C\1 C\1 POTENTIOMETRIC SURFACE OF THE UPPER CJ) ::s FLORIDAN IN GEORGIA AND ADJACENT PARTS t;;: OF ALABAMA, FLORIDA, AND SOUTH CAROLINA, MAY 1998, () ' (!) AND WATER-LEVEL TRENDS IN GEORGIA, 1990-98 0 ....J by 0 a: Michael F. Peck\ JohnS. Clarke1, Camille Ransom, IIF, and Christopher J. Richards3 0 I U.S. Geological Survey 2South Carolina Department of Health and Environmental Control 3Northwest Florida Water Management District >­ I

Prepared in cooperation with the U.S. DEPARTMENT OF THE INTERIOR U.S. Geological Survey

GEORGIA DEPARTMENT OF NATURAL RESOURCES Lonice C. Barrett, Commissioner

ENVIRONMENTAL PROTECTION DIVISION Harold F. Reheis, Director

GEORGIA GEOLOGIC SURVEY William H. Mclemore, State Geologist

ATLANTA 1999 HYDROLOGIC ATLAS 22

The Department of Natural Resources is an equal-opportunity employer and offers all persons the opportunity to compete and participate in each area of DNR employment regardless of race, color, religion, sex, national origin, age, handicap, or other non-merit factors. 1-'repared m cooperation with the Hydrologic Adas 22 !::NV IKON MENTAL PRUfECTION DIVISION U.S: DEPARTMENT OF THE INTERIOR Peck, M.F. , ~L.al., 1999, Potentio metric surface of th~ Upper Aoridan aquifer in Georgia and adjacent parts GEORGIA GEOWGIC SURVEY U.S. GEOlDGICAL SURVEY ol Alabama, Flori&., and South Caroli na, May 1998, and water-level trends in Georgia, 1990- 9 8

