Georgia Water Science Center Publications
Hydraulic characteristics of the upper Floridan aquifer in the Savannah and St Marys areas of coastal Georgia
Georgia Geologic Survey Information Circular 105, 23 pages
Debbie Warner and Brent T. Aulenbach, U.S. Geological Survey
Hydraulic characteristics (transmissivity and storage coefficient) of the Upper Floridan aquifer in the Savannah and St Marys areas of coastal Georgia were evaluated by analyzing results of water-level recovery tests. Tidal corrections were applied to data from one well for the Savannah area test, and to data from the four wells for the St Marys area test. Data from one well used in the St Marys area test also were corrected for effects of nearby pumpage. Transmissivity tensor analyses were conducted to evaluate the anisotropy of the aquifer at the Savannah and St Marys test sites.
For the Savannah area, calculated transmissivity of the Upper Floridan
aquifer ranges from 32,000 to 43,000 feet squared per day, and the storage
coefficient ranges from 6.3 x 10-4 to 1.3 x 10-3. Transmissivity of the
aquifer has an anisotropy ratio of approximately 1.2:1 and an angle of
anisotropy of approximately 108 degrees (measured counterclockwise from due
east). Thus, the larger principal value of transmissivity is aligned
approximately in the direction of north-northwest.
For the St Marys area, calculated transmissivity of the Upper Floridan
aquifer ranges from 98,000 to 170,000 feet squared per day, and the storage
coefficient ranges from 9.9 x 10-4 to 2.4 x 10-3. Transmissivity of the
aquifer has an anisotropy ratio of approximately 2.5:1 and an angle of
anisotropy of approximately 64 degrees (measured counterclockwise from due
east). The larger principal value of transmissivity is aligned
approximately in the north-northeast direction.
TABLE OF CONTENTS
Purpose and scope
General hydrogeology of the Georgia coastal area
Hydraulic characteristics of the Upper Floridan aquifer
Savannah area aquifer test
St Marys area aquifer test
Comparison of aquifer-test results
Appendix--Technique for removing effects of tides and pumpage from ground-water levels measured during an aquifer-recovery test at St Marys, Georgia
Regression technique for removing tidal and pumping effects
Results and discussion
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