Fanning Springs, once a magnificent first magnitude fountain of clear, blue, fresh water emerging from the ground at a rate of about 110 cubic feet per second (in 1930) is today a second magnitude spring with a flow estimated to be between 10 and 100 cubic feet per second.
The spring pool is about 207 feet by 144 feet, and the main funnel-shaped vent is about 20 feet deep. Several other small seeps create sand boils and trickle into the spring pool from limestone outcroppings on one end.
The spring is located inside Fanning Springs State Park on the Suwannee River in Levy County, Florida.
The Most Impacted Spring in Florida?
Fanning Springs may also be the most impacted—by development—of all of Florida's once-first magnitude springs. The spring's flow has been disrupted by enormous withdrawals of water from the Floridian Aquifer while the water itself has become highly contaminated with nitrates from fertilizers and septic tanks.
Fanning Spring was historically a first magnitude spring, but is now considered a second magnitude. Flow reductions are the result of increased groundwater pumping due to highly populated areas throughout the state, such a Jacksonville, which alter the potentiometric surface of the aquifer and therefore alter the springshed boundaries as well. Aquifer drawdown is also due to agricultural and other industrial processes within the springshed which permanently remove a certain percentage of the water consumed from the groundwater supply.
Also the spring's popularity as a recreational area combined with its shallow spring pool, its short run to the Suwannee River (450 feet), and nutrient runoff from the surrounding landscape, have caused most of the natural vegetation to disappear and nutrient levels are the second highest of any springs (4.8 milligrams per liter) in the state.
Fanning Spring was historically a first magnitude spring, but is now considered a second magnitude. Flow reductions are the result of increased groundwater pumping due to highly populated areas throughout the state, such a Jacksonville, which alter the potentiometric surface of the aquifer and therefore alter the springshed boundaries as well. Aquifer drawdown is also due to agricultural and other industrial processes within the springshed which permanently remove a certain percentage of the water consumed from the groundwater supply.
Also the spring's popularity as a recreational area combined with its shallow spring pool, its short run to the Suwannee River (450 feet), and nutrient runoff from the surrounding landscape, have caused most of the natural vegetation to disappear and nutrient levels are the second highest of any springs (4.8 milligrams per liter) in the state.
There are two springs at the park, Fanning and Little Fanning. The park is a popular site for recreation and offers swimming, volleyball, hiking, and camping. The swimming area includes a dive platform over the main boil, which averages around 18 feet deep, while the rest of the swimming area is inches to 6 feet deep.
Large Agricultural Springshed
The springshed (land area that drains water to a particular spring) of Fanning Springs is comprised of 450 square miles of northwestern Levy County and southwestern Gilchrist County. 75% of the land use in these two counties composed of pine plantations, improved pasture, hardwood conifer forests, wetland-mixed forests, temperate hardwood forests, and forest regeneration areas.
Nitrates = Lyngbya
Nitrate (NO3) levels have been rising exponentially at Fanning Springs since the 1970’s. Fanning Springs, in fact, has the second largest NO3 loading of any spring. These high nitrate levels not only cause algal blooms, but they start to stress the species present and to cause extinctions.
The high nitrate concentration (4.8 mg/L) is almost 100 times the background level (0.05 mg/L) and rising. Annually, 1200 tons of nitrate are applied as fertilizer to the agricultural areas of the springshed in Gilchrist county which result in an annual loading of around 2.46 mg/L or 50% of that found discharging from the spring. The result is heavy concentration of cyanobacteria Lyngbya seen clinging to the steps and railing of an entrance
to the swimming area.
The high levels of nitrate at Fanning Springs are the result of several inputs. The dominant land use inside the Fanning Springs springshed, which spans parts of Gilchrist and Levy County, is agriculture. Based on fertilizer sale records it is clear that agriculture is responsible for a significant concentration of nitrates entering the groundwater, which eventually discharges at the spring. Other sources of nitrate include the urbanized areas inside the springshed that use septic tanks that provide minimal treatment before discharging high concentrations of nitrogen into the groundwater.
Springs' Importance Forgotten
Springs are valuable natural and scenic resources that have played an important role in North Florida‘s history. Native Indians located their villages near springs and many springs were used by 19th century Floridians as a source of drinking water as well as a place to take a cool swim in the summer. Some spring runs were modified to funnel the water through channels to power mills. Early in the 1900’s, resorts were developed around sulfur springs due to the perceived medicinal effects of bathing in these springs. Today, springs in the region continue to attract visitors who enjoy their beauty and recreational opportunities.
Florida's Shame
Thanks to the Springs Initiative, created in 2001, our knowledge of the Suwanee River system has expanded greatly. Hundreds of new springs have been discovered, some within the banks of the river and others further inland. Fanning Springs was one the largest springs flowing directly into the Suwanee River until relatively recently. Florida, however, has invested a paltry $15 million over a decade, of its $80 billion annual budget, to protecting and restoring springs.
How do Springs Function?
Springs are the surface evidence of a vast underground water resource, the Floridan aquifer system, which supplies most of the State's drinking water. The amount of water that flows from springs depends on many factors, including the size of the caverns within the rocks around the springs, the water pressure in the aquifer the size of the spring basin, and the amount of rainfall. Human activities also influence the volume of water that discharges from a spring—ground-water withdrawals in an area like Fanning Springs, reduce the pressure in an aquifer, causing water levels in the aquifer system to drop and ultimately decreasing the flow from the spring.
A massive, thick sequence of carbonate rock underlies the entire Suwanee River Water Management District (which has authority over springs within its political boundaries) and constitutes the Floridan aquifer system. The majority of the rock is limestone, which is calcium carbonate. The remaining rock is dolomite, which is calcium-magnesium carbonate.
