The Floridan aquifer system (FAS) is one of the most productive aquifers in the world. It underlies an area of approximately 100,000 square miles beneath all of Florida and parts of southeastern Georgia, Alabama, and South Carolina.
The Floridan aquifer system (FAS) is a sequence of Tertiary carbonate rocks that generally thickens seaward from the northern boundary of the system.The total thickness of the carbonate rocks ranges from approximately 100 feet at the updip limit to over 3,300 feet. Over roughly half of its extent, the FAS is an unconfined to thinly confined karst aquifer. Where the system is confined it is overlain by a very leaky upper confining unit and the Surficial aquifer system. The upper confining unit consists of several hundred feet of low-permeability clastic sediments and fine-grained lower-permeability limestone. At a regional scale, permeable rocks in the upper and lower parts of the FAS are grouped into the Upper and Lower Floridan aquifers units, respectively. The Upper and Lower Floridan aquifer units are separated by either the Bucatunna clay confining unit, the Lisbon-Avon Park composite unit, or the Middle Avon Park composite unit depending on location. The FAS behaves as one aquifer over much of its extent, though rocks of the confining and composite units create hydrologic separation between the Upper Floridan and Lower Floridan sub-regionally.
A updated hydrogeologic framework is published in Revised hydrogeologic framework of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina (USGS Professional Paper 1807). The revised framework is a regional work product intended for regional and subregional investigations (1,000 to greater than 10,000 square miles), rather than site-scale (less than 1 square mile) investigations intended for regulatory purposes. This report describes in detail the revised mapping of the system. The companion report for Professional Paper 1807, Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina (USGS Data Series 926), fully documents all of the spatial datasets supplemental to the framework of this karst system, including locations and historic magnitude of springs. Tabulated Transmissivity and Storage Properties of the Floridan Aquifer System in Florida and Parts of Georgia, South Carolina, and Alabama (USGS Data Series 669) provides a database of all furnished aquifer test records and results of USGS aquifer test compiled from multiple State, Federal, and local agencies. Transmissivity of the upper Floridan aquifer in Florida and parts of Georgia, South Carolina, and Alabama (USGS Scientific Investigation Map 3204) provides a transmissivity map of the FAS.
All hydrogeologic framework data layers and additional data described in Professional Paper 1807 and Data Series 926 can be downloaded from the USGS Publications Warehouse as either a geodatabase, shapefiles, or ASCII grids. For information about the available file types, see Aquifer data: Explanation of spatial data formats.
The metadata files listed below represent a subset of the spatial datasets documented in these reports.
Borehole Data:
- Surficial Aquifer System (thickness) Metadata
- Upper Confining Unit (thickness) Metadata
- Floridan Aquifer System (top) Metadata
- Floridan Aquifer System (base) Metadata
Hydrogeologic Unit Extents:
Hydrogeologic Unit Altitude (Contour Lines):
- Surficial Aquifer System - Not Available
- Upper Confining Unit - Not Available
- Floridan Aquifer System (top, 20 foot contour interval) Metadata
- Floridan Aquifer System (top, 50 foot contour interval) Metadata
- Lower Floridan Aquifer (top) Metadata
- Floridan Aquifer System (base) Metadata
Hydrogeologic Unit Altitude (Continuous Surfaces):
- Surficial Aquifer System - Not Available
- Upper Confining Unit - Not Available
- Floridan Aquifer System (top) Metadata
- Floridan Aquifer System (base) Metadata
Hydrogeologic Unit Thickness (Contour Lines):
Hydrogeologic Unit Thickness (Continuous Surfaces):
Below are other webpages associated with this aquifer.
Principal Aquifers of the United States
Regional Groundwater Availability Studies
- Overview
The Floridan aquifer system (FAS) is one of the most productive aquifers in the world. It underlies an area of approximately 100,000 square miles beneath all of Florida and parts of southeastern Georgia, Alabama, and South Carolina.
