Thrust Areas Ecosystem Water Institute Classification Level
Water, Land Use and Ecosystems Water and Climate Water and Society Water Resources Sustainability Springs Wetlands Watersheds Aquifers Lakes Coastal Zone  Water Institute Classification 1  Water Institute Classification 2  Water Institute Classification 3  Water Institute Classification 4
Ecosystem: Aquifers

Aquifers are underground porous rocks that hold water and allow water to move horizontally through holes in the rock. Where water in an aquifer is confined by an overlying impermeable layer, pressure forces water to rise to the land surface, creating natural freshwater springs. Aquifers in Florida typically contain a freshwater layer above heavier salt water. Saltwater intrusion in the upper aquifer can occur when wells are drilled too deep, too much freshwater is pumped from the aquifer, or due to sea-level rise. Aquifers are replenished by rainfall seeping vertically through overlying soils. Aquifers provide the vast majority of human water supplies in Florida. Issues in aquifer management include contamination, depletion due to over-pumping, saltwater intrusion, aquifer storage and recovery, and fracking.

There are five major aquifers in Florida. The Floridan aquifer, a primary source of water for human use in Florida and the source of most springs, is comprised of limestone and dolomite that thicken to about 3000 feet in south Florida. The Floridan aquifer is one of the highest producing aquifers in the world. Some of the deeper water in the Florida aquifer has been there for 26,000 years. The sand and gravel aquifer, the primary source of water in the Florida panhandle, consists of sand and gravel with interbedded layers of silt and clay. The Biscayne aquifer, the primary source of water in southeast Florida, consists of highly permeable limestone and less permeable sand and sandstone. Water from the Biscayne aquifer is pumped to the Florida Keys. The surficial aquifer, used for domestic, commercial, and small municipal supplies, includes other undefined aquifers present at land surface in Florida. The surficial aquifer generally consists of unconsolidated sand, shelly sand, and shell. The intermediate aquifer system, the main source of water in southwest Florida, lies between the surficial and Florida aquifers and consists of permeable layers of sand, shell and limestone separated by clay.

Aquifers Projects