Crescent Beach Submarine Spring is located 3.9 km from the coast of Florida.

The ocean ground at this location is some 18 m deep but the spring vent is at the depth of 38 m. This “hollow” or “spring pool” has a diameter of some 25 m.

On a calm day the spring boil can be seen on the surface of ocean – it beats through 18 m thick layer of water!

Discharge

Most likely, this is a first magnitude spring (1.) with an extremely powerful discharge that thus far has not been measured. Exact discharge of Crescent Beach Submarine Spring is not known but some assessments mention up to 40,000 l/s what would make it the most powerful spring in Florida and USA and… world? Some other sources modestly mention that this is “at least 2nd magnitude spring”…

Freshwater or – almost freshwater

Spring water is slightly saline (6 g/l) contrary to the surrounding seawater (35 g/l). The smell of hydrogen sulfide (old boiled eggs) can be felt near this place.

It has been observed that the power of the spring fluctuates – after heavy rain the spring is more powerful.

Geology

Crescent Beach Submarine Spring has formed in a location where the “cover” over the Floridian Aquifer – clay-rich Miocene and Plio-Pleistocene formations – has been eroded and the Eocene formation – Ocala Limestone is exposed.

Spring formed during the ice ages, when the level of ocean was lower and this land was above the sea level.

History

Crescent Beach Submarine Spring is known since at least 1875 when the U.S. Coastal Survey made the first bathymetric maps of the area. But there are stories that this location was used to get fresh water on ships long before this.

References

1. Re-examining the Submarine Spring at Crescent Beach, Florida. USGS Open-File Report 00-158, July 2000. Last accessed on 9th October 2023.
2. Crescent Beach Submarine Spring, St. Johns River Water Management District. Last accessed on 9th October 2023.
3. P.W Swarzenski, C.D Reich, R.M Spechler, J.L Kindinger, W.S Moore, Using multiple geochemical tracers to characterize the hydrogeology of the submarine spring off Crescent Beach, Florida, Chemical Geology, Volume 179, Issues 1–4, 1 September 2001, Pages 187-202. Last accessed on 9th October 2023.

Crescent Beach Submarine Spring is included in the following article:

Floridan Aquifer – source of giant springs

In the southern parts of South Carolina, Georgia and Alabama, as well as in most of Florida close to the ground surface is limestone that formed in Paleocene and Eocene.

In this area rain is frequent. Limestone is permeable – rainwater “soaks” into its fractures and pores, gradually dissolving the stone and creating passages through it (karst process). Such rainwater from the limestone is clean – it may be rich with lime but does not contain organic substances. It is very clear, with a distinct tint of blue-green color.

As a result, in these limestone layers has formed Floridan Aquifer – an extremely rich source of high quality groundwater.

In the central and northern parts of Florida, where this limestone is close to the ground surface, have formed hundreds of springs, including some of the most powerful springs in the world.

Springs and humans

These gargantuan fountains of lucid, blue-green masses of water attracted the attention of humans since the prehistoric times. More than 10 thousand years ago near the springs appeared some of the oldest settlements in this part of America – springs attracted enough fish and shellfish and people did not have to move around in eternal search of food.

Before the opening of Disney theme park the best known tourist attractions in Florida were several springs, such as Weeki Wachee Springs. Resorts were developed around numerous springs of Florida. Many of the great springs are very popular up to this day.

Unfortunately, human activities have left adverse impact on springs of Florida. Water uptake has decreased the flow rate in many springs. Most of the springs have been polluted to some extent. The most widespread is nitrate pollution that has been caused by the use of fertilizers in agriculture. Frequently the springs were degraded also by the recreational activities.

At the same time, there is done a lot to improve the environmental situation. One of the most important measures is the Florida State Rules “Outstanding Florida Springs” that establish specific rules for the groundwater use in areas around 30 most prominent springs.

About the list

The list below is based on a single parameter – the mean discharge of a single spring. If it exceeds 100 cubic feet (2,832 liters) per second – this is a spring of the first magnitude.