INTRODUCTION Ron Ceryak of the Suwannee River Water Management D istrict; Larry Fayard of the Southwestern are a North-Centra l area generally rose during the period May 1990 to May 1998, corresponding to decreased SELECTED REFERENCES St. Johns Water Management District; and Denny Moore and Blakeney Gillett of the The Upper Floridan aquifer is part of the Floridan aquifer system that underlies most of The Upper Fl.oridan aquifer in the southwestern area is exposed or overlain by sandy clay In the north-central area, the configuration of the potentiometric surface is influenced pumpage from the Upper Floridan aquifer. Pumpage decreased from about 88 Mgal/d Clarke, J.S., 1987, Potentiometric surface of the Upper Floridan aquifer in Georgia, May 1985, and water­ Alabama Geological Survey for their assistance in the collection and tabulation of level trends, 1980-85: Georgia Geologic Survey Hydrologic Atlas 16, scale I: 1,000, {}(]0, 1 sheet. the Coastal Plain of Georgia, southern South Carolina, extreme southeastern Alabama, regolith that is hydraulically connected to streams. This connection is evident on tl1c by surface topography and streams because of the shallow depth of the Upper Floridan in 1990 (Fanning, 1992), to 76 Mgalid in 1997 (Fanning, !999). The overall water­ ground-water data used in this report. Clurke, J.S., and West, C.T., 1997, Ground-water levels, prcdc-.clopment ground-water flow, and stream­ and all of Florida (Miller, 1986). The aqu.ifer system is one of the most productive in potentiometric surface where the contours cross the Flint River and bend upstream, an aquifer and the thin or absent confining unit. Stream interaction is indicated by poten­ level rise due to reduction in industrial pump age during 1990---98 is illustrated by the aquifer relations in th e vicinity of" the Savannah River Site, Georgi<~ ami South Carolina: U.S. Geological indication that brround water discharges to the river. To the southeast in the area of Worth tiometric contours that cross the Ocmulgee, Oconee, and Ogeechee Rivers and bend hydrograph for 36Q008; this well is located near the center of pumping in the the United States ami a major source of water in the region. Approximately 700 million Survey Water-Resources Investigations Repon 97-4197, 120 p. gallons per day (Mgal/d) of water was withdrawn from the Floridan aquifer system POTENTIOMETRIC SURFACE AND WATER-LEVEL TRENDS and Mitchell Counties, the potentiometric contours are more closely spaced, and the upstream. Steep topographic relief, particularly near the Savannah River valley, causes a Savannah area. __ 1998, Simulation of ground-water flow and stream-aquifer relations in Georgia and South Carolina, during 1995 in Georgia. Most of this water was withdrawn from the Upper Floridan The configuration of a potentiometric surface indicates general directions of b,rround­ hydraulic gradient is steep because of the lower permeability sediments of the Gulf steep hydraulic gradient between topographic highs (recharge areas) and stream valleys predevelopment through 1992: U.S. Geologictd Survey Water-Resources Investigations Report 98-4062, Jesup-Doctortown area aquifer mainly for industrial and purposes {Fanning, 1997). To monitor water flow and areas of recharge (highest water levels) and discharge (lowest water Trough. Water levels in the southwestern area generally were higher in May 1998 than in (di scharge areas) (Clarke and West, 1997). In the southeastern part of tl10 north-central 134 p. In the Jesup-Doctortown area, a cone of depression has developed mainly as a result seasonal and long-tenn water-level fluctuations and trends in the Upper Floridan and levels). Water infiltrating an aquifer flows from recharge areas to discharge areas. The May 1990; however, water levels in south-central Worth County declined about 2 to 5 ft, area, the lower permeability sediments of the Gulf Trough result in a steep potentiometric Fanning, J.L. , 1992, Water use in Georgia by county: Georgia Geologic Survey Information Circu lar 90, other in Georgia, the U.S. Geological Survey {USGS), in cooperation with the Coastal Plain of Georgia has been informally divided into four subareas for discussion and in Early, Miller, and Baker Counties declined about l to 19ft. gradient between the 70- and 120-ft contours. Water levels in the north-central area of industrial pumping. ln 1998, the water level near the center of the cone was about 98 p. 45ft. Water levels in the Jesup-Doctortown area generally rose during the period Georgia Department of Natural Resources Environmental Protection