Silver Springs of Marion County in central Florida is the largest and one of the most well known of Florida’s first magnitude springs, with average discharge of ~ 766 cubic feet per second (cfs) (or over 550 million gallons per day).
Main Spring, Blue Grotto, and The Abyss are collectively known as The Silver Springs Group and form the headwater of the Silver River. Below the head spring area, numerous smaller springs add additional discharge within the first half-mile of the Silver River. This scenic river is the single largest tributary of the Ocklawaha River.
Timucuan Indians settled around Silver Springs in the early 1500s. They were soon invaded by the Spaniards and eventually succeeded by Seminole Indians. The Seminoles, led by Chief Osceola, eventually retreated to southern swamps when pressed by the US Government in 1835. By the 1850’s, barges carried cotton, lumber and nonperishables up the river to the growing community of Ocala. In 1860, the first steam boats made their way upstream, and from that point on, people flocked to visit the natural beauty of Silver Springs.
Flowing at over 766 cubic feet per second, Silver Springs is the largest first magnitude spring in Florida.
Silver Springs has become an internationally known tourist attraction due to its naturally clear water, healthy submerged aquatic vegetation, abundant fish and other wildlife, and its famous glass bottom boats. In addition, the spring’s crystalline water has provided the perfect underwater backdrop for many Hollywood films and television programs including six Tarzan films, Seahunt, Mutual of Omaha’s Wild Kingdom, The Discovery Channel and many others.
The park draws crowds who come to watch a variety of wildlife shows, enjoy the amusement rides, and explore the springs on the glass bottom boat rides. Silver Springs Park is contiguous with the Silver River State Park where access with boats, canoes and kayaks is possible.
In the past several decades, changes have been observed and measured in the Silver Springs hydrological system. These changes in water flow, water chemistry, and ecology of the spring system were well-documented in “Fifty-Year Retrospective Study of the Ecology of Silver Springs, Florida”, by the St. Johns River Water Management District.
The dominant change in the water chemistry has been an increase in nitrates from an average background level of less than 0.05 milligrams per liter (mg/l) to an average above 1 mg/l which represents about a 20- fold increase. There is also concern about a possible decrease in water clarity, compared to past observations. The main sources of nitrate in the Silver Springs Group can be broken down into inorganic and organic sources. Based on the land use in the springshed, inorganic nitrates could come from fertilizer applied to pastures, golf courses, lawns, and crops; organic nitrates come from wastewater from septic tanks and municipal wastewater application sites and livestock, such as the large number of horse farms in the springshed.
During this same time period, the plant and animal life of Silver Springs and Silver River has changed, also. An increase in algal growth has been documented on the white sandy bottom and the dominant submersed aquatic vegetation (SAV), strap-leaf sagittaria (Sagittaria kurziana) and eelgrass (Vallisneria americana) in the spring run. There has been an overall decline in biomass of several species of fish including catfish, mullet and gizzard shad since the 1950s. Large numbers of an invasive nonnative sail-fin catfish have become established in the spring run.
There is an apparent measured decrease in flow from the Silver Springs complex, although there is some uncertainty about both its extent and cause. The St. Johns River Water Management District is expected to set minimum flows and levels in 2013 to prevent significant harm to the water resources or ecology of the springs.
Other stakeholders within the Silver Springs recharge basin have already taken actions that either directly or indirectly affect the restoration of the springs, ranging in scale from individual water conservation efforts to modified agricultural practices, to county-wide ordinances. The Silver Springs Basin Working Group, established in 1999, was the original forum for stakeholders representing federal, regional, state, and local agencies, local governments, the business community, agriculture, environmental groups and other concerned citizens to take restoration actions. Due to legislative budget cuts, the working group funding was cut, but restoration efforts continue through the State Total Maximum Daily Load (TMDL) and Basin Management Action Plan (BMAP) process.
One initiative supported by the working group was the acquisition of a 4400-acre property north of Silver Springs, purchased by the state in 2007. The purchase kept this especially vulnerable property in a natural condition and prevented pollutant loading from any potential development of the area. The property is now being managed by the state Division of Forestry as Indian Lake State Forest.
Marion County has used information from groundwater travel time studies and other research to establish spring protection zones for Silver Springs and, Rainbow Spring. It has also adopted two spring protection provisions in its comprehensive plan. One provision addresses septic tank and waste water treatment plants in the spring overlay zones for Silver and Rainbow Springs and the other addresses the use of fertilizer in non-agricultural settings in the county.
Plan for Silver Springs
A draft restoration plan was generated by Silver Spring stakeholders via contract with Normandeau Associates Inc., and through the leadership of Pete Colverson. You can access the report by clicking on the link below.
Draft restoration plan for Silver Springs and river - 3.4MB
Presentations from the Special Meeting on Silver Springs Flow, held June 28, 2011.
Special Meeting Notes June 28, 2011 - 503.2KB
Changes in Silver River Stage/Flow Relationships - 6.9MB
Silver River & Springs MFLs - 2.9MB
Presentations from the May 12, 2011 working group meeting. Please see the links below:
Silver Springs Health Report Card May 2011 - 3.2MB
Silver Springs Basin BMP Update - 2.0MB
Marion County Regulation Update - 746.5KB
Silver Springs Water Quality
Click the fact sheet below for a summary of information about the working group and water quality at Silver Springs.
Springshed Recharge Area*
This map shows the 764 square mile springshed or spring recharge area where rainfall enters the ground and flows through the aquifer to Silver Spring. Pollutants from fertilizers and pesticides, faulty septic systems and stormwater runoff in the springshed can harm the quality of water in the aquifer, the source of our drinking water and water flowing from Silver Spring.
Groundwater flows are dynamic, and the area covered by the springshed should not be interpreted as absolute or static, as the springshed may fluctuate due to groundwater withdrawals, drought, heavy precipitation or other factors. For more information about the springshed data, download the document below.
View images of Silver Springs and Silver River.
Florida Department of Environmental Protection
Ground Water and Springs Protection
Rick Hicks, PG, PG Administrator
Phone: (850) 245-8229
Contact for: General springs information
Basin Management Action Plan Development Program
Mary Paulic, Basin Coordinator
Phone: (850) 245-8560
Contact for: information on TMDL and BMAP development and implementation (Note that a TMDL for Silver Springs and the Silver River has been finalized).
Local Government and Water Resource Agencies
- City of Ocala
- Florida Department of Agriculture, Office of Agricultural Water Policy
- Ocala/Marion County Utilities
- St Johns River Water Management District
- Alachua County
Citizen Stakeholder and Watershed Organizations
- Howard T. Odum Florida Springs Institute
- Marion Audubon Society
- Florida Native Plant Society
- Friends of Silver Springs State Park
Parks and Conservation Areas
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