Stream-Aquifer Relations and the Potentiometric 

Surface of the Upper Floridan Aquifer in the Lower 

Apalachicola–Chattahoochee–Flint River Basin in 

parts of Georgia, Florida, and Alabama, 1999–2000

Water-Resources Investigations Report 02-4244 

Prepared in cooperation with the 

Georgia Department of Natural Resources 

Environmental Protection Division 

Georgia Geologic Survey 

U.S. Department of the Interior 

U.S. Geological Survey 
Cover photograph: Radium Springs, Albany, Georgia, 1995 

Photograph by: Alan M. Cressler, U.S. Geological Survey 

“Originally called ‘Skywater’ by the Creek Indians who held sacred rites on its banks and 

later referred to as ‘Blue Springs’ by early Albany residents, ‘Radium Springs’ got its 

latest name when developer Baron Collier tested the water and found trace elements of 

radium, thought to be a healing substance at that time. The largest natural spring in 

Georgia, Radium is considered one of Georgia’s seven natural wonders.” 

(Albany [Georgia] Area Chamber of Commerce, accessed October 9, 2002, 

at URL http://www.albanyga.com/cvb/history1918.html) 
Stream-Aquifer Relations and the 

Potentiometric Surface of the Upper 

Floridan Aquifer in the Lower Apalachicola–

Chattahoochee–Flint River Basin in parts of 

Georgia, Florida, and Alabama, 1999–2000

By Melinda S. Mosner

______________________________________________________________________________

U.S. Geological Survey

Water-Resources Investigations Report 02-4244

Prepared in cooperation with the

Georgia Department of Natural Resources

Environmental Protection Division

Georgia Geologic Survey

Atlanta, Georgia

2002

U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

CHARLES G. GROAT, Director

Any use of trade, product, or firm names is for descriptive purposes

only and does not imply endorsement by the U.S. Government

For additional information, please write to:

State Representative

U.S. Geological Survey

3039 Amwiler Road, Suite 130

Atlanta, GA 30360-2824

http://ga.water.usgs.gov/

Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Denver Federal Center

Box 25286

Denver, CO 80225-0286
CONTENTS iii

CONTENTS

Page

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Purpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Description of study area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Physiography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Hydrogeologic setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Ground-water level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Previous investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Well- and stream-numbering systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Estimation of ground-water seepage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Precipitation trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Stream-aquifer relations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Conceptual model of stream-aquifer flow system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Ground-water contribution to streamflow (baseflow) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Linear regression analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Hydrograph separation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Analysis of baseflow estimation methods and discussion of error . . . . . . . . . . . . . . . . . . . . . 23

Potentiometric surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

References cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Appendix A—Wells measured in the lower Apalachicola–Chattahoochee–Flint River Basin, 

1999–2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Appendix B—Streamgaging stations measured in the lower Apalachicola–Chattahoochee–Flint River 

Basin, 1999–2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Appendix C—Springs measured in the lower Apalachicola–Chattahoochee-Flint River Basin, 

1999–2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
iv CONTENTS

Page

ILLUSTRATIONS

Plate 1. Location of wells, surface-water sites, and springs measured in the lower 

Apalachicola–Chattahoochee–Flint River Basin, October 1999–August 2000 . . . in pocket

Figures

Figure 1. Map showing location of study area, boundaries of the lower Apalachicola–

Chattahoochee–Flint River Basin, and physiographic districts of the Coastal 

Plain Province . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2. Geologic and hydrologic units in the lower Apalachicola–Chattahoochee–

Flint River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figures 3–6. Graphs showing:

3. Water-level fluctuations in well 10G313 in the Upper Floridan aquifer, 1980–2001. . . . . . . 6

4. Differences in baseflow separation among the fixed-interval, sliding-interval, 

and local-minimum methods of HYSEP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

5. Cumulative departure from normal precipitation for selected sites in the lower

Apalachicola–Chattahoochee–Flint River Basin, Bainbridge and Cordele, Georgia,

October 1949–September 1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figures 6–10. Maps showing:

6. Stream seepage along selected stream reaches in the lower Apalachicola–

Chattahoochee–Flint River Basin, October 1999 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

7. Stream seepage along selected stream reaches in the lower Apalachicola–

Chattahoochee–Flint River Basin, April 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

8. Stream seepage along selected stream reaches in the lower Apalachicola–

Chattahoochee–Flint River Basin, August 2000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

9. Stream seepage along Muckalee Creek near Leesburg, Georgia, 

(A) October 1999 and (B) August 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

10. Stream seepage along Spring Creek between Colquitt and Brinson, Georgia, 

(A) October 1999 and (B) August 2000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure11. Graph showing mean-monthy baseflow and runoff for Muckalee Creek, Georgia, 

1980–2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

12. Schematic diagram of the conceptual hydrologic flow system in the lower 

Apalachicola–Chattahoochee– Flint River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

13. Graph showing comparison of water level in well 12L028 to streamflow at 

gage 02353000 on the Flint River at Newton, Georgia, 1984–2000 . . . . . . . . . . . . . . . . . . . 18

14. Maps showing statewide distribution of percent of normal streamflow for 

(A) May 2000 and (B) August 2000; and (C) the ratio of 1999 mean-annual 

streamflow to long-term runoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
CONTENTS v

Page

Figures 15–18. Graphs showing:

15. Distribution of mean-daily streamflow for (A) Kinchafoonee Creek near Dawson, 

Georgia; (B) Flint River at Newton, Georgia; (C) Apalachicola River at 

Chattahoochee, Florida; and (D) Kinchafoonee Creek at Preston, Georgia . . . . . . . . . . . . . . 20

16. Duration of mean-daily streamflow for selected sites in the lower 

Apalachicola-Chattahoochee-Flint River Basin that have a direct 

hydraulic connection to the Upper Floridan aquifer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

17. Duration of mean-daily streamflow for selected sites that have a hydraulic 

connection to the Cretaceous aquifers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

18. Comparison of mean-annual baseflow and discharge at the 85- and 

90-percent duration points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figures 19–21. Maps showings:

19. Generalized potentiometric surface of the Upper Florida aquifer in the lower 

Apalachicola–Chattahoochee–Flint River Basin, October 1999. . . . . . . . . . . . . . . . . . . . . . . 26