Division, Georgia of the contiguration of the potentiometric sutface and water-level trends; these are the Water-level fluctuations in the southwestern area arc shown on hydrographs for well general1y were h.igher in May 1998 than in May 1990. Water-level fluctuations for the I"'anning, J.L., 1997, Water use in Georgia by county for 1995: Georgia Geologic Survey Information 1990-98, corresponding to decreased pt1mp:1ge from the Upper Floridan aquifer. Geologic Survey, and other State and local agencies, maintains a network of approxi­ southwestern, south-central, noTth-central, and coastal areas. These hydrologic areas are 13L003 in eastern Dougherty County and well 09F520 in central Decatur County. Water period 1990-98 are illustrated by the hydrographs for well25QOOI in southern Circular 101, 95 p. Pumpage decreased from about 70 Mgalfd in 1990 (Fanning, 1992), to 64 Mgal/d in mately 1,050 water-level monitoring well s, including 153 equipped with similar to those used by Clarke (1987), except for the coastal area which now includes levels in these wells generally are highest in the winter and early spring and decline from Montgomery County and well21T001 in western Laurens County. Typical seasonal Fanning, J.L., 1999, Water use in CoastaJ GeQrgia by county and source, 1997; and water use trends, 1997 (Fanning, 1999). Water l ev~t l s in the Jesup-DoctortoWh area are illustrated by 1980- 97: Georgia Geologic Survey Information Circular 104,37 p. continuous water-level recorders. Ware and Toombs Counties. The coastal area bas been further subdivided by major late summer to early winter because of decreased precipitation and increased seasonal water-level variations are indicated by high water levels during late winter-early spring and low water levels during the summer and fall. Although water levels in well21T001 the hydrograph for well 30L003. The sharp peaks on the hydrograph represent rapid Hicks, D.W., Gill, H. E. , and Longsworth, S.A., 1987, Hydrogeology, chemical quality, and availability This report illustrates and describes the potentiometric surface of the Upper Floridan pumping centers, into the Savannah, Jesup-Doctortown, Brunswick, and St Marys, Ga.­ irrigation pumping. The seasonal pattern of irrigation pumping is evident on the hydro­ water-level rises due to reductions in nearby industrial pumping. of ground water in.the Upper Floridan aquifer, Albany area, Georgia: U.S. Geological Survey Water­ Femandina Beach, Fla., areas. graph for well 09F520 in Decatur County-sharp water-level declines starting in the early show little trend, the water level in well25QOOI declined during 1990- 98, a continuation aquifer in Georgia and adjacent parts of Alabama, Florida, and South Carolina for May Resources Investigations Report 87-4145, 52 p. of a trend that bas been recorded since 1966. 1998, and water-level trends in Georgia for the period May 1990 to May 1998. The Recharge to the Upper Floridan aquifer predominately is derived from precipitation that spring and exltmding into early fall reflect irrigation pumping. Both hydrographs show Brunswick area Hicks , D.W., 1995 , The Independence bay flood of 1994 and effects on water levels in the Upper Floridan potentiometric surface, which represents the altitude at which water would have stood in infiltrates the aquifer in areas where the aquifer crops out or is near land surface and the pronounced water-level rises in 1994 and 1998 that correspond to periods of flooding aquifer, Albany area, Georgia: Proceedings of the 1995 Georgia Water Resources Conference, held April In the Brunswick area, a cone of depression has developed as a result of industrial and tightly cased wells open to the Upper Floridan aquifer, was constructed by using water­ confining unit is thin or missing. In the south-central area near Valdosta, the aquifer also along the Flint River. Heavy rainfall caused the Flint River to flood in July 1994, resulting Coastal area 11- 12, 199~ at the University or Georgia, K.J. Hatcher ed. Institute of Natural Reso urces, University of municipal pumping. The cone extends throughout most of eastern and southeastern level and pressure measurements collected from more than 2,000 wells during May l-26, receives recharge directly from the Withlacoochee River which flows into sinkholes that in record high water levels in the Upper Floridan aquifer (Hicks, 1995). ln March 1998, a The configuration of the potentiometric sutface of the Upper Floridan aquifer in the Georgia, Athens Ga. , p, 317·322. Glynn County, and the water level near the center of the cone was less than-10ft