The Native-American name for Lake Jackson, located near Tallahassee, Florida, is Lake Okeeheebee, meaning disappearing waters. Local authorities should have kept the original name because there is another Lake Jackson in central Florida, and there is also a Lake Jackson in nearby Georgia. The existence of multiple Lake Jacksons in this region made researching this blog article confusing. I wonder what Native-Americans thought the reason was for the periodic draining of this lake. They probably invented some kind of mythical story. Modern geologists know the cause for the periodic disappearance of this lake. The lake sits on karst terrain where sandy soils prevail. Karst terrain consists of unevenly eroding limestone. Slightly acidic rain causes bedrock to erode, resulting in many underground caverns that often collapse into sinkholes. There are 2 sinkholes underneath Lake Jackson–the Porthole Sink and the Lime Sink. During dry spells when the water table falls, water from Lake Jackson drains into these sinkholes, just like water draining from a bathtub. Plant debris and mud will temporarily block the sinkholes, but eventually most of the lake will drain with the exception of small pools here and there where fish populations survive. The permeable sandy soils allow water to refill the lake following periods of higher rainfall that cause the local water table to rise.
Lake Jackson is 6.2 square miles and averages 6 feet deep when it is full of water, though it is as much as 28 feet deep over the sinkholes. The lake has drained 14 times over the past 200 years, and it is currently in a drained stage. Surprisingly, periodic drainages are good for fishing. The draining reduces populations of the non-native plant hydrilla, and the re-filling stirs up nutrients, increasing food for rebounding fish numbers. Fishermen claim the fishing for largemouth bass, crappie, bluegill and redear sunfish, and bullhead catfish is excellent. The latter species is especially well-adapted for surviving in small pools during drainage phases. Though not mentioned on the internet, I’m sure bowfin, gar, and non-native tilapia thrive as well. Birdwatchers report the presence of herons, egrets, limpkins, eagles, ospreys, ducks, geese, fish crows, and least terns. It’s good habitat for alligators, turtles, and frogs too.
The karst terrain makes it difficult for rivers to flow in this region, and there are 2 rivers that vanish here. The Alapaha River, a tributary of the Suwannee River, simply disappears into the ground, flowing right into a sinkhole, and it emerges miles away. The Santa Fe River also disappears into a sinkhole, also to emerge miles away. Both become subterranean during part of their course. A river flowing into the ground is known as a swallet.
Reference:
Bryan, J., Scott, T., Means, Guy
Roadside Geology of Florida
Mountain Press Publishing Company 2008
Tags: Karst terrain, Lake Jackson, Lake Okeeheebee, lakes and rivers that vanish, sinkholes
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