20. Generalized potentiometric surface of the Upper Floridan aquifer in the lower 

Apalachicola–Chattahoochee–Flint River Basin, August 2000 . . . . . . . . . . . . . . . . . . . . . . . 27

21. Potentiometric surface of the Upper Floridan aquifer in the lower 

Apalachicola–Chattahoochee–Flint River Basin, May 1998 . . . . . . . . . . . . . . . . . . . . . . . . . 28

Tables

1. Climate data for Arlington, Calhoun County, Georgia, 1959–2001 . . . . . . . . . . . . . . . . . . . 6

2. Streamgaging stations used for hydrograph separation and flow-duration 

analyses in the lower Apalachicola–Chattahoochee–Flint River Basin . . . . . . . . . . . . . . . . 8

3. Mean-annual streamflow and unit-area discharge of selected streams in the lower 

Apalachicola–Chattahoochee–Flint River Basin for relatively wet conditions of 

1994 and drought conditions of 1999 and 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

 4. Mean-annual percentage of total streamflow that is baseflow, by month, in 

selected streams in the lower Apalachicola–Chattahoochee–Flint River Basin, 

1980–2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5. Flow-duration index for selected streams in the lower Apalachicola–

Chattahoochee–Flint River Basin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6. Coefficient of determination (r2) and residual standard error for flow durations 

evaluated as indicators of baseflow for selected sites in the lower Apalachicola–

Chattahoochee–Flint River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

7. Comparison of unit-area ground-water discharge estimates using field 

measurements of baseflow, hydrograph separation, and regression techniques 

for selected streams in the lower Apalachicola–Chattahoochee–Flint River 

Basin, October 1999 and April and August 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
vi CONTENTS

HORIZONTAL AND VERTICAL DATUMS

Horizontal coordinate information is referenced to the North American Datum 

of 1983 (NAD 83). Historical data collected and stored as North American 

Datum 1927 have been converted to NAD 83 for this publication.

Vertical coordinate information is referenced to the North American Vertical 

Datum of 1988 (NAVD 88). Historical data collected and stored as National 

Geodetic Vertical Datum of 1929 have been converted to NAVD 88 for this 

publication.
Stream-aquifer relations and the potentiometric surface of the ABSTRACT 1

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Stream-Aquifer Relations and the Potentiometric Surface 

of the Upper Floridan Aquifer in the Lower Apalachicola–

Chattahoochee–Flint River Basin in parts of Georgia, 

Florida, and Alabama, 1999–2000

By Melinda S. Mosner

ABSTRACT

The Upper Floridan aquifer is the principal source 

of water for domestic and agricultural use in the 

lower Apalachicola–Chattahoochee–Flint (ACF) 

River Basin. Recent drought and increased water 

use have made understanding surface- and groundwater relations a priority for water-resource 

managers in the region. From July 1999 through 

August 2000, less than normal precipitation 

reduced streamflow in the area to less than 12 

percent of average mean-daily streamflow and 

ground-water levels reached record or near-record 

lows. Effects of drought on stream-aquifer 

interactions in the basin were evaluated using 

baseflow estimation, ground-water seepage 

calculations, and potentiometric-surface maps. 

Ground-water discharge to streams, or baseflow, 

was estimated using three methods: field 

measurements, hydrograph separation, and linear 

regression analysis. Results were evaluated 

seasonally—October 1999, April 2000, and 

August 2000—and for the period of record at four 

surface-water stations located on Kinchafoonee, 

Spring, Muckalee, and Turkey Creeks. Estimates 

of baseflow also were compared annually; groundwater discharge during the drought years, 1999–

2000, was compared with ground-water discharge 

during a relatively wet year, 1994.

Hydrograph separation indicated decreased baseflow of streams as the water level in the Upper 

Floridan aquifer declined. Mean-annual baseflow 

for Kinchafoonee, Spring, Muckalee, and Turkey 

Creeks ranged from 36 to 71 percent of total 

streamflow during the period of record. In 1994 

baseflow accounted for only 37 to 56 percent of 

total streamflow, in 1999 baseflow comprised 

from 60 to 73 percent of total streamflow, and in 

2000 baseflow comprised from 56 to 76 percent of 

streamflow. The percentage of total streamflow 

attributed to ground water increased during the 

drought, whereas other components of streamflow 

decreased (overland flow, interflow, and channel 

precipitation). Even though relative ground-water 

contributions were increased, the volume of water 

discharged from the aquifer to streams decreased 

during the drought as the Upper Floridan aquifer 

water level declined. Unit-area mean-annual 

ground-water discharge ranged from 0.60 to 0.79 

cubic foot per second per square mile ([ft3

/s]/mi2) 

in 1994, from 0.24 to 0.58 (ft3/s)/mi2 in 1999, and 

from 0.13 to 0.33 (ft3

/s)/mi2 in 2000. Groundwater contributions to streamflow are high in 

winter, when evaporative demands are low, and 

low in summer, when evaporative demands are 

high. Linear regression analysis of stream-aquifer 

relations in the lower ACF River Basin shows 85- 

or 90-percent flow durations as reasonable 

estimates of baseflow.
2 INTRODUCTION Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

INTRODUCTION

Increased demand for and multiple uses of the limited 

ground- and surface-water resources in the lower 

Apalachicola–Chattahoochee–Flint (ACF) River 

Basin have become concerns for water managers at 

both the State and Federal levels. The lower ACF River 

Basin encompasses nearly 6,800 square miles (mi2) in 

southwestern Georgia, northwestern Florida, and 

southeastern Alabama (fig.1). Previous studies have 

shown a close hydraulic relation between the groundand surface-water systems of the basin (Torak and 

McDowell, 1995; Hicks and others, 1987). Groundwater withdrawals in the basin have lowered the water 

level in the Upper Floridan aquifer and resulted in 

reduced baseflow of streams. Downstream users—

those who rely on the resource for municipal, agricultural, and industrial uses—are most affected by 

reductions in streamflow. Although water use in the 

basin has been a concern for several years, recent 

drought conditions have exacerbated the already 

limited ground- and surface-water resources and 

shown the complexity of stream-aquifer relations in the 

area. The dry or nearly dry stream conditions that 

occurred during recent drought conditions have 

focused water managers’ attention on the multiple and 

competing uses of water resources in the basin, along 

with potential conflicts among users.