in 1998. The potentiometric-surface map is used to better understand ground-water flow in have been exposed by erosion of the overlying confining unit (Krause, 1979; McConnell flood occurred along the Flint River that resulted in even higher ground-water levels than coastal area is characterized by four large cones of depression resulting from pumping Kellam, M.P., and Gorday, L.L., 1990, Hydrogeology of the Gulf Trough-Apalachicola Embayment area, May 1998. Although pumping rates are similar, the depth of the cone of depression at Georgia: Georgia Otologic Survey Bulletin 94, 74 p. the Upper Floridan aquifer. In addition, the potentiometric-surface map and related and Hacke, 1993). those recorded during the 1994 flood. Water levels were higher in March 1998 than in July from the Upper Floridan aquifer. Major pumping centers at Savannah, Jesup-Doctortown, 1994 because the 1998 flood occurred when water levels were already at or near the Brunswick is smaller than at Savannah and Jesup-Doctortown, This shallower depth Krause, R.E. 1979 , Geohydrology of Brooks, Lowndes, and westem Echols Counties, Georgia : U.S. water-level data will be used in the development of ground-water-flow models of the One of the more prominent features of the potentiometric surface is the Gulf Trough, an Brunswick, and St Marys, Ga.-Fernandina Beach, Fla., have a pronounced effect on the annual seasonal high due to normal winter recharge. Conversely, during the July 1994 results from leakage from underlying units and the relatively greater thickness and Geological Survey Water-Resources Investigations Report 78-1 17, 48 p. aquifer system for the coastal area of Georgia. area where the hydraulic brradient abruptly steepens. The Gulf Trough consists of fine configuration of the potentiometric surface of the Upper Floridan aquifer. During 1997, permeability of the Upper Floridan aquifer at Brunswick (Krause and Randolph, Krause, R.E. , arid Hayes, L.R., 1981 , Potentiometric surface of the principal artesian aquifer in Georgia, May flood, the water level in the aquifer was nearing its annual seasonal low and the water-level about 347 Mgal/d of water was withdrawn from the Upper Floridan aquifer in the coastal This report follows a similar format used by Krause and Hayes (1981) and Clarke (1987). grained, dense, low permeability limestone overlain by a thick sequence of Miocene 1989). Water levels in the Brunswick area generally rose during May 1990 to May 1980: Georgia Geologic Survey Hydrologic Atlas 6, scale I: I ,000,000, 1 sheet. rise was less pronounced (David W. Hicks, U.S. Geological Survey, ural comm., 1998). and younger sediments, that extends from Colquitt County in the southwestern area to area (Fanning. 1999). Water le vels iQ. the coastal area generally were higher in May 1998 The 1998 potentiometric-surface map is more detailed than previous maps because of 1998, corresponding to decreased pumpage from the Upper Floridan aquifer. Pumpage Krause, R.E., and Randolph, R.B., 1989, Hydrogeology of the Floridan aquifer system in southeast Georgia than in May 1990 corresponding to a decrease in pumpage from about 369 Mgal/d in 1990 recent hydrogeologic studies of the Upper Floridan aquifer and covers a larger geographjc Bulloch County in the northern coastal area (Kellam and Gorday, 1990). This feature decreased from about 85 Mgal/d in 1990 (Fanning, 1992), to 65 Mgalld in 1997 and adjacent parts of Florida and South Carolina: U.S . Geological Survey Professional Paper 1403- D, 65 p. (Fanning, 1992), to 347 Mgal/d in 1997 (Fanning, 1999). area by including adjacent parts of Alabama, Florida, and South Carolina. Recent is indicated by tightly spaced potentiometric contours, particularly the 70- to 200-ft South-Central area (Fanning, 1999). The water-level rise during 1990- 9~ is illustrated by the hydrograph McConnell, J.b., and Hacke, C.M., 1993, Hydrogeology, water quality, and water resources development hydrologic studies have increased the number of wells in the water-level monitoring contours in the southwestern area and the 60- to 120-ft contours in the northern coastal Lowndes County, located in the south-central area, is a region having abundant for wel133H133. The sharp peaks on the graph represent rapid rises in water level potential of the Upper Floridan aquifer in the Valdosta area, south-central Georgia: U.S. Geological Survey Water-Resources Investigations Report 93-4044, 44 p. network, providing greater detail of the potentiometric surface. Three areas of the map area. Downgradient of the trough, the penneability of the Upper Floridan