cave diving, scuba diving, and snorkeling. With 28,000 feet of explored passageways, Wes Skiles Peacock Springs State Park in Suwanee County has one of the longest underwater cave systems in the continental U.S., an attraction to many experienced and ambitious cave divers.
Many springs that were originally operated privately are now owned by the state and under the care of the Florida Park Service. Twenty state parks feature freshwater springs. In addition, numerous local parks and recreation areas are centered around springs. Visiting springs in Florida is a way of life for both residents and tourists. Springs protection efforts must take this into account and allow for this continued use while providing protection.
An essential natural resource
While Florida’s freshwater springs have long helped to sustain the state’s tourism and recreation industries, with an estimated direct economic value of more than $300 million per year, their most important role lies in their ecological value. The springs, along with the rivers, lakes, and bays that they feed, are home to numerous species of plants and animals, ranging from eelgrass, lilies, and bald cypress trees to freshwater shrimp, birds, turtles, otters, alligators, and Florida’s treasured manatees.
Springs are also a vital component of the Floridan Aquifer System, which supplies most of the state’s drinking water. This vast groundwater source spans 100,000 square miles in the southeastern U.S., including all of Florida, and supplies potable water to millions of people as well as water for agricultural irrigation and industrial purposes. The Floridan Aquifer System has historically supplied about 10 billion gallons per day of fresh water to Florida’s springs. More than 750 Floridian springs are part of the system, and the health of these springs is a strong indicator of the quality of the aquifer.
Florida’s unique geology
A freshwater spring occurs where water flows directly from the aquifer to the earth’s surface (see Figure 1). When the aquifer fills, the subsurface pressure causes water to flow up to the land surface through openings called spring vents. Florida’s unique geology, including its layers of highly porous marine limestone, contributed thousands of years ago to the prevalence of springs in the state. The porous limestone formations hold and transport more water than formations elsewhere in the country. The capacity of these formations, combined with relatively high rainfall amounts and subsurface water flow, resulted in the creation and ongoing sustenance of Florida’s freshwater springs.
Water flow can vary considerably, based on aquifer water pressure, rainfall, size of the spring basin, and the size of spaces, including caves, within the rocks. Groundwater withdrawal for consumer use can also greatly impact the flow of springs. Some springs flow only after significant rainfall events, while others flow at the rate of hundreds of millions of gallons per day. Florida has 33 magnitude 1 springs, defined as a spring that discharges water at a rate of 100 cubic feet per second.
Challenges and threats
Healthy springs are typically characterized by adequate flow, water clarity, dense aquatic vegetation, and the abundance and diversity of native wildlife. Unsustainable water consumption, runoff from farms and residences, damaging invasive species, unrestricted recreational use, and the abundance of onsite sewage and disposal systems are among the many threats to the preservation and health of natural springs.
The Florida Department of Environmental Protection (FDEP) created a detailed list of specific threats to Florida’s springs, including:
- landscaping and lawn care, including excessive water use and the use of fertilizers and pesticides;
- sprawl and development, including encroachment on natural spaces that serve as important recharge areas for the aquifer and springs;
- stormwater runoff, which often carries clogging sediments and chemical pollutants into waterways;
- water consumption and overuse resulting from the demands of people, agriculture, and industry;
- illegal dumping, including disposal of garbage and chemicals into sinkholes that contaminate springs and the aquifer;
- row crop agriculture, leading to the use of harmful fertilizers and pesticides;
- livestock farming, resulting in tons of animal wastes that contaminate springs and the aquifer;
- golf courses, which occupy approximately 200,000 acres of land in Florida, requiring excessive use of fertilizers and pesticides;
- recreational impacts, including trampling of native vegetation, erosion of shorelines, littering, and damage from motor boats and other vessels; and
- invasive species, often encouraged by nitrates in the water, leading to damage to springs and spring runs.
Degraded springs may have higher water temperatures and nitrate levels and lower levels of dissolved oxygen and water clarity. The most common form of pollution is nitrate, a form of contamination that results from many of these threats, including septic systems, sewage plants, agriculture, and fertilizer.
According to Robert L. Knight, Ph.D., founder and president of the Howard T. Odum Florida Springs Institute, “At higher concentrations [of nitrate], what we see is a flip where the system stops supporting the submerged aquatic vegetation — like the tape grass and the eelgrass — and it starts supporting more and more algae and a different kind of algae: filamentous algae.”