Because ground water is the major water source in the 

basin, and the potential exists for pumping-induced 

streamflow reduction to impact downstream users, a 

quantitative understanding of stream-aquifer relations 

is essential to effectively manage water resources in the 

lower ACF River Basin. In response to this need, the 

Georgia Department of Natural Resources, 

Environmental Protection Division, Georgia Geologic 

Survey requested that the U.S. Geological Survey 

(USGS) conduct an investigation to improve the 

understanding of stream-aquifer relations in the lower 

ACF River Basin and evaluate how ground-water 

pumping and drought conditions affect those relations.

Purpose and Scope

This report describes stream-aquifer relations in the 

lower ACF River Basin in southwestern Georgia and 

northwestern Florida by evaluating the effects of 

drought on the ground-water level of the Upper Floridan

aquifer and ground-water discharge to (or baseflow of) 

streams. This description is part of a larger study to 

investigate hydrogeologic heterogeneity and to improve 

the understanding of the effects of ground-water 

pumping and drought on the water resources of the 

lower ACF River Basin. This report includes:

• ground-water seepage maps that indicate areas 

where streams gained or lost water as a result 

of surface-water interaction with the Upper 

Floridan aquifer during October 1999 and 

August 2000;

• a comparison of methods for estimating 

ground-water discharge (ground-water 

seepage) to streams; and 

• potentiometric-surface maps of the Upper 

Floridan aquifer for October 1999 and 

August 2000, based on field measurements 

taken during those times.

Ground-water levels in wells and stream discharge 

measured in October 1999 and August 2000 were used 

to construct potentiometric-surface maps and stream 

seepage maps. Net gains or losses to streamflow 

(ground-water seepage) for the two time periods were 

determined along selected stream reaches to estimate 

the quantitative interaction between surface water and 

ground water. Changes in ground-water altitudes and 

flow directions were compared using potentiometricsurface maps. In addition, hydrograph-separation 

techniques and linear regression analysis were used to 

estimate ground-water contribution to streamflow at 

four streamgaging stations for normal and extreme 

climatic conditions. Maximum ground-water discharge 

to streams was estimated using streamflow during a 

relatively wet year, 1994. Minimum ground-water 

discharge was estimated using streamflow during the 

drought year of 1999.

Data utilized as part of this evaluation include: 

historical and current (1999–2000) water-level data 

from 324 wells, stream-discharge data from 74 

streamgaging stations, ground-water discharge data 

from 12 springs, current precipitation data from 2 

over-water weather stations on Lake Seminole, and 

precipitation data from the National Climatic Data 

Center for 2 National Weather Service weather stations 

located in the lower ACF River Basin.
Stream-aquifer relations and the potentiometric surface of the INTRODUCTION 3

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 1. Location of study area, boundaries of the lower 

Apalachicola–Chattahoochee–Flint River Basin, and physiographic 

districts of the Coastal Plain Province (modified from Torak and 

other, 1996).

30°

31°

32°

85° 84°

Map

area

0

0

10

10

20 MILES

20 KILOMETERS

SEMINOLE

MILLER COLQUITT

WORTH

TURNER

CRISP

DOUGHERTY CALHOUN

RANDOLPH

STEWART

CLAY

TERRELL

LEE

MITCHELL

BAKER

DOOLY

SUMTER WEBSTER

GADSDEN

GULF

JACKSON

CALHOUN

HOUSTON

HENRY

BARBOUR

DECATUR

LIBERTY

FRANKLIN

GRADY

EARLY

Blountstown

Dothan

Chattahoochee

Bristol

Woods

Orange

Bainbridge

Cordele

Albany

Apalachicola

Eufaula

UPDIP

LIMIT

OF UPPER

FLORIDAN

AQUIFER

PELHAM

ESCARPMENT

AL

FL

FL

GA

FALL

LINE

HILLS

GULF COASTAL LOWLANDS

DOUGHERTY

PLAIN

TIFTON

UPLANDS

Base modified from U.S. Geological Survey

1:100,000-scale digital data

AL GA

Gulf of Mexico

Lake

Seminole

ALABAMA

Apalachicola–

Chattahoochee–

Flint River Basin

GEORGIA

FLORIDA

EXPLANATION

LOWER APALACHICOLA–

 CHATTAHOOCHEE–FLINT 

RIVER BASIN

PHYSIOGRAPHIC DISTRICT 

BOUNDARY

Flint River

Chattahoochee R Apalachicola River

Walter F.

George

Reservoir
4 INTRODUCTION Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Description of Study Area

The 6,800-mi2 study area includes Lake Seminole and 

the land area that contributes ground- and surfacewater flow into and out of the lake (fig.1). In Georgia, 

the study area includes all or parts of Baker, Calhoun, 

Crisp, Decatur, Dougherty, Early, Lee, Miller, Mitchell,

Randolph, Seminole, Sumter, Terrell, and Worth 

Counties. In Florida, the study area includes all or 

parts of Gadsden and Jackson Counties. In Alabama, 

the study area includes part of Houston County.

Physiography

The lower ACF River Basin lies within the Coastal 

Plain physiographic province in southwestern 

Georgia, northwestern Florida, and southeastern 

Alabama and is drained by the Apalachicola, 

Chattahoochee, and Flint Rivers and their tributaries 

(Torak and others, 1996) (fig. 1). The northern extent 

of the study area is in the Fall Line Hills district near 

the updip limit of the Ocala Limestone (Clark and 

Zisa, 1976). The Fall Line Hills district is highly 

dissected, with steep slopes, and streams that are 

from about 50 to 250 feet (ft) below adjacent ridges. 

Relief diminishes gradually where the Fall Line Hills 

district grades into the Dougherty Plain (Torak and 

others, 1996). 

The Dougherty Plain is a nearly level lowland that 

ends where the Fall Line Hills district and Tifton 

Uplands meet (Clark and Zisa, 1976). Formed by 

erosion, land-surface altitude ranges from about 300 ft 

at the northern extent of the plain to about 77 ft at Lake 

Seminole. Relief in the Dougherty Plain rarely 

exceeds 20 ft, and slopes average about 5 ft per mile 

(Hicks and others, 1987). Karst topography and 

solution and erosional features define the landscape of 

the Dougherty Plain. Continual formation of 

sinkholes, the bottoms of which are filled with lowpermeability sediment and hold water year round, is 

responsible for the development of the numerous 

ponds and wetlands characteristic of the region. 