Dolomite is basically harder than limestone but has similar hydrogeologic properties. Unconsolidated material (sand or clay) usually overlies the Floridan aquifer system. However, once the carbonate rock is encountered in the subsurface, it is rare to find sand or clay (except in sinkhole fill). The carbonates of the Tertiary period are up to 2,500 feet thick in the SRWMD and are saturated with water. The potable portion of this aquifer generally ranges between 250 and 1,200 feet below land surface.
As rainwater enters or "recharges" the aquifer, pressure is placed on the water already present. This pressure moves water through the cracks and tunnels within the aquifer, and this water flows out naturally to the surface at places called springs.
The Floridan aquifer system extends throughout peninsular Florida and the southern portions of Alabama, Georgia, and South Carolina. It generally underlies all of the Southeastern Coastal Plain and partially extends under the Atlantic Ocean and the Gulf of Mexico.
At the zenith of the last ice age (approximately 13,000 years ago), sea level was nearly 300 feet below its present altitude. It was from that time to the present that this regional aquifer system filled with fresh water. As rain water recharges the aquifer system, the carbon dioxide in the rain water creates carbonic acid. This weak acid in the rain water dissolves the limestone and creates cavities and caverns in the aquifer. This results in a type of land form known as karst. A karst region typically lacks well developed surface drainage and has many sinkholes and springs. Also, a high percentage of rainfall will recharge directly into the aquifer in a karst region.
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| The Suwanee River, looking SW. I was shocked by the amount of floating garbage in the river. |
The Floridan aquifer system is the water source for all of the springs in North Central Florida, as well as the major source of drinking water in North Central Florida.
Phillip, hiking in the swamps along the Suwanee River trying to get some better shots of the garbage and debris along the river's banks.
Flow Level Importance
Flow level is important in Fanning Springs due to its recognition as a thermal refuge for manatees. Given that manatees require a certain water depth in order to be able to reach a spring (at least 5 ft), it is often impossible today for manatees to seek refuge here.
Other issues affecting the springs are structural, including a floating boat dock and a seawall which limit the spring’s ability to support manatees, and other flora and fauna that a natural slope would allow, such as turtles and wetland plants.
The lack of submerged aquatic vegetation (SAV) has occurred relatively recently. Before the spring became a state park in 1997 it still had a lot of SAV in the spring and spring run. Since it has been made a park, thousands of visitors a year come to swim and wade in its shallow spring pool. This disturbs the bottom soil and makes SAV growth nearly impossible. The spring run is subject to occasional dredging in order to support boat travel to the floating boat dock that separates the boats from the swimming area. This dredging is responsible for the lack of SAV growth in the spring run.
The spring run is about 100 feet wide and flows only 450 feet before it discharges into the Suwannee River. A boardwalk extends through an old-growth floodplain swamp, passing a enormous cypress tree, to the east bank of the Suwannee. Little Fanning Spring is hidden in the woods about 500 feet south of Fanning Spring and also runs a short distance to the Suwannee.
Due to its high-volume discharge, Fanning Spring rarely reverses its direction of flow, as do many other Suwannee River springs, but in recent drought years, “brown-outs” have become more common when the tannin (tea-colored) river backs up into the run and covers the spring.
When rivers flood, the pressure created by rising floodwaters causes many springs within the Suwannee River Basin to reverse flow and bring river water into the aquifer. This reverse flow is an important part of groundwater recharge and the health of the caves associated with the springs.
Pond Scum (Lyngbya)
The floating boom at the end of the swimming area holds back a massive mat of Lyngbya which is commonly referred to in Florida as "pond scum." Seeing that much Lyngbya in a swimming area, in spring is a pretty good indication that you might not want to swim in that water.
Lyngbya is not a plant, a fungus, a bacteria, or a true algae. It is a primitive form of life called a Cyanobacteria, a blue-green algae cappale of photosynthesis even in low light conditions. It will quickly cover a pond rising 15 or more feet from the bottom and forming thick, slimy mats.
Resurrection Fern
Resurrection fern (Pleopeltis polypodioides (L.) Andrews & Windham) covers the trees. On the Gulf side of Florida there were enough showers to bring this plant back to life. We're still waiting on the Atlantic side for some real rain.
The picnic area at Fanning Springs State Park up the hill from the spring.
Suwanee River Sunset
Danger
Jumping Sturgeon
What? Yeah. During warmer months when you hear a splash in the Suwanee River it may be a Gulf Sturgeon (Acipenser oxyrinchus destol) hurtling itself in magnificent leaps out of the water. Sturgeons are primitive, bottom-dwelling fish. They come into rivers to spawn in the spring and summer months and remain in fresh water while young. Older juveniles and adults are commonly found in rivers, estuaries, and marine environments.
The sturgeon's skin is embedded with bony plates instead of scales. As it weighs up to 300 pounds and reaches a length of 9 feet, one should beware if a sturgeon comes crashing into your small boat. The great fish has a life span of at least 80 years and will starve itself while spawning in the Suwanee. The fish may lose 100 pounds of its massive weight before returning to the Gulf of Mexico.
Personally, from seeing the awful pollution in the Suwanee River, I don't think I'd eat there either.
We've Been There, Done That:
Yeah. Enough Said.
Royal Caribbean's Brilliance of the Seas Sails under Florida's Sunshine Skyway Bridge over Tampa Bay
Sand Key Lighthouse
Proof of Global Warming if you Ever Needed It. In 1827 there were trees and houses and. . .well, an island. Today it is under a few feet of water.