Florida springs are ‘bowls of liquid light’

After our week of biking in Florida, we took off for a different adventure: kayaking the rivers and springs around Gainesville.

This was another Road Scholar program, so we didn’t have to take our own kayaks, and as well as being fun, it was very educational. After arriving at our accommodations for the week we saw a documentary on the springs in Florida. On the first full day of the program, we visited the Howard T. Odum Florida Springs Institute in High Springs, Florida, for a discussion of the problems facing the Floridan aquifer which covers approximately 100,000 square miles of the southeastern United States. This system is one of the most productive aquifers in the world and is the primary source of drinking water for almost 10 million people, with nearly 50% of all water withdrawals being used for industrial purposes and agricultural irrigation. The institute was founded in 2010 as a non-profit and is not related to any university or governmental agency so that it can retain its neutrality and report the science without bias or political pressure. They also have a citizen science program called Springswatch, which is very similar to our Hoosier Riverwatch.

Northern Florida has many springs due to the Cody Escarpment, located through the north and central parts of Florida. It roughly approximates an ancient shoreline of Florida when sea levels were much higher. Above the escarpment the bedrock is covered by clay, but below it the clay was eroded away and exposed the porous limestone (ancient reefs) below.

Every river that crosses this escarpment in the Suwannee River Management District goes underground and reemerges downstream as a spring, with the sole exception of the Suwannee River. A prime example of this is the Santa Fe River. At O’Leno State Park the entire Santa Fe River is swallowed up by a sink (an area where the limestone has weakened and collapsed, resulting in the water dropping out of sight) as the river crosses the escarpment. It then travels underground through a network of cave passages for over three miles before re-emerging at a spring in River Rise Preserve State Park. (Source: Suwannee River Management District)

After visiting the institute, we kayaked on the Ichetucknee River, which rises from the Blue Hole and flows into the Santa Fe and ultimately into the Suwannee River. The highlight of the paddle was seeing manatees alongside our kayaks, particularly a mother with a calf. We were also entertained by two swallow tailed kites that flew loops overhead as we paddled along, as well as great egrets, blue herons, snowy egrets and a pileated woodpecker.

Springs were described as “bowls of liquid light” by environmentalist Marjorie Stoneman Douglas, and 18th-century explorer William Bartram called them “enchanting and amazing crystal fountains.” Both descriptions are accurate.

The second day we kayaked along the Santa Fe River, which is considered a black river due to the high amount of tannin occurring naturally in the water from the surrounding plants, and the bottom was invisible at depths of greater than a foot or so. But when we entered the Gilchrist Blue Spring area the water was crystal clear and the bottom easily visible at depths of 10 feet or more.

The only disappointment of the week was that the last day when we were supposed to kayak on the Silver River into Silver Springs, the weather didn’t cooperate: lots of rain and thunder and lightning. We had good rain gear, but the lightning caused the excursion to be canceled.

There is concern about the health of the springs and the entire Floridan aquifer. The two biggest concerns are (1) the increased level of nitrates from agricultural and residential runoff and (2) currently more water is being pumped out of the springs than is being replaced by rainfall, despite Florida’s frequent rains. A very valid point made in the documentary was that even though agricultural usage is responsible for a lot of the nitrates, farmers are not the enemy but must be considered as partners in finding the solution to this problem. It was also emphasized that clear water is not necessarily clean water, as nitrates are not visible in water.

Another part of the documentary that was interesting was scenes of divers exploring the underground labyrinth of the springs and the aquifer. The limestone karst region (we have a limestone karst region in southern Indiana, too) has been described as a giant sponge that takes in the ground water, runs it through channels and caves and then offers it up again to the surface. These channels and caves were mostly unknown until 20 years ago when technology allowed divers to map them.

When a spring dries up, as is happening more frequently with the increased need for water, it becomes a sink. Naturally occurring sinks were frequently seen as “dumps” (much like wetlands in more northern climes), and divers found oil drums, old tires, containers of antifreeze and roofing tar, and other polluting items as they traveled underground. Water flows, and divers found these items often quite a distance from where they were originally dumped. Scientists on the surface were tracking the divers underground through radio technology and their path was eye-opening. The trackers followed the divers through fields and forests, as well as a bowling alley and a restaurant! We need to be aware of what is below us, as well as around us!

We all need to be aware of the problems facing our aquifers and become advocates for good water management.

Elma Chapman is an Indiana Master Naturalist who lives in Middlebury. She can be contacted at chapman_ej@yahoo.com.