Two Great Swamps, PART TWO WWFF-14

The smaller, but still important brother of the Everglades is the Central Florida- Green Swamp Hydrologic  System. It is, in effect, the reverse of the ‘glades.  The Everglades water starts in rivers, and ends up in a swamp. The Green Swamp water falls in a swamp and flows into rivers.

 Under Polk, Lake, Sumter, Hernando and Pasco Counties is a unique raised plateau of limestone that shallowly underlies the surface. The groundwater system called the Floridian Aquifer follows the contour of this limestone. The proximity of the aquifer to the surface allows it to recharge easily from rainfall.

Rainfall during the summer in Florida falls from storms formed on sea-breeze fronts. Those fronts form near the coasts and move inland. Here, in the center of Florida either the East Coast Sea-breeze rain front, or the West Coast Sea-breeze rain front drop rain daily. If there is no prevailing wind, both rain fronts might make it over this area. There are also tropical flooding events from tropical storms and Hurricanes that sporadically dump rain in the recharge area.  

 The Green Swamp wetland system covers about 900 square miles and includes the headwaters of the Hillsborough, Withlacoochee, Little Withlacoochee, Ocklawaha and Peace Rivers.  The Green Swamp is second only to the Florida Everglades in terms of hydrologic and environmental significance to the state.

This area is the highest elevation of Floridian Aquifer limestone in peninsula Florida, and like a water tower, it sits high above the rest of the aquifer.   Gravity causes pressurization of the waters trapped in the limestone, causing freshwater springs to flow up to the surface hundreds of miles away from the swamp. This large volume of porous limestone easily allows water to flow into, and within, the rock like a pipe.

That makes it like a big pipe connected to a big tank; and during the rainy season it is always being topped off by rain. With their soft sand and peat built up from centuries of plant detritus, the floodplain forests and swamps promote natural retention of flood waters. The slow moving water at the same time provides habitat for many plant and wildlife species. The surface waters move through lazy, winding riparian forest lined rivers that are only completely full during tropical flooding events. 

Both of these great swamps are as similar as they are different. There are huge, but the Green Swamp is but one tenth the area of the Everglades. They gather rain and ever so slowly transport it under, around, and between the wild benefactors of the system. The Green Swamp turns into four rivers and thousands of springs. The Everglades begins in springs and rivers and becomes a swamp.  Both recharge and get recharged by an aquifer. The rivers of the Green Swamp run north, west, east, and south. The Everglades runs southwest from the great lake until it loses its identity in the Gulf of Mexico. The Green Swamp’s rivers drain into both the Gulf and the Atlantic Ocean. They are a great study in comparison and contrast hidden into Florida’s two great swamps.