Sources/Usage: Public Domain.The Floridan aquifer system (FAS) is a sequence of Tertiary carbonate rocks that generally thickens seaward from the northern boundary of the system.The total thickness of the carbonate rocks ranges from approximately 100 feet at the updip limit to over 3,300 feet. Over roughly half of its extent, the FAS is an unconfined to thinly confined karst aquifer. Where the system is confined it is overlain by a very leaky upper confining unit and the Surficial aquifer system. The upper confining unit consists of several hundred feet of low-permeability clastic sediments and fine-grained lower-permeability limestone. At a regional scale, permeable rocks in the upper and lower parts of the FAS are grouped into the Upper and Lower Floridan aquifers units, respectively. The Upper and Lower Floridan aquifer units are separated by either the Bucatunna clay confining unit, the Lisbon-Avon Park composite unit, or the Middle Avon Park composite unit depending on location. The FAS behaves as one aquifer over much of its extent, though rocks of the confining and composite units create hydrologic separation between the Upper Floridan and Lower Floridan sub-regionally.
A updated hydrogeologic framework is published in Revised hydrogeologic framework of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina (USGS Professional Paper 1807). The revised framework is a regional work product intended for regional and subregional investigations (1,000 to greater than 10,000 square miles), rather than site-scale (less than 1 square mile) investigations intended for regulatory purposes. This report describes in detail the revised mapping of the system. The companion report for Professional Paper 1807, Digital surfaces and thicknesses of selected hydrogeologic units of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina (USGS Data Series 926), fully documents all of the spatial datasets supplemental to the framework of this karst system, including locations and historic magnitude of springs. Tabulated Transmissivity and Storage Properties of the Floridan Aquifer System in Florida and Parts of Georgia, South Carolina, and Alabama (USGS Data Series 669) provides a database of all furnished aquifer test records and results of USGS aquifer test compiled from multiple State, Federal, and local agencies. Transmissivity of the upper Floridan aquifer in Florida and parts of Georgia, South Carolina, and Alabama (USGS Scientific Investigation Map 3204) provides a transmissivity map of the FAS.
All hydrogeologic framework data layers and additional data described in Professional Paper 1807 and Data Series 926 can be downloaded from the USGS Publications Warehouse as either a geodatabase, shapefiles, or ASCII grids. For information about the available file types, see Aquifer data: Explanation of spatial data formats.
The metadata files listed below represent a subset of the spatial datasets documented in these reports.
Borehole Data:
- Surficial Aquifer System (thickness) Metadata
- Upper Confining Unit (thickness) Metadata
- Floridan Aquifer System (top) Metadata
- Floridan Aquifer System (base) Metadata
Hydrogeologic Unit Extents:
Hydrogeologic Unit Altitude (Contour Lines):
- Surficial Aquifer System - Not Available
- Upper Confining Unit - Not Available
- Floridan Aquifer System (top, 20 foot contour interval) Metadata
- Floridan Aquifer System (top, 50 foot contour interval) Metadata
- Lower Floridan Aquifer (top) Metadata
- Floridan Aquifer System (base) Metadata
Hydrogeologic Unit Altitude (Continuous Surfaces):
- Surficial Aquifer System - Not Available
- Upper Confining Unit - Not Available
- Floridan Aquifer System (top) Metadata
- Floridan Aquifer System (base) Metadata
Hydrogeologic Unit Thickness (Contour Lines):
Hydrogeologic Unit Thickness (Continuous Surfaces):
- Science
Below are other webpages associated with this aquifer.
Principal Aquifers of the United States
This website compiles USGS resources and data related to principal aquifers including Aquifer Basics, principal aquifers maps and GIS data, and the National Aquifer Code Reference List.Regional Groundwater Availability Studies
Regional groundwater availability studies enable information about groundwater to be integrated and consistent, so that this resource can be analyzed and understood on an aquifer–wide scale. These studies provide decision–makers with a better understanding of the status and trends in the Nation's groundwater availability. - Publications