This might sound simple, but it is not. There are many pitfalls, such as:

• Many springs are rarely measured. Sometimes this is nearly impossible, for example, if the spring is on the riverbed. Should we really compare a spring that is measured a few times with a spring that has been measured for hundreds of times?
• The time period of measurements is not standardized. Should we take the mean discharge of one spring since the 1930ies and compare it with another one, whose measurements started only in 2000? This can be not fair, as the discharge of springs fluctuates a lot over the time. Thus, Hornsby Spring around 2008-2010 totally stopped to flow. But, in 2015-2023 its mean discharge has been 4 472 l/s – a true 1st magnitude spring!
• Is it one spring or more? Frequently this is hard to tell. Spring may come from a long fissure and in some places in the fissure the flow is weaker, in some – stronger. Is this one spring or numerous? There can be two vents just a few meters from each other – is this a single spring or two?
• Is river resurgence a true spring? In Florida this is a common feature – large rivers can disappear under the ground and then resurface again. This is not a “true” spring with clear, blue-green water – there comes up brownish, tannic river water. Wondermondo has included in this list river resurgences, but these are marked.
• Is karst window a spring? Frequently the ceiling of underground stream collapses and a short section of its stream opens to the outside world. Yes, at one end of it the water comes out as a spring, but at the other end this spring disappears underground again. In the list below are some karst windows, Wondermondo has marked them.

In spite of the above said, there certainly are true first magnitude springs. Currently there are 24 convincing 1st magnitude springs in Florida, but there are several more powerful springs that, upon more measurement and, also, in the case of better environmental policies, might be 1st magnitude springs.

Hornsby Spring is situated around 1 km from the Santa Fe River, in a swamp forest. This impressive spring has formed a 48 by 45 m large and up to 10.6 m deep spring pool (2.). The spring vent is located near the base of the underwater limestone ledge, which is situated on the northern side of the spring pool.

Hornsby Spring Cave System

Soon after its emergence, most of the spring water disappears underground again. It cascades through several swallets into the Hornsby Spring Cave System: a cave system that stretches for 5,876 meters and reaches depths of up to 46 meters. This cave system connects with the vent numbered ALA112971 in Treehouse Spring, which is approximately 1 km northwest, in Santa Fe River. At higher water levels, part of the stream flows above ground towards Treehouse Spring.

Fluctuations of the water flow

Hornsby Spring is one of 30 Outstanding Florida Springs. These are significant natural monuments that have individual planning and rules to maintain (six cleaner springs) or to improve (24 degraded springs, including Hornsby Spring) their environmental quality.

Similar to the nearby Treehouse Spring, Hornsby Spring lost much of its former power around 2006 – 2014, when its flow almost stopped. The mean discharge of the spring in a longer time period between 1998 and 2023 was 2 755 liters per second (1.), a bit short of 100 cubic feet or 2 832 l per second – threshold for 1st magnitude springs. But now it is a convincing 1st magnitude spring again: in 2015-2023 its mean discharge was 4 472 l/s!

Such fluctuations were not unique – also in 1998-2002 Hornsby Spring stopped its flow.

Water quality issues

But, in addition to the challenge of water amounts, there is also the challenge of pollution. Unfortunately, the water of Hornsby Spring is polluted with nitrates from agricultural runoff. This has led to algal growth – filamentous algae cover much of the limestone outcrop and create unpleasant algae mats floating in the spring pool. Removal of this pollution will require much effort and time.

Springs are located in a private area. Around them has been created Camp Kilaqua – a recreational area. Earlier the spring was the center of activities, but as it weakened and its pollution decreased its attraction, recreational activities have shifted away from the spring.

Prehistoric settlement

Paleoindians lived around the spring – such giant springs were a perfect place for settlement thanks to the abundance of top-quality drinking water (sea water was some 40 m below its present level and water was scarce), as well as food: shellfish, fish and land animals coming to the springs. Hornsby Spring was the first area in Florida where the settlement was radiocarbon dated in 1961. This data testified that people lived next to the spring 9,880 years ago (counting from 1961). Excavations took place earlier – in the early 1950ies.

References

1. Hornsby Spring. Suwannee River Water Management District, Water Data Portal. Last accessed on 29th September 2023.
2. First Magnitude Springs of Florida, Florida Geological Survey Open File Report No. 85. Last accessed on 29th September 2023.

A karst window at Natural Bridge of St. Marks River. Spring rises from the depth of some 9 m. The winding lake – a chasm in limestone cliffs – is some 410 m long and at its end the water goes into the underground again.

