Discover Florida's Freshwater Springs
Florida is blessed with one of the largest concentrations of freshwater springs in the world. These amazing ecosystems provide habitat for manatees and many other unique species as well as recreational opportunities for residents and visitors. They also provide a unique glimpse into the health of our aquifer.
The Water Channel
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The Story of Water in Florida
Water is Florida's lifeblood. It is fickle. Abundant one year. Scarce another. Yet, everything that is Florida is defined by the quality of its water resources -- and deserves all the protection we can provide.
The Water Channel
Video and Multimedia
Protecting Florida's Groundwater Supply
Florida's aquifer - the source of drinking water and water flowing from its springs - is vulverable to overuse, pollution and drought. Protecting the aquifer is one of DEP's highest priorities. Learn about efforts in the Tampa Bay region to diversify water resources.
Learn About Your Watershed
St. Marks River Watershed
Watershed Stats
Size of Basin: The two watersheds cover approximately 3,600 square miles of north Florida and south Georgia. The Ochlockonee watershed's total area is 2,416 square miles, with approximately 1,080 square miles in Florida. The Apalachee-St. Marks watershed drains 1,204 square miles.
Major Cities and Towns: Tallahassee, Woodville, Quincy, Bradfordville, Havana, Greensboro, Gretna, Monticello, Crawfordville, Sopchoppy, St. Marks, and Panacea
Counties: Leon and Wakulla Counties, significant parts of Gadsden and Jefferson Counties, and smaller parts of Liberty and Franklin Counties
Major Water Features: Ochlockonee River , Ocklawaha Creek, Bradwell Bay, Sopchoppy River, Ochlockonee Bay, St. Marks River, Wakulla River, St. Marks Spring, Wakulla Springs, Apalachee Bay, Munson Slough, Ames Sink, Spring Creek, Spring Creek Springs System, Lake Munson, Lake Jackson, Fred George Sink, Meginniss Arm Branch, Jackson Heights Branch, Lake Lafayette Chain of Lakes, and Lafayette Creek
Overview
In contrast to the Ocklockonee watershed, the St. Marks River watershed is not continuous for most of its course. However, the southern coastal drainage system is composed of local streams draining coastal regions. The main stem of the St. Marks River is the only somewhat continuously connected portion of the watershed.
The headwaters of the St. Marks River lie in the Tallahassee Hills of northeastern Leon County. The St. Marks remains swampy and poorly defined as it flows southward to the Cody Scarp. From just north of the Leon-Wakulla County line, the St. Marks River enters the Woodville Karst Plain and is fed by Floridan aquifer springs, becoming wider and clearer as more ground water enters from spring flows.
Near the Leon-Wakulla County line, the St. Marks River flows southward to Natural Bridge, where it disappears into a sinkhole, eventually re-emerging at St. Marks Spring as a spring-run river that is considerably larger, with different chemical characteristics than the stream that disappeared at Natural Bridge. Several springs rise and disappear underground in this area.
In east-central Wakulla County, the St. Marks joins with the Wakulla River, its largest tributary. The Wakulla, a classic spring-run river, originates at Wakulla Springs and flows south for approximately 10 miles to its confluence with the St. Marks River. From there, the St. Marks River widens and flows in a dredged channel to Apalachee Bay, approximately 3 miles to the south. Tidal effects extend upstream in both the St. Marks and Wakulla Rivers for about 6 miles from the river mouth.
There are 329 lakes in the St. Marks watershed, totaling 11,892 acres. Lake Miccosukee, one of the largest, is grass filled and contains only small, open water areas. It is connected by small streams to a wetland area and sinkhole to the south. Lake Lafayette is an area of freshwater marsh and limited open water on the eastern side of Tallahassee. It consists of four separate parts: Upper Lake Lafayette, Lake Piney Z, Alford Arm, and Lower Lake Lafayette. Its watershed includes the eastern part of the city, as well as unincorporated residential and undeveloped areas east and northeast of the city. Like other lakes in the region, it periodically drains through sinkholes. Water levels are partially maintained by a series of man-made dikes that divide the lake into three segments.