Underground channels formed from active dissolution 

of the Ocala Limestone commonly capture surface 

water; these underground channels account for a 

significant percentage of drainage in the Dougherty 

Plain (Hicks and others, 1987).

To the east, a well-defined northwest-facing feature 

called the “Pelham Escarpment,” which forms a 

prominent regional boundary between the Tifton 

Upland and the Dougherty Plain, borders the basin 

(Hicks and others, 1987). The crest of the Pelham 

Escarpment forms a topographic and surface-water 

divide between the Flint River to the west and the 

Ochlockonee and Withlacoochee Rivers to the east 

(Torak and others, 1996). In northwestern Florida, the 

Tifton Uplands are termed the Tallahassee Hills, in 

which the southern limit of the study area is located. 

Land-surface altitude in that area ranges from about 

330 ft near the Georgia-Florida State line to about 100 

ft south of the study area. 

Hydrogeologic Setting

Pre-Cretaceous to Quaternary sediments underlie the 

Coastal Plain physiographic province. In the study 

area, these sediments consist of alternating sand, clay, 

dolomite, and limestone, which dip gently and thicken 

to the southeast (Hicks and others, 1987). The 

Dougherty Plain is characterized by a highly transmissive ground-water flow system, developed through 

solutioning and karst processes in the Ocala Limestone, which is the main water-bearing unit of the 

Upper Floridan aquifer. This flow system is characterized by high rates of direct recharge through sinkholes, indirect recharge by vertical leakage through the 

overburden, and discharge to surface-water bodies 

such as the Flint and Chattahoochee Rivers (Torak and 

others, 1996). The ability of geologic units to function 

as an aquifer, transmit usable amounts of ground 

water, or provide leakage of water between aquifers 

and surface water is determined, in part, by the varying 

hydrologic characteristics of thickness and hydraulic 

conductivity. 

The vertical and areal distribution of the Upper 

Floridan aquifer adds complexity to the dynamics of 

stream-aquifer interactions. The Upper Floridan 

aquifer ranges in thickness from a few feet at its updip 

limit to greater than 700 ft in Florida, and generally is 

exposed along major river reaches where erosion has 

removed the overburden. Dissolution of limestone by 

fluctuating ground-water levels and infiltrating rainfall 

have produced secondary permeability in the Ocala 

Limestone, making the aquifer extremely productive. 

Solution conduits between the Pelham Escarpment 

and the Flint River transmit large amounts of ground 

water from the Upper Floridan aquifer to springs that 

discharge along streams. The relative rate at which 

ground water moves through the aquifer is determined 
Stream-aquifer relations and the potentiometric surface of the INTRODUCTION 5

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

by the hydraulic gradient and the amount of solutioning and connectivity of conduits, which result in 

aquifer transmissivity of 2,000–300,000 feet squared 

per day (ft2/d); transmissivity is lower at the updip 

limit of the Ocala Limestone, where the aquifer is 

relatively thin, and increases southward as the aquifer 

thickens (Hicks and others, 1987). 

Throughout much of the study area, the Upper 

Floridan aquifer is unconfined or semiconfined, and 

ground-water discharge mainly is by springflow and 

seepage to surface-water bodies (Johnston and Bush, 

1988). Because of the connectivity between the Upper 

Floridan aquifer and surface-water features, only the 

Ocala Limestone and younger units were considered 

important to stream-aquifer relations in the study area. 

Included are sediments of late Eocene age and 

younger—which, in ascending order, are the Lisbon 

Formation, Clinchfield Sand, Ocala Limestone, 

Suwannee Limestone, Tampa Limestone, Hawthorn 

Group, Miccosukee Formation, and terrace and 

undifferentiated deposits (fig. 2). Details about these 

geologic units are contained in Hayes and others 

(1983), Miller (1986), Hicks and others (1987), Bush 

and Johnston (1988), Torak and others (1996), and 

Torak and McDowell (1995).

Ground-Water Level

The ground-water level in the Upper Floridan aquifer 

fluctuates seasonally in response to recharge from 

precipitation, discharge from pumping, evapotranspiration, interaction with surface-water features, and 

periods of reduced precipitation and drought. Water 

level is highest during winter and spring and lowest 

during summer and fall. Generally, recharge begins in 

early winter, and the water level rises quickly in 

response to precipitation. During late spring and early 

summer, the water level declines in response to 

increased agricultural water use (pumping) and 

evapotranspiration. These factors also contribute to 

decreased water-level response to precipitation by 

reducing infiltration. Seasonal ground-water-level 

fluctuations range from 2 ft to nearly 30 ft (fig. 3). 

The ground-water level in the overlying semiconfining 

units is similarly affected by seasonal fluctuations and 

also may be affected by changes in river stage. 

Although withdrawals from the Upper Floridan 

aquifer have averaged about 66 million gallons per day 

(Mgal/d) for more than 30 years, the aquifer has 

remained in equilibrium; recharge to the aquifer from 

normal annual precipitation is equal to discharge from 

both natural and human-induced conditions (Hicks

and others, 1987). In areas where the overlying semiconfining unit of the aquifer is thin or absent, the water 

level in the aquifer responds considerably to climatic 

conditions, declining rapidly during drought and 

recovering quickly during wet conditions. During the 

drought years of 1980–1981, water levels in wells in 

the Dougherty Plain declined to record or near-record 

lows; but with the return of normal precipitation, water 

levels recovered to pre-drought conditions (Hicks and 

others, 1987). Ground-water levels again declined to 

record or near-record lows during 1999–2000 in 

response to drought and pumping (fig. 3).

Figure 2. Geologic and hydrologic units in the 

lower Apalachicola–Chattahoochee–Flint River 

Basin (from Torak and others, 1996).

SERIES

GEORGIA

GEOLOGIC UNIT HYDROLOGIC

UNIT

 HOLOCENE

AND 

PLEISTOCENE

Terrace and 

undifferentiated 

deposits

MIOCENE

Miccosukee

Formation

Hawthorn

Group

Tampa

Limestone

Suwannee

Limestone

Undifferentiated overburden

(residuum)

Semiconfining

unit

EOCENE

Ocala Limestone

Clinchfield

Sand

Lisbon Formation

Upper

Floridan

aquifer

Lower

confining

unit
6 INTRODUCTION Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

WATER LEVEL, IN FEET

BELOW LAND SURFACE

19801982198419861988199019921994199619982000

50

40

30

60

70

Blank where

data missing

Figure 3. Water-level fluctuations in well 

10G313 in the Upper Floridan aquifer, 

1980–2001 (see plate 1 for location of well).