Some 330 m west from it is the sink of St Marks River, where it dives under the ground to reemerge some 950 m further south as St Marks River Rise. Also, the water, that is seen in the Natural Bridge Spring, goes towards the St Marks River Rise. Near the sink is also historic Natural Bridge Battlefield – a site of an important American Civil War battle.

References

1. Kris Barrios, St. Marks River and Wakulla River Springs Inventory
   Leon and Wakulla Counties, Florida, Northwest Florida Water Management District, July 2006. Accessed on September 13, 2023.

Alexander Spring is a beautiful spring with a large spring pool with dimensions of 91 by 79 meters, reaching a depth of up to 7.6 meters. The pool is filled with crystal clear, blue-green water. The spring is characterized by a group of closely located vents that create a visible boil on the surface from the bank. There is also a short underwater cave in the limestone wall at the vent, which is several meters long but diving into it is not allowed.

The water temperature remains constant at 22°C throughout the year, making it an excellent swimming spot for good swimmers due to its great depth. The limestone bedrock around the vent adds to the scenic beauty of the area.

Alexander Spring gives rise to Alexander Springs Creek, a river that spans between 15 to 40 meters in width. The creek flows through forests and marshes for approximately 16 kilometers before joining the St. Johns River.

The landscape surrounding Alexander Spring is idyllic, featuring subtropical forests with occasional cabbage palms and other trees. This spring stands out for its cleanliness, as it has low pollution levels compared to most other springs in Florida. Together with Silver Glen Springs, Alexander Spring is considered one of the cleanest springs in the state.

The area around Alexander Spring has been known since prehistoric times and holds cultural significance. The Timucuan people left behind a mound of shells and crayfish near the spring, which now serves as a picnic area. Similar to other large springs, Alexander Spring was a sacred place for local people before European colonization.

In summer 2023, an aggressive alligator was reported to be living in the spring. (2.)

References

1. Minimums Flow Determination for Alexander Springs, Lake Country, Florida, Bureau of Resource Evaluation and Modeling St. Johns River Water Management District, Palatka, Florida, 2017. Accessed on September 9, 2023.
2. Ethan Budowsky, Alexander Springs closed after second alligator incident in a week, WCJB.com, July 18, 2023. Accessed on September 27, 2023.

Alexander Spring is included in the following article:

Treehouse Spring is one of 30 Outstanding Florida Springs and one of six springs on this list that are considered to be not impaired, i.e., not significantly degraded by human activities. Nevertheless, the nitrate content in its water is slightly increasing.

This spring is located on the eastern bank of the Santa Fe River and has formed a bay-spring pool that is 38 by 53 meters large and up to 9.4 meters deep. The spring pool is a popular swimming location.

Two springs close together

This gargantuan spring has two vents: Treehouse Rise itself and a vent with the number ALA112971 a little south of the first. Surprisingly, even though both vents are located close to each other, each of them is connected to a different water passage.

The main vent connects the spring to the Old Bellamy Cave, a 12,657-meter-long and up to 48.77-meter-deep cave system. It goes up to another enormous river rise – Santa Fe River Rise.

ALA112971 is linked to another cave system – it is a resurgence from the Hornsby Spring, a kind of karst window approximately 1 kilometer away that disappears underground at Treehouse Swallet. The Hornsby Spring Cave System is a 5,876-meter-long cave system that is up to 46 meters deep.

Both Treehouse Spring and Hornsby Spring lost much of their power for some time period and even stopped flowing around 2012. However, lately, from 2015 to 2023, the spring has been very powerful, and since 2015 its mean output has been over 11,000 liters per second! (1.)

References

1. Treehouse Spring. Suwannee River Water Management District, Water Data Portal. Last accessed on 9th September 2023.
2. Treehouse Spring. Florida Springs.org. Last accessed on 26th September 2023.

Treehouse Spring is included in the following article:

Santa Fe Spring is a 2nd magnitude spring. Its mean output in the time period from 1997 to 2023 was 1 689 l/s. (1.) In general, the flow of this spring decreases due to the increased water extraction in the spring area.

Spring pond is 58.5 by 65.5 m large and up to 25.3 m deep (at higher water level). Banks of spring pond are high, forested and allow a fine view over the spring. This is one of the few large springs in this area that thus was was not transformed by recreational use.