aquifer is high, sinkholes and sinkhole lakes that have formed where the aquifer crops out and the Savannah area due to reductions in nearby industrial pumping. show the greatest increase in detail-the north-central area and northern part of the as .indicated by the w idely spaced potentiometric-sUTt·ace contours. In areas up gradient of McConnell LB., .Busenberg, Eu rybiades, and Plummer, L.N., 1994, Water-resources data for the Valdosta overlying confining unit has been removed by erosion (Krause, 1979). TI1e With lacoochee Since development of the Upper Floridan aquifer in the Savannah area in the 1880's, coastal area (Clarke and West, 1997, 1998), the southwestern area near AJbany-Dougherty the trough the Upper Floridan aquifer is thin, near land surface, poorly confined, and the area, south-central Georgia, 1961-93: U.S. Geological Survey Open-File Report 94-350,58 p. River flows into these sinkholes and recharges the Upper Floridan aquifer at a rate of pumping from the aquifer has resulted in a water-level decline of more than 100ft and St Ma rys, Georgia -Fe rnandina Beach, Florida County (Hicks and others, 1987; McSwain, 1999), and the south-central area near pern1eability is lower. Here the potentiometric surface reflects surface topography and a McSwain, K.B., 1999, Hydrogeology of the Upper Floridan aquifer in the vicinity of the Marine Corps about 70 Mgal/d (Krause, 1979). This recharge produces a potentiometric high centered developme nt of a widespread cone of depression centered around Savannah. In 1998, the A cone of depression bas developed in the St Marys, Ga.-femadina Beach, Fla., area Valdosta-Lowndes County (McConnell and Hacke, 1993; McConnell and others, 1994). greater intercom1ection with streams, as indicated by contours that bend upstream, an Logistics Base m:ar Albany, Georgia: U.S. Geological Survey Water-Resources Investigations Repo rt around Brooks and Lowndes Counties. Water levels in the south-central area were water level near the center of the cone was 97 ft. The cone of depression in the Savannah as a result of industrial and municipal pumping. The cone of depression extends from 98-4202, 49 p. indication that water from the aquifer discharges to the streams. The ground-water data compiled for this report were obtained through the cooperation of generally higher in May l998than in May 1990. Water-level fluctuations in lhe south­ area encompasses larger area and is deeper than in other coastal areas, despite similar southeaslern Camden County, Ga., to northeastern Nassau County, FJa. Water levels in a Miller, J.A., 1986, Hydrogeologic framewo rk of the Floridan aquifer systt:m in Florida and parts of numerous private well owners, industries, and local municipalities who permitted access Water levels throughout the Coastal Plain generally were higher in May 1998 than in central area during 1990-98 are illustrated by the hydrographs for welll9E009, located rates of pumpage, because the permeability of the Upper Floridan aquifer in this area is the St Marys, Ga.-Femandina Beach, Fla., area had little trend during the period May Georgia, Alabama, and South Carolina: U.S. Geological Survey Professional Paper 1403-B, 91 p. to their wells for water-level measurements. Water-level measurements were made in May 1990. Water-k~ vel changes during lhis period are shown on selected hydrographs at Valdosta in Lowndes County; and 18K049, located at Tifton in Tift County. On both lower (Krause and Hayes, 1981). In addition to the Savannah area, a smaller cone of 1990 to May 1998, even though pumpage reportedly increased from about 38 Mgal!d Peck, M.F., t991, Potenliometric surface of the Upper Floridan aquifer in Georgia and adjacent parts uf cooperation with State and local agencies. In particular the authors would like to thank and the water-level-change map, and summarized by subarea in boxplots. These trends hydrographs, seasonal water-level fluctuations are indicated by high water levels during depression has developed southwest of Savannah in Liberty County because of industrial in 1990 (Fanning, 1992) to 40 Mgal/d in 1998 (Fanning, 1999). The water-level rise Alabama, Florida, and South Carolina, May-June 1990: U.S. Geological Survey Open-File Report Tom Pratt and Michael Maloney of the Northwest Florida Water Management District; are described in the following sections. late winter and early spring and low water levels during late summer and fall. pumpage of about 17.7 Mgalld (Fanning, 1999). Water levels in the Savannah area during 1990- 98 is illustrated by the hydro graph for well 33E027. 9 1-206,3 p.