Climate

The climate of the study area is humid subtropical. 

The mean-annual temperature for a 43-year period 

(1959–2001) at Arlington, Georgia, is about 66.7 

degrees Fahrenheit (oF) (table 1; see plate 1 for 

location). The coldest months, December and January, 

average about 51.3oF; occasional freezing temperatures occur during this time. During the warmest 

months of July and August, the average temperature is 

about 81.1oF; however, temperatures near 100oF and 

above are not uncommon. Average annual rainfall at 

Arlington, is about 53.9 inches; highest monthly 

rainfall occurs in March; lowest monthly rainfall 

occurs in October (Georgia Automated Environmental 

Monitoring Network, 2002).

Previous Investigations

Several hydrogeologic investigations have been 

conducted in the study area. Sever (1965) described 

the hydrogeology in Decatur, Grady, and Seminole 

Counties, Georgia, and the water resources of the area 

surrounding Lake Seminole. Hayes and others (1983) 

described the hydrology of the Upper Floridan aquifer 

in the Dougherty Plain. Miller (1986) delineated the 

hydrogeologic framework of the Floridan aquifer 

system in parts of Alabama, Florida, Georgia, and 

South Carolina. Hicks and others (1987) investigated 

the hydrogeology, water quality, and availability of 

water in the Upper Floridan aquifer near Albany, 

Georgia. Johnston and Bush (1988) summarized the 

hydrology of the Floridan aquifer system. Bush and 

Johnston (1988) evaluated the ground-water 

hydraulics, regional flow, and ground-water 

development potential of the Floridan aquifer system 

in parts of Florida, Georgia, Alabama, and South 

Carolina. Torak and others (1993) evaluated the 

geohydrology and water-resource potential of the 

Upper Floridan aquifer in the Albany area, Dougherty 

County, southwest Georgia. Torak and McDowell 

(1995) and Torak and others (1996) evaluated the 

hydrogeology and ground-water resources in the lower 

ACF River Basin. Stewart and others (1999) also 

completed an investigation of water quality and 

hydrogeology of the Upper Floridan aquifer near 

Albany, Georgia. Results of selected investigations in 

the study area in Florida include reports by Vernon and 

others (1958) describing the geology of the area near 

Lake Seminole and Pratt and others (1996) describing 

the hydrogeology of the Northwest Florida Water 

Management District, which includes the study area in 

Florida. Albertson (2001), Mosner (2001), and Torak 

(2001) discussed the hydrogeology, water chemistry, 

and stream-aquifer relations, respectively, in the lower 

ACF River Basin, near Lake Seminole in southwestern 

Georgia and northwestern Florida.

a. Mean-annual temperature, 66.7°F.

Table 1. Climate data for Arlington, Calhoun County, 

Georgia, 1959–2001

[°F, degrees Fahrenheit; data from Georgia Automated 

Environmental Monitoring Network (2002)]

Month

Temperature (°F)a Average

precipitation

(inches)

Average

maximum

Average

minimum

January 61.9 38.1 5.37

February 65.5 40.8 4.92

March 72.5 46.9 6.09

April 80.4 53.8 3.79

May 86.2 60.6 3.65

June 90.7 67.6 5.10

July 92.3 70.3 4.96

August 91.8 69.8 4.80

September 88.5 65.8 3.84

October 80.6 54.7 2.65

November 72.1 46.0 3.15

December 64.9 40.1 5.61

MEAN 78.9 54.5 TOTAL 53.9
Stream-aquifer relations and the potentiometric surface of the Methods 7

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Well- and Stream-Numbering Systems

In this report, wells are identified in two ways, a numbering system based on USGS topographic maps and a 

numbering system developed by the Northwest Florida 

Water Management District. In Georgia, each 

7 1/2-minute topographic quadrangle map has been 

given a number and letter designation beginning at the 

southwestern corner of the State. Numbers increase 

eastward through 39 and letters increase alphabetically 

northward through “Z” and then become double-letter 

designations “AA” through “PP.” The letters “I,” “O,” 

“II,” and “OO” are not used. Wells inventoried in each 

quadrangle are numbered sequentially beginning with 

“1.” Thus, the third well inventoried in the Chattahoochee quadrangle (map 06D) is designated 06D003. 

Springs are considered ground-water sites and are 

identified in the same manner as wells. In Florida, the 

Northwest Florida Water Management District inventories wells using a numbered identification system; 

each well is assigned a four-digit identifier, for 

example 1640. Surface-water stations are identified by 

a numbering system used for all USGS reports and 

publications since October 1, 1950. The order of 

listing stations is in a downstream direction along the 

main channel. All stations on a tributary entering 

upstream from each mainstream are listed prior to that 

station. Each surface-water station is assigned a unique 

8- to 14-digit number. Each station number, such as 

02351890, begins with the 2-digit identifier “02,” 

which designates it as being a surface-water 

station, followed by the downstream-order number, 

“351890,” which can range from 6 to 12 digits.

Acknowledgments

The author extends appreciation to the many agencies 

that contributed to the collection of data used in this 

report, including the Northwest Florida Water 

Management District and the U.S. Army Corps of 

Engineers. Gratitude is extended to all landowners and 

land managers who allowed access to wells and springs 

to collect water-resource data. 

METHODS

Stream-aquifer relations were evaluated using existing 

hydrogeologic data, measurements of ground-water 

levels, stream and spring discharge, and climatological 

data. Field measurements of ground-water levels in 

wells and stream and spring discharge were collected 

during October 1999 and April and August 2000. Data 

were collected from 324 wells (Appendix A), 74 

streamgaging stations (Appendix B), and 12 springs 

(Appendix C) (plate 1). Ground-water levels were 

measured using a steel tape or an airline in wells so 

equipped. Streamflow was measured using conventional methods such as stream discharge and stage 

measurements, and acoustic Doppler current profiling. 

Land-surface altitude at wells was obtained using two 

methods, surveying and interpolation by plotting 

locations from global-positioning-system coordinates 

on 7 1/2-minute USGS topographic maps. Wells and 

streamgaging stations located on topographic maps are 

estimated to be accurate to within 40 ft; land-surface 

altitudes are estimated to be accurate to within 5 ft. 