This enormous spring pool was shaped by the power of water in earlier times, when Santa Fe Spring was more powerful. Now the spring flows in rainy periods and stops during the droughts. If there is a flood in the nearby Santa Fe River, the flow in the spring reverses. The spring water earlier was clean but now more frequently it is tannic, similar to a river water.

Spring water has a fairly high contamination with nitrates from the agricultural runoff.

Up to 46 m deep cave can be entered through the spring.

In 2019 a land plot with the springs was purchased by Alachua Conservation Trust and Santa Fe Springs Preserve was established around it. Gradually the natural ecosystem is reinstated in this area and tourist infrastructure developed. There are set also goals to increase the spring volume and improve its water quality.

References

1. Santa Fe Springs. Suwannee River Water Management District, Water Data Portal. Last accessed on 9th September 2023.
2. Two Freshwater Springs Permanently Protected by Alachua Conservation Trust. Alachua Conservation Trust. Last accessed on 25th September 2023.

The Santa Fe River, which is about 25 m wide, disappears underground in O’Leno State Park, at the Santa Fe River Sink. It meanders under the ground for several kilometers until it resurfaces at the Santa Fe River Rise, which is some 4.5 km in a straight line from the sink, in River Rise Preserve State Park.

The spring (resurgence) pool is 53 by 50 m large and up to 14.9 m deep. The average discharge from 1998 to 2014 was 14,511 l/s – in this respect, the Santa Fe River Rise is the third most powerful spring in Florida after Alapaha Rise (16,260 l/s) and Wakulla Spring (17,437 l/s).

This river rise may not be a true spring, but it is nevertheless a beautiful natural landmark. A natural forest extends between the river sink and its resurgence and also surrounds the rise.

An especially pleasant way to experience the beauty of this site is to travel by boat for several kilometers upstream from the High Springs Boat Ramp, passing by several more impressive springs.

While paddling above the River Rise, there is no sign of the powerful flow from the underground – the water is calm, like a lake.

This underground river has been carved in Ocala Limestone that formed in the late Eocene. The river and its underground section, however, are much younger.

Old Bellamy Cave

The spring run serves as one of the entrances to a large cave system – Old Bellamy Cave. The length of its explored passages is 12,657 m and its depth is 48.77 m. This cave was discovered in 1995 and is very dangerous for explorers.

History of Santa Fe River Rise

In prehistoric times, people used this area to mine chert – a valuable stone for weapons and other tools. There are four known prehistoric quarries in this area. The natural bridge between the sink and the River Rise (if we can call a 4.5 km wide section a “bridge”) has served as a transportation route since prehistoric times.

Near the sink, in the early 19th century, Old Bellamy Road was built and even a hotel (Leno Springs Hotel) was built near the sink. It burned down in 1896.

In 1934, the land around the sink was donated to the state and became one of the first Florida state parks.

Only in 1999, the land around the Santa Fe River Rise was acquired by the state and Florida established River Rise Preserve State Park.

Today, this is a charming natural forest area with numerous hiking trails and paddling areas.

References

1. SANTA FE RIVER AT RIVER RISE NEAR HIGH SPRINGS, Snoflo. Accessed on September 6, 2023.
2. Santa Fe River at River Rise. Suwannee River Water Management District, Water Data Portal. Last accessed on 9th September 2023.

Santa Fe River Rise is included in the following article:

Description

Manatee Spring is the most powerful spring flowing into the Suwannee River – and there is quite a competition, e.g. Lafayette Blue Spring, Fanning Spring and others.

The spring has formed in Ocala Group Limestone, Eocene. For most of the time, its beautiful spring pool is filled with clear, blue-green water that is discharged from the spring vent in incredible amounts.

The spring pool is 18 by 23 m large and up to 8 m deep. It is located in the forest near the Suwannee River and the spring water flows about 380 m through tidal hardwood forest towards the river. The spring run is about 20 – 40 m wide and, on average, 0.9 m deep.

The mean discharge of Manatee Spring from January 2001 to September 2023 has been 4,262 l/s, thus it is a convincing 1st magnitude spring.

This spring serves as a refuge for manatees, especially during the winter, when the constant spring water temperature (22.1 °C) is higher than the water temperature in the river.

The area around the spring pool has been modified by the infrastructure for visitors – walkways and stairs. This is one of the most frequently visited springs in Florida.

Manatee Spring is one of 30 Outstanding Florida Springs – especially interesting and beautiful springs with a specific set of rules for their protection.

