Potentiometric Map (PotMap)
Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida
Abstract
Potentiometric surface maps of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity are published semi-annually as part of a cooperative agreement between the U.S. Geological Survey, St. Johns River Water Management District, South Florida Water Management District, and the Southwest Florida Water Management District. Potentiometric contours are based on water-level measurements collected each May and September at over 550 wells, near the end of the dry and wet seasons, respectively. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.
Archived PotMap Data Files:
Each file contains contour shapefiles, water-level elevations, and a .pdf file of the published map. Individual map layers are not included. Formats from map-to-map may be slightly different as methods evolved.
September 2006 – Present
- Maps contain all relevant Metadata.
September 2007
May 2007
September 2006
May 2000 – May 2006
- Some of the early maps may not have complete attribute tables.
- All contours are projected as geographic NAD27, decimal degrees.
- All water-level elevations reference the NGVD29 datum.
May 2006
September 2005
May 2005
September 2004
May 2004
September 2003
May 2003
September 2002
May 2002
September 2001
May 2001
May 2000
September 2000
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