Precipitation data were collected at two over-water 

weather stations on Lake Seminole and were obtained 

from the National Climatic Data Center for two 

National Weather Service weather stations located in 

Cordele and Bainbridge, Georgia (plate 1). Water-level 

data collected from wells and stream-stage measurements at streamgaging stations were used to construct 

water-level-altitude maps of the Upper Floridan aquifer 

in the lower ACF River Basin for October 

1999 and August 2000. Ground-water seepage maps 

were constructed by calculating the difference in 

streamflow between streamgaging stations. These 

maps were used to identify reaches where ground 

water discharges to streams, or where streams 

recharge the aquifer. Net stream gains or losses were 

calculated between streamgaging stations, and losing 

and gaining stream reaches were identified using 

these calculations. 

Estimation of Ground-Water Seepage

During periods of little or no rainfall, it is assumed that 

baseflow is composed entirely of ground-water 

discharge to the stream (ground-water seepage). 

Therefore, during the study period—October 1999–

August 2000—techniques used to estimate baseflow 

also result in reasonable estimates of ground-water 

seepage. Three methods of estimating ground-water 

seepage are compared in this report: field measurements, hydrograph separation, and linear regression 

analysis. Ground-water level and surface-water 

discharges measured in October 1999, April 2000, and 

August 2000 were used to calculate ground-water 
8 Methods Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

seepage along stream reaches. These results were 

compared with quantitative estimates of ground-water 

seepage from long-term data. 

Hydrograph separation was performed to evaluate the 

seasonality of ground-water seepage. The USGS 

computer program HYSEP (Sloto and Crouse, 1996), 

which modifies the methodology described by 

Pettyjohn and Henning (1979), was used for 

hydrograph separation. HYSEP uses one of three 

methods—fixed-interval, sliding-interval, or localminimum—to perform a separation. Each method 

employs an algorithm that systematically separates 

baseflow (ground-water seepage) from runoff by 

connecting low points on the streamflow hydrograph 

(Sloto and Crouse, 1996). The duration of surfacewater runoff is equivalent to the relation:

N=A0.2,

where N is the number of days for cessation of runoff, 

and A is drainage area of the basin. All three methods 

are an algorithm based on the interval 2N*, which is 

the odd integer between 3 and 11 that is nearest to 2N 

(Pettyjohn and Henning, 1979). 

• For the fixed-interval method, the lowest 

discharge in the 2N* interval is assigned to 

each day in that interval.

• For the sliding-interval method, the lowest 

discharge in the days prior to and after the 

interval 2N* is assigned, using the relation, 

0.5(2N*-1); intervals may overlap using this 

method.

• For the local-minimum method, the lowest 

discharge in the days prior to and after the 

interval 2N* also is assigned using the relation 

0.5(2N*-1); however, the intervals do not 

overlap.

Four sites—Kinchafoonee Creek, Muckalee Creek, 

Spring Creek, and Turkey Creek (table 2)—were 

selected to compare results for each method of 

determining ground-water seepage or baseflow 

separation. Field measurements at each site were 

divided by the basin area, yielding estimates of unitarea ground-water discharge, expressed as cubic foot 

per second per square mile ([ft3/s]/mi2

). Estimates 

calculated from hydrograph separation and linear 

regression analysis also were converted to unit-area 

discharge and compared with field measurements.

Table 2. Streamgaging stations used for hydrograph 

separation and flow-duration analyses in the lower 

Apalachicola–Chattahoochee–Flint River Basin

Station

number Station name

Drainage 

area 

(square 

miles)

Period of 

record

analyzed

02349900 Turkey Creek at Byromville, Ga. 45 1959–2000

02350600 Kinchafoonee Creek at 

Preston, Ga.

197 1905–1913,

1931–2000

02351890 Muckalee Creek at Ga. 195, near 

Leesburg, Ga.

362 1981–2000

02357000 Spring Creek near Iron City, Ga. 485 1938–2000

A plot showing all three methods of hydrograph separation for the gage at Turkey Creek near Byromville, 

Georgia, indicates the fixed-interval and slidinginterval methods are biased toward baseflow; thus, 

overpredict ground-water contribution to streamflow, 

or baseflow (fig. 4). For this reason, the localminimum method was used to estimate baseflow, or 

ground-water seepage. This method determines that if 

the discharge on a particular day is the lowest discharge in 0.5(2N*-1) days before and after that day, 

then that discharge is the local minimum. A straight 

line connects local minima, and baseflow between 

local minima is linearly interpolated. 

Stream reaches that are free of impoundments that 

regulate surface runoff, lack direct spring discharge, 

and are characterized by normal streamflow distributions are most acceptable for hydrograph-separation 

techniques. Since extreme climatic conditions during 

the short term also may bias baseflow estimation, 

mean-annual average estimates are more reliable than 

monthly or daily average estimates. 

Linear regression analysis was used to determine the 

flow duration that best estimates baseflow of streams 

in the study area. Linear regression analysis, however, 

is limited to specific hydrogeologic settings, as the 

setting influences the amount of infiltration and subsequent discharge to streams (White and Sloto, 1990). 

For instance, baseflow of streams in the glacial till/

outwash of Long Island can be estimated from the 

50-percent flow duration; whereas in the Cretaceous 
Stream-aquifer relations and the potentiometric surface of the Stream-aquifer relations 9

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

aquifers of southwest Georgia, baseflow is estimated to 

be in the 60–65-percent flow-duration range. Meanannual baseflow for 16 sites in the lower ACF River 

Basin was compared to flow durations ranging from Q1

to Q99 (that is, streamflows that are equaled or 

exceeded from 1 percent to 99 percent of the time, 

respectively) to derive a flow duration that is representative of baseflow. This flow duration then can be 

applied to all streams in the basin to estimate baseflow 

for any time interval, even daily.

10

100

1,000

10,000

DISCHARGE, IN CUBIC FEET PER SECOND

10

100

1,000

10,000

10

100

1,000

10,000

ONDJ FMAMJ J A S

1999 2000

Measured flow

Estimated baseflow Fixed interval

Sliding interval

Local minimum

Figure 4. Differences in baseflow separation 

among the fixed-interval, sliding-interval, and 

local-minimum methods of HYSEP (from 

Sloto and Crouse, 1996).

