The state of Florida has many forms of “naturally” clean, refreshing and exciting fun for all who seek. Some of the best destinations in Florida are freshwater places like cool, clear rivers and springs. The springs are especially interesting and many of Florida’s visitors flock to these extraordinary natural wonders (1). More than $500 million is pumped into Florida’s economy each year from state-owned freshwater aquatic sites.
Central Florida springs come in many shapes, sizes, and magnitudes. Some springs are artesian in nature, flowing millions of gallons per minute, some springs gushing slowly between toes in the sand, while others are completely underground and never seen. Many of these springs are hidden from view, throughout central Florida, while others are in plain sight.
Virtually all of these springs are pure, clear, clean and impressive, with a constant temperature of around 72 degrees. (1) Many of the springs I speak of are undiscovered treasures, hidden by dense forests, mostly pristine or state-owned areas left in natural settings. Florida purchases large parcels for their strategic location, such as natural watersheds, springs, lakes, rivers, and other highly critical ecosystems responsible for Florida’s freshwater sources. Many of Florida’s springs are owned by private citizens as well as industry.
Central Florida’s springs, rivers, lakes, ponds, and the like are supplied by aquifer water stored in Central Florida’s land as underground water tables, or “aquifer systems.” Many call aquifer systems groundwater rivers because the water within aquifer systems can move at considerable flow rate, much like a river.
Aquifers can be thought of as vast caverns of permeable rock, which “hold” water and create hydrogeological movement through holes within the rock due to naturally developed “head” pressures. (3) Aquifers can form from different types of earth materials, such as sands, clays, shells, limestone, and karst.
Interestingly, water can be trapped in these aquifer systems for years before rising to the surface and flowing out of a spring. Natural springs give us insight into aquifer systems and how they can appear underground as well.
Some of Florida’s rivers disappear entirely only to emerge again downstream. This can happen when a sinkhole develops in a riverbed. The river can be swallowed whole, without any sign that it ever existed. (2) Then, just as suddenly as it disappeared, it reappears and continues to flow on the surface. The Santa Fe River in North Florida is a great example of a disappearing river. This particular river empties into a large sinkhole in O’Leno State Park and reappears nearby in the River Rise Preserve State Park.
Sinholes of Florida
The type of landscape we are discussing is excellent for natural springs and aquifer systems to form. However, sinkholes are also a common natural occurrence due to the Central Florida landscape. The land surface of central Florida can suddenly open up like a sinkhole and swallow whatever is on top of it. Sinkholes occur naturally in central Florida, but recently, their frequency has increased.
Unfortunately, when sinkholes develop suddenly, loss of property and life can occur. A sinkhole opened in a residential area of Seffner, Florida, where a man sleeping in his house was swallowed by the sinkhole and was never found. Sinholes can form when the land collapses due to weather patterns that cause too much or too little rain. Over-pumping of Florida’s groundwater resources can also lead to the formation of sinkholes.
Florida Karst Landscape
Florida’s karst subsurface rock is relatively brittle and does not support compressive loads well. The incompressible water contained in underground aquifer systems acts as a solid to support surface soils. When hydrogeologic pressure is released for whatever reason, sinkholes can and do occur suddenly. Karst rock landscapes are notorious for forming sinkholes, and the Florida karst landscape is no exception. (two)
These underground cavities and conduits are important elements in one of the most productive freshwater sources in the world; the Floridan Aquifer, which underlies the entire state and extends under parts of Mississippi, Alabama, Georgia, and South Carolina. That is, contaminants enter the aquifer system and can travel long distances quickly. The Department of Environmental Protection (DEP) confirmed this fact by injecting dye into Florida’s underground waterways and waiting for it to reappear downstream. In most cases, DEP found the dye far from its source where it appeared in the waterways in question.
The unique karst landscape, as you can see, “hides” much of Florida’s rainwater by absorbing it into the ground and containing it in naturally functioning caves, aquifers and springs. If one can imagine, the karst surface of central Florida “floats” in a bubble of fresh water called the Florida Aquifer System.
Reference
1. Cool Escapes: Florida’s Refreshing Springs | Florida rambler.
2. Santa Fe River (Florida). Wikipedia
3. University of Florida, UF Research: Underground Rivers, Springs