Unfortunately, even if the spring water is clear, the pollution with nitrates from the agricultural runoff gradually increases in its water. This promotes the growth of filamentous algae in the spring pool and spring run.

Manatee Springs Cave System

The spring vent marks the start (or, rather, the end) of the Manatee Springs Cave System, a 7,125 m long and up to 29 m deep cave. This cave is a favourite destination for cave divers who, most often, enter the cave through another sinkhole nearby – Catfish Hotel.

Previously, a dive from Catfish Hotel towards Manatee Spring was popular. Now it is too dangerous due to the occasional extreme force of the current in conjunction with the collapse of the cave ceiling that has partly blocked the passage. This situation has led to the death of some cave divers.

When the nearby Suwannee River is flooded, the water flow can be reversed and the river water then enters inside the Manatee Springs Cave System. This natural process is important for the cave dwellers, such as Hobb’s cave amphipod, the pallid cave crayfish, and the swimming little cave isopod, because the floodwater brings new food for them.

History

Near the spring, there was a prehistoric human settlement by the Weedon Island Culture (1st millennium AD), but people used the spring for hunting long before this.

The spring was named by the explorer William Bartram (1739-1823) – the first researcher of Florida forests. He reached it in 1774 and was astonished by the unusual beauty of its blue-green water. He saw the carcass of a dead manatee at the shore of the spring and hence the spring got its name.

In 1949, Florida State acquired the land and in 1954, Manatee Springs State Park became the very first of the major Florida springs to be managed by the Florida Park Service (3.).

In 1971, the spring was designated a registered National Natural Landmark.

References

1. Manatee Spring NR Chiefland Fla – 02323566, USGS. Accessed on August 27, 2023.
2. Manatee Springs. Suwannee River Water Management District, Water Data Portal. Last accessed on 9th September 2023.
3. Summary of Existing Data –
   Manatee Springs (Levy Co.) (PDF file). Last accessed on 24th September 2023.

Manatee Spring is included in the following article:

It seems that lately the discharge of Madison Blue Spring has fallen slightly below the official threshold of the 1st magnitude springs. The mean discharge of a 1st magnitude spring should be at least 100 cubic feet or 2,832 litres per second. Measurements in Madison Blue Spring from 2002 to 2023 show a mean discharge of 2,763 l/s (97.6 cubic feet) (2.).

This does not diminish the popularity of this stunning natural wonder. The spring is situated in a very scenic area, and has formed a natural basin of incredibly clear, blue-green coloured water. The spring pool has a diameter of about 24.4 m and is up to 9.1 m deep. A limestone bluff is on its western bank.

The spring forms a pool that is connected to the nearby Withlacoochee River by a roughly 45 m long spring run with a lively stream in it. This short “river” is about 6 m wide and 1 m deep. The colour of the spring water contrasts with the tannic, brownish water of the river.

The spring has formed in Oligocene and Eocene limestone.

When there are floods in the Withlacoochee River, the water also rises in the spring pool – sometimes up to 6 metres! During the flood, the flow is reversed and slightly acidic river water enters underground. Throughout the millennia, this inflow of acidic water has created a large, impressive underwater cave system. Some 7.775 km of cave passages have been explored through the vent of the spring. The depth of the cave reaches 43 m.

Madison Blue Spring is included in the list of Outstanding Florida Springs, along with 29 other springs of the state. Around the spring, Madison Blue Spring State Park has been created – it was established in 2000 after the sale of this formerly private land to the state. This is a well-known site for cave divers, but also used for swimming, tubing, paddling. The water temperature in the spring is constant – 21.3 ° C.

Unfortunately, the nitrate pollution in the water of the spring has gradually increased (3.).

References

1. Madison Blue Springs Named America’s Best Swimming Hole, USA Today, July 24, 2015. Accessed on September 24, 2023.
2. Madison Blue Spring, Florida Springs. Accessed on August 20, 2023.
3. Summary of Existing Data –
   Madison Blue Spring (Madison Co.) (PDF file). Accessed on August 26, 2023.
4. Madison Blue Spring NR Blue Springs, FL – 02319302, USGS. Accessed on August 27, 2023.
5. Madison Blue Spring. Suwannee River Water Management District, Water Data Portal. Last accessed on 9th September 2023.