More than 60 percent of Florida’s springs are currently impaired by nitrate, according to FDEP standards. The overwhelming presence of algae, often in the form of the dense algal mats, can ultimately lead to the demise of the native aquatic plants, fish, and wildlife that typically thrive in the springs-based ecosystems, while also dramatically degrading the quality of water in the aquifer. These environmental degradations also reduce the recreational and economic value of these resources.
Restoring the health of springs
FDEP, the Florida Springs Council (a consortium of 36 organizations), the Florida Springs Institute, and water management districts (WMDs) across the state clearly recognize the critical importance of Florida’s springs and the need to pursue a variety of restoration and protection initiatives. Several spring restoration projects have been completed or proposed. These initiatives focus on pollutant reduction, water conservation, and more recently, land purchases, land easements, and agricultural conversions.
Nearly $270 million has been committed in state and local investment during the last four years to protect the state’s springs. Thirty-five projects of all sizes and scopes were identified for FY 2016-2017. While the funding commitment has been encouraging, Florida’s springs restoration and protection efforts will be challenged to keep pace with anticipated population growth, increased water use, and growing agricultural fertilizer use.
Funded initiatives currently include measures that fall into three categories:
- projects in and around springs to prevent and repair physical damage, including shoreline stabilization, erosion control efforts, access control, and improving recreational infrastructure;
- projects that are remote from springs but reduce pollution in the springshed, including replacement of septic systems with central sewer systems, improving drainage systems, enhancing groundwater recharge, retrofitting drainage retention areas, replacing stormwater pipes, rehydrating wetlands, water conservation measures, and incentivizing low-nutrient land use; and
- projects that conserve water.
The following case studies represent two of these three types: a septic-to-sewer project near Wakulla Springs and a physical restoration project at Wacissa Springs.
Wakulla Springs, south of Tallahassee, is another Old Florida attraction that has long been a destination for tourists. The spring and its surrounding 2,860 acres were purchased by the state in 1986, creating the Edward Ball Wakulla Springs State Park.
In 1997, the first of the “choking” hydrilla began to appear at the springs. Apple snails and limpkins also began to disappear. The water is now rarely clear enough to permit the park’s popular glass bottom boat rides. Since the 1970s, scientists have documented a decline in water quality, particularly with regard to nitrates.
Until 2010, the City of Tallahassee’s wastewater treatment plant was the largest source of nitrate pollution in the Wakulla Springs Basin. After a $200 million upgrade to the wastewater treatment plant and additional water quality improvement projects in the springshed, septic tanks may now be the main contributor to the nitrate pollution in the Wakulla springshed.
In some rural areas with large lots, septic tanks are geographically separated in a way that precludes the economic viability of wastewater collection and transport to a centralized treatment system. In these circumstances, plans are underway for enhanced onsite sewage treatment and disposal methods. These systems can be active or passive. Active systems typically rely on aeration, while passive systems typically involve an enhanced drainfield media.
Four projects in the springshed — two in Wakulla County and two in Leon County — have ongoing springs protection projects to connect homes on septic systems to central sewer. The two neighborhoods in Wakulla County where the density of lots and proximity to centralized treatment systems were identified as suitable for a “septic-to-sewer” type of springs protection project are Wakulla Gardens and Magnolia Gardens.
Wakulla Gardens is a residential neighborhood in Wakulla County located in the Wakulla springshed. Some lots have access to city water, but most are on wells, and all 3,000 lots are on septic tanks. The county plans to expand the wastewater collection system in phases to abandon septic tanks and connect these lots to an expanded collection system.
Magnolia Gardens is a similar neighborhood in Wakulla County, also in the Wakulla springshed. Magnolia Gardens is closer to an existing conveyance system, so the project can remove more lots for the same budget since the offsite conveyance system is shorter. Wakulla County, in partnership with the Northwest Florida Water Management District, is working to bring these two neighborhoods into the centralized wastewater treatment plant. The project is being funded in phases. Phases I and II will remove 716 residential lots from septic to a centralized treatment system out of the springshed.