/\ Potentiometric surface, May 1998 Water-level change, May 1990-98

Dai ly mean water level in weii18K049, Tift Cou nty Daily mean water level in weii 21T001. La ure ns Coun ty Water-level change, by subarea ~o ~~~~~~~~~~~~~~~~~~~~~~ ~o~~~~~~~T-~~~~~~~~~~~~~~ 50 r------~~------;

225 2<5 40 0 ( COLUMBIA I May 199EI EXPLANATION ul 2.20 ...J May 1990 240 May 1990 potooijometric 30 potentiometric May 199EI , . potentiometric 0 0 8 ~ 215 map potanl1ometric \ ~ m., 8 Outlier above 90th percentile ~ m•p ~ 20 00 w "' w 210 w 230 -i- 90th percentil e 75th percentile §< 1 205 §< 50ltl percentile 2~ 25th percenl"le ~ Bla~k w ~ ~ :t ~~~L . 1Oth percent1le w ~ 200 dala""'" are mossmg lL 220 rt;:A1i missing Olltlier below 10th -10 T p9rcentite 105 215 0 0 0 ----, -20 0 WATER-LEVEL CHANGE BETWEEN 1990 1991 1992 1993 1994 19

~0 L______~ e13L003 OBSERVATION WELL AN D Jesup-Doctortown St Marys IDENTIFICATION NUMBER

WELL DATA POINT • Dai ly mean water level in we11 36Q008. Chatham Cou nty ~' ~~~~~~~~~~~~~--~~--~~~~~ _,

May 1998 EXPLANATION _, polarotiometric m•p DOOLY May 1990 \((!. WELL DATA POINT-Symbol indicates ' ~ -ao potetltiomatric water-level difference, in feet, -05 =' May 1990-May 1996 lvvtrs;, ~ . .., Water-Level Rise Dai ly mean water level in weii 13LD03, Dougherty County •~ ..5 t Greater than 1 0 feet 215rm--~--~~~-ry--~~--~~~-P~~~~~~~~ May 1998 ~ t sto10feet potantiome"tric ~F"~I7ff/~t7.1~tJ ~ -100 March 1998 flood - map ii' 0 to 5 feet '" -105 irl 205 July 1994 flood May 1990 Water-Level Decline ~ poTentiometric -110 " 200 -1) 0 to 5 feet ~ m'p w -115 w 195 .. 5to10feet § _120 F. 'o';~'"""~~'":;;~~::O::uili~~~~"""~~~;::"""'"~~ .. Greater than < 190 -1990 1991 1992 1993 1994 1995 1996 1997 1998 ~ 10 feet ~ lEIS HENRY 100 Daily mean water level in weii30L003, Wayne County •o ~~~~~~~~~~~~~~~~~~~~~~~~"""

May 199EI L potentiometric May 1990 m•p potentiometric

Daily mean water level in well 09F520, Decatur County 1oorm~~~~~~~·~--~~~~~~~~~~~~~~

95 May 1990 March 1998 flood 10~~illu~~~~~~~~~~~~~~~~~~~ 1990 1991 1992 1900 1994 1995 1996 1997 1996 0: ~tentiometric July 1994 flood ~ 90 m"P ... • "< ...~­ _ ~ 85 missing w CLINCH ~ 00 Daily mean water level in weii 33 H1 33. Glynn County CHARLTON ~ 75 May 1996 " Effect of irrigation pumping potentiometric mop irl 15 May 11!98 ---., potentiometric " I ~ m•p I " 10 • ~ p w May 1990 5 poll!rlliornelric I /' I • ~ GEORGIA NASSAU • ~ 0 0z . )~ < data are "F'i_ OR!J5A:- •.---l, -1 mlss.ing""'" Base tram U.S. Geological Survey ~ -5 Daily mean water level in weii 19E009. Lowndes County digital data, t:100 ,000, 1977-81, I Albers Equal-Area Conic projeclion < -10 1o5 m~~~--~~~--~~~~~~~~~~~~~~ Standard pamllels 29"30 ". central meridian 83°30' ~ May 1998 • I ~ -15 100 potentiometric I m•p • 95 • I • BAKER May 1990 • potentiometric • CLINCH m"P Daily mean water level in weii 33E027, Camd en County 0 15 20 25 30 MILES 5 10 "~~~~~~~~~~~~~~~~~~~ 0 5 10 i 5 20 25 30 KILOMETERS May 199e 4C potentiometric I ~ ECHOLS < MayHI90 m"P ~ 35 potenliornatric I 0 10 20 30 MILES ____L_ w m"P ---- ~ ~ 0 10 20 30 KILOMETERS ~ 25 ~ mo$$o~ g wL-~~~~~~~~~~~~--~~~~~ 1990 1991 1992 1993 1994 1995 1996 19!il7 1998

Design by Caryl J. Wipperfunhl

POTENTIOMETRIC SURFACE OF THE UPPER FLORIDAN AQUIFER IN GEORGIA AND ADJACENT PARTS OF ALABAMA, FLORIDA, AND SOUTH CAROLINA, MAY 1998, AND WATER-LEVEL TRENDS IN GEORGIA, 1990-98 bv