Precipitation Trends

Precipitation data for Cordele and Bainbridge, Georgia, 

were evaluated to estimate how variations in long-term 

precipitation affects ground-water recharge, fluctuations in streamflow, and ground-water levels throughout the basin. The cumulative departure from normal 

monthly precipitation for 1949–1999 was computed 

by adding successive monthly departures and plotting 

the result to illustrate seasonality and long-term effects 

of wet and/or dry conditions (fig. 5). Cordele is located

in the extreme northern part of the basin; and Bainbridge is in the southern part of the basin, near Lake 

Seminole (plate 1). Daily precipitation data for both 

sites were obtained from the National Climatic Data 

Center for the period October 1949–September 1999. 

The monthly departure from normal rainfall for the 

period 1949–1999 was used to evaluate precipitation 

trends (fig. 5). Above-average precipitation is represented graphically by a positive slope, and belowaverage precipitation by a negative slope (Atkins and 

others, 1996). During 1949–1999, precipitation at 

Cordele and Bainbridge was highly variable. Although 

both sites had a cumulative deficit for most of the 

period, a relatively wet period in the early 1990s 

resulted in a surplus of rainfall by 1998. For example, 

Bainbridge was 23 inches above normal rainfall and 

Cordele was 8 inches above normal by the end of 1998.

The onset of drought in the late 1990s, however, 

reduced this surplus; and by September 1999, the 

surplus was eliminated. Although the drought, which 

began in 1998, is not yet as severe as previous droughts 

(fig. 5), the spatial extent of the drought throughout the 

state has led to substantially reduced streamflow in the 

Dougherty Plain. 

STREAM-AQUIFER RELATIONS

During normal conditions, recharge of the Upper 

Floridan aquifer by rainfall and ground-water 

discharge to stream channels is in equilibrium (Hicks 

and others, 1987; Stewart and others, 1999). However, 

drought conditions during 1999–2000 reduced 

overland runoff, and stream discharge was derived 

largely from baseflow (table 3). In addition, the water 

level in the Upper Floridan aquifer declined in 

response to decreased recharge and increased 

pumping. In the northeastern part of the study area, 

some streams had losing reaches when the water level 
10 Stream-aquifer relations Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

in the aquifer declined beneath the stream stage and 

became dry as the water level in the aquifer declined 

beneath the stream channel. The aquifer is thin in the 

northeast, and transmissivity is less than 10,000 ft2

/d, 

retarding vertical ground-water flow between the 

aquifer and the stream channel (Johnston and Bush, 

1988). Conversely, the aquifer is thick and unconfined 

to the south and east, and the resulting transmissivity 

ranges from 10,000 to 1,000,000 ft2/d (Johnston and 

Bush, 1988). Under these conditions during the study 

period, streams were gaining, and ground-water 

discharge was the major component of baseflow. In the 

southern part of the study area, the potentiometric 

surface of the aquifer was higher than the altitude of 

the stream channel and the aquifer continued to 

discharge water into streams.

Ground-water discharge to streams in the lower ACF 

River Basin was highly variable during the study 

period. Ground-water seepage maps illustrate relative 

gains and losses along stream reaches in response to 

changes in runoff and ground-water discharge during 

drought conditions (figs. 6–8). On these maps, losing 

stream reaches are identified by hachures. Stream 

sections with a small basin area lost water to the 

aquifer more often than larger stream sections. In 

October 1999, several stream reaches with small 

drainage areas recharged the aquifer; however, a large 

section of the Flint River, from south of Montezuma 

to Warwick, Georgia, also lost water to the aquifer 

(fig. 6). In April and August 2000 only sections of 

streams in smaller basins recharged the aquifer (figs. 7 

and 8, respectively).

Figure 5. Cumulative departure from normal precipitation for selected sites in the lower

Apalachicola–Chattahoochee–Flint River Basin, Bainbridge and Cordele, Georgia,

October 1949–September 1999. CUMULATIVE DEPARTURE FROM NORMAL, IN INCHES

Bainbridge, Georgia

–100

–80

–60

–40

–20

0

20

40

Cordele, Georgia

–100

–80

–60

–40

–20

0

20

40

1949 1954 1959 1964 1969 1974 1979 1984 1989 1994 1999
Stream-aquifer relations and the potentiometric surface of the Stream-aquifer relations 11

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Table 3. Mean-annual streamflow and unit-area discharge of selected streams in the lower Apalachicola–

Chattahoochee–Flint River Basin for relatively wet conditions of 1994 and drought conditions of 1999 and 2000

[ft3/s - cubic foot per second; (ft3/s)/mi2 - cubic foot per second per square mile]

Station name 

and number

Meanannual 

streamflow

(ft3/s)

Meanannual 

percent 

baseflow

1994 1999 2000

Discharge 

(ft3/s)

Percent 

as

baseflow

Estimated 

unit-area

discharge 

([ft3/s]/mi2)

Discharge 

(ft3/s)

Percent 

as 

baseflow

Estimated 

unit-area

discharge 

([ft3/s]/mi2)

 Discharge 

(ft3/s)

Percent 

as 

baseflow 

Estimated 

unit-area

discharge 

([ft3/s]/mi2)

Turkey Creek at 

Byromville, Ga.

02349900

23 54 27 37 0.60 11 60 0.24 9 56 0.20

Kinchafoonee Creek 

at Preston, Ga.

02350600

136 67 144 56 .73 114 70 .58 64 66 .33

Muckalee Creek at 

Ga. 195, near 

Leesburg, Ga. 

02351890

247 63 287 44 .79 213 73 .58 116 66 .32

Spring Creek near 

Iron City, Ga.