For years, Wakulla County has also been proactively working on plans to improve groundwater quality by reducing pollutant loading. The county is continuing this effort by identifying large sources of potential negative impacts, and working on plans to reduce these impacts. These efforts include wastewater treatment plant upgrades, identification and elimination of inflow/infiltration, implementation of a reclaimed water system, and expansion of the collection system to reduce septic tanks. Three county projects have been identified for the Wakulla Gardens and Magnolia Gardens communities:
Otter Creek Wastewater Treatment Plant Upgrade — This project will upgrade the existing plant capacity from 0.6 mgd to 1.2 mgd, and is currently being designed and permitted. The upgrade will also provide for filtration and disinfection to Public Access Reuse Standards. The existing plant is at capacity and cannot support any new connections, so this project will allow for future development, which will also increase wastewater system revenues. Additionally, this project will increase the treatment level of the wastewater to provide for a higher level of nutrient removal, which increases the overall environmental benefit.
Shell Point Wastewater Treatment Plant Abandonment — This project includes abandonment of an existing wastewater treatment plant in the coastal community of Shell Point. Talquin Electric Cooperative owns this plant and is constructing a conveyance system to connect to the county’s existing conveyance system. This project, nearly complete, will provide the county additional revenues for the wastewater treatment system and will provide the environmental benefit of removing the wastewater effluent discharge from the sensitive coastal area.
Wildwood Reuse Line — This project includes construction of an 8-inch reuse main from the wastewater treatment plant to a local golf course. The new reuse main will allow for a minimum of 300,000 gallons per day of reuse irrigation water for the golf course. The project reduces groundwater consumption for irrigation and allows for effective disposal of wastewater effluent. The project has been constructed and is awaiting upgrades at the Otter Creek Wastewater Treatment Plant before it can be put into service.
Removal of existing septic systems, stormwater retrofits, and other water quality improvement projects have significantly reduced nitrate concentrations in Wakulla Spring. During the last 20 years, nitrate concentrations have been reduced by about 50 percent. This reduction does not yet include the work at Magnolia Gardens and Wakulla Gardens. In Wakulla County, the Magnolia Gardens and Wakulla Gardens septic-to-sewer projects will help protect Wakulla Spring, one of the largest and deepest freshwater springs in the world.
The Wacissa River Springs project in Jefferson County, located within the Suwannee River Water Management District, reflects another approach to springs protection. Over the years, access to the spring for recreational use has been unlimited. The spring and spring run have been the sites of “mudding” by locals, a popular activity where trucks enter the water and spin in the mud. This use as well as other typical uses have contributed to the degradation of the spring. There are no stormwater management facilities and the parking lot is dirt. Over time, the banks have eroded and sediments have filled the spring vents from both bank erosion and lack of stormwater management facilities. Invasive species are choking the area, making swimming and boating a challenge.
The Board of County Commissioners created a citizens’ panel to develop an improvement plan, now being implemented in phases. Working in partnership, the Jefferson County and the Suwannee River Water Management District (SRWMD) are removing sediment and stabilizing the spring banks to control erosion. The project involves removal of vegetation, silt, and debris; and protecting the spring bank by defining access points and stabilizing the shoreline in the vicinity of the spring head and run.
Debris was removed from the spring head, including concrete rubble and old railroad ties. Invasive plant species were also removed. Large boulders were used to prevent vehicles from approaching the spring. Similar boulders were used to ring the shoreline and designate access points for swimmers. The shoreline along the spring run was stabilized and a floating dock installed to discourage boaters from climbing on the bank. Swim ladders and stairs were also installed to discourage swimmers from climbing on the shoreline to enter and leave the swimming area. Phase I of the Wacissa Springs restoration was completed in 2015 with funding from both Jefferson County and the SRWMD.
Phase II of the springs restoration has been funded and is expected to begin in the fall of 2017. This phase will include additional shoreline stabilization, sediment removal, exotic plant removal, stormwater management facilities, shoreline boardwalk, and impervious parking. Phase II is estimated to remove 59,431 pounds per year of nutrients. Additional grant funding has been secured to provide composting restrooms, picnic shelters, and additional shoreline boardwalks.
Protecting springs: Florida’s unique legacy
The commitment to funding during the next several years is an opportunity to make substantial and lasting improvements to Florida’s springs. The challenge lies in selecting the most beneficial projects and using resources wisely, while keeping pace with population growth.
Florida is fortunate to have strong alliances between state and local partners, as well as the advocacy and support of groups such as the Florida Springs Council and the Florida Springs Institute. Many water management districts throughout the state are taking the initiative to implement meaningful projects that will restore and protect freshwater springs. These projects will be instructive in continuing this effort and protecting Florida’s vital and unique natural resources for future generations.
Debra Preble, P.E., is a senior associate in the Tallahassee, Fla., office of Dewberry (www.dewberry.com).