The Wakulla Spring-Leon Sinks Cave system is the longest underwater cave in the United States and the fourth largest underwater cave in the world.
In the Woodville Karst Plain, there are hundreds of small lakes and ponds. These are deeper and steeper than those in the Tallahassee Hills and may have formed in collapsed sinkholes. There are also several larger, shallow lakes that formed in solution depressions in the southern part of the St. Marks watershed. The larger natural lakes in this area include Lake Ellen and Otter Lake in Wakulla County. In the St. Marks National Wildlife Refuge, several large shallow impoundments are manipulated to provide waterfowl habitat. The largest include East Pool and Stoney Bayou Pool.
Human Impacts
Out of more than 50 lakes and ponds within the city of Tallahassee, most receive urban stormwater runoff and many have become degraded by nutrients and sedimentation. The Lake Munson drainage area, the largest and most urbanized in the region, drains approximately 57 percent of the urban Tallahassee area. For more than 60 years, Lake Munson received a heavy load of nutrients, toxics, and sediments from stormwater runoff and treated sewage effluent. In 1982, it was classified as hypereutrophic and the seventh most degraded lake in the state. The discharges of treated sewage were eliminated in 1984, improving water quality to the point that the lake was reclassified as eutrophic.
However, runoff from more than 23,000 acres, including more than half of Tallahassee, continues to flow into Lake Munson from Munson Slough. Problems observed in recent years include fish kills, algal blooms, invasive exotic species, high nutrient and bacteria levels, low dissolved oxygen levels, reduced numbers and low productivity of game fish, and reports of fish with sores. Pesticides and metals concentrations are found in amounts that are 10 to 100 times greater than other area lakes. The accumulation of organic muck, degraded water quality, and reduced water depth lowered fish biomass by at least 75 percent between 1976 and 1987. As a result, sport fishing was all but eliminated. In addition, water flowing from Lake Munson enters a series of sinkholes and flows eight miles underground to Wakulla Spring, contributing to increased nutrient levels in the spring and river.
Invasive aquatic vegetation is also a problem in Wakulla Spring. Dominant invasive plants include hydrilla, water hyacinth, and water lettuce. Although hydrilla has been present in the lower Wakulla River for years, it was just discovered in the Wakulla Springs pool relatively recently, where it has quickly formed dense beds and replaced native eelgrass. There appears to be a correlation between hydrilla growth and increased nutrient concentrations in the spring water. The city of Tallahassee's Southwest Farm Wastewater Reuse Facility has been identified as a principal source of nitrate in ground water that flows to Wakulla Spring. Other sources of nitrogen in the ground water flowing from Wakulla Spring are believed to come from the thousands of septic tanks that exist throughout Wakulla County and southern Leon County.
There has also been a conspicuous decline in the limpkin population along the Wakulla River. The decline of this state-listed species is related to the disappearance of apple snails, a primary food source. It is thought that their decline may be related to the hydrilla infestation. The accelerated growth of dense algal mats has also been observed in the Wakulla River; this may be caused by the increased nutrient concentrations discharged by springs.
In recognition of these impacts, FDEP, the Northwest Florida Water Management District (NWFWMD), and local governmental, scientific, educational, and citizen organizations are working to develop strategies for protecting and restoring water quality and quantity in the St. Marks Basin.
Interesting Facts:
- The St. Marks River disappears into a sinkhole at Natural Bridge and emerges at St. Marks Spring as a spring-run river that is considerably larger and has different chemical characteristics. Wakulla Springs is one of the largest and deepest freshwater springs in the world, with an average discharge of 252 million gallons per day.
- The Wakulla Spring-Leon Sinks Cave system is the longest underwater cave in the United States and the fourth largest underwater cave in the world.
- In December 2007, divers from the Wakulla Karst Plain Project set two world records, including the longest cave dive between two entrances and the longest traverse in a deep cave by traveling a distance of nearly seven miles. The feat required the divers to be under water for more than 20 hours.
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