02357000

313 65 329 48 .68 257 67 .53 62 76 .13

A detailed description of streamflows for sections of 

Muckalee Creek and Spring Creek during October 

1999 and August 2000 shows the variability and 

effects of drought on streamflows. Muckalee Creek, 

located in the northeastern part of the study area, lost 

water to the aquifer during October 1999 and August 

2000 (fig. 9). In October 1999, the reach between the 

gage near State Highway 195 and the gage near Leesburg, Georgia, lost 2 cubic feet per second (ft3/s) of 

flow; but farther downstream, between the gage near 

Leesburg and the gage downstream of Leesburg, the 

reach lost 23 ft3/s (fig. 9A). In August 2000, the gage 

located between State Highway 195 and the Leesburg 

gage lost 9 ft3/s to the aquifer (fig. 9B). Spring Creek, 

between Colquitt and Iron City, Georgia, was a losing 

reach in October 1999, drying to no flow at the Iron 

City gage; but farther downstream at Brinson, Georgia,

the reach gained 88 ft3

/s from the aquifer (fig. 10A), 

presumably from springs discharging along the 

channel and from diffuse ground-water leakage into 

the channel. As the drought became more severe in 

August 2000, the same trend was apparent as that 

observed in October 1999, with Spring Creek losing 

water between Colquitt and Iron City and gaining 

between Iron City and Brinson. However, the 

magnitude of gain or loss was greatly reduced in 

August 2000 because of drought effects, when 

compared to the trends exhibited in October 1999. 

By August 2000, declining water level in the aquifer 

resulted in 0.22 ft3/s lost to the aquifer between 

Colquitt and Brinson (fig. 10B).

Monthly baseflow estimates computed using HYSEP 

(Sloto and Crouse, 1996) illustrate the effects of 

drought on the relative contributions of runoff and 

baseflow to total streamflow (table 4). Estimates of 

baseflow generally are greater than runoff for the 

selected sites in the lower ACF River Basin, as 

indicated by baseflow comprising more than 50 

percent of total streamflow (table 4). Occasionally, the 

flashy nature of streams in the study area combined 

with the high intensity of rainfall during summer 

storms will cause runoff to exceed baseflow (table 4; 

fig. 11). 

Drought conditions increase the percentage of 

baseflow that contributes to total streamflow because 

surface-water runoff is reduced or absent. As a result, 

streams require ground-water discharge to maintain 

flow conditions. As ground-water levels declined to 

near-record or record lows throughout the lower ACF 

River Basin during August 2000, the hydraulic 

gradient to streams decreased, and for some reaches 

was reversed. This, in turn, reduced discharge to 

streams and, in some cases, resulted in losing or dry 

stream reaches. 
12 Stream-aquifer relations Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 6. Stream seepage along selected stream reaches in the 

lower Apalachicola–Chattahoochee–Flint River Basin, October 1999.

MITCHELL

BAKER

DECATUR GRADY

SEMINOLE

MILLER

EARLY

CALHOUN

RANDOLPH TERRELL

WORTH

SUMTER

LEE

TURNER

DOOLY

MACON

DOUGHERTY

CRISP

WEBSTER

STEWART

CLAY

SCHLEY

MARION

COLQUITT

TAYLOR

HOUSTON CHATTAHOOCHEE

0

0

0

0

0

18.4

0.3

211

122

13

47.8

25.5

1,060

138

210

149

126

880

23.2 85.3

16.9

38.9

12.4

1,220

16.9

148

151

1,370

1,600

1.93

307

2,270

17.2

2.97

1.17

3.62

7.64

25.6 10.6

2,750 0

0

0

0

0

0

0

0 0

0

88.4

0

10.1

1.43

851 10.9

4.69

9.62

10.8

4.14

0.25

5.55

40.1

19.9

0 10 20 MILES

0 10 20 KILOMETERS

Ellaville

Buena

Vista

Fort 

Gaines

Moultrie

Butler

Cusseta

Perry

Bainbridge

Colquitt

Iron

City

Blakely

Newton

Elmodel

Pelham

Camilla

Edison

Arlington

Albany

Leesburg

Warwick

Cordele

Byromville

Donalsonville

Morgan

Cairo

Sylvester

Ashburn

Dawson

Cuthbert

Americus Vienna

Montezuma

Preston

Lumpkin

Milford

Oakfield

Big

Slough

Chickasawhatchee Cr

Kiokee Cr

Cooleewahee Cr

Raccoon Cr

Long Br

Flint River

Flint

River

Muckalee Cr

Mill Cr

Turkey Cr Lilly Br Pennahatchee Cr

Sweetwater Cr

Hogcrawl Cr

Gum Cr

Cedar Cr

Muckaloochee Cr

Pachitla Cr

Carter Cr

Piney Woods Cr

Abrams Cr

Swift Cr

Dry Cr

Big Cypress Cr

Aycocks Cr

Sawhatchee Cr

Ichawaynochaway Cr

Fishpond

Spring Cr

Drain Lake

Seminole

Kinchafoonee Cr

Spring Cr

Flint River

ALABAMA GEORGIA

FLORIDA

Map 

area

N

EXPLANATION

STREAM SEEPAGE—Hachures 

indicate net loss in stream 

discharge between stations

SURFACE-WATER MONITORING 

STATION AND MEASURED 

STREAM DISCHARGE—In 

cubic feet per second

LOWER APALACHICOLA–CHATTAHOOCHEE–FLINT RIVER BASIN

Base modified from 

U.S. Geological Survey

1:100,000-scale digital data 

88.4
Stream-aquifer relations and the potentiometric surface of the Stream-aquifer relations 13

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 7. Stream seepage along selected stream reaches in the 

lower Apalachicola–Chattahoochee–Flint River Basin, April 2000.

MITCHELL

BAKER

GRADY

DECATUR

SEMINOLE

MILLER

EARLY Newton

Donalsonville

Cairo

0

0

0

0

0

4,520

174

88.58

0.964

36.2

68.1

4,200

Bainbridge

Iron

City

Blakely

Pelham

Camilla

Colquitt

Elmodel Milford ALABAMA GEORGIA

FLORIDA

Map

area

Flint

River

Big

Slough

Fishpond Drain

Dry Cr

Spring Cr

Spring Cr

Aycocks Cr

Sawhatchee Cr

Lake

Seminole

0 10 20 MILES

0 10 20 KILOMETERS

Base modified from 

U.S. Geological Survey

1:100,000-scale digital data 

N

174

EXPLANATION

STREAM SEEPAGE—Hachures 

indicate net loss in stream 

discharge between stations

SURFACE-WATER MONITORING 

STATION AND MEASURED 

STREAM DISCHARGE—In 

cubic feet per second

LOWER APALACHICOLA–CHATTAHOOCHEE–FLINT RIVER BASIN

Table 4. Mean-annual percentage of total streamflow that is baseflow, by month, in selected streams in the 

lower Apalachicola–Chattahoochee–Flint River Basin, 1980–2000

