Florida Water Science Center
The FLORIDAN PAGES
Floridan Aquifer System Groundwater Availability Study
The Floridan aquifer system covers approximately 100,000 square miles in the southeastern United States in Florida and portions of Georgia, Alabama, Mississippi, and South Carolina. It is a sequence of carbonate rocks over 3000 feet thick in south Florida and thins towards the north. Typically split into the Upper Floridan aquifer, the middle confining unit, and the Lower Floridan aquifer, the majority of freshwater is contained in the Upper Floridan aquifer and is used for water supply (Miller, 1986, 1997). The Lower Floridan aquifer contains fresh to brackish water in northeastern Florida and Georgia, while in south Florida it is saline and used to dispose of effluent from wastewater treatment processes.
Precipitation in the southeastern United States is around 53 in/year. The majority of recharge to the Floridan aquifer system occurs in the areas where it is unconfined or semi-confined, approximately 10-25 in/year, whereas in the areas of confinement the recharge is less than 1 in/year (Bush and Johnston, 1988; Sepulveda, 2002). Natural discharge to streams and lakes occurs through springs or to the ocean through submarine groundwater discharge (Stewart, 1980). Florida alone has 33 springs that discharge more than 64.6 million gallons per day per spring (Spechler and Schiffer, 1995).
Groundwater wells for water supply from the Floridan aquifer system were first drilled in the late 1800's. Currently, the Floridan aquifer system supports almost 10 million people as their primary source of water and is one of the most productive aquifers in the world (Marella and Berndt, 2005; Miller, 1990). Water from the Floridan aquifer system is used for public, domestic, and industrial water supply, with almost 50% of water being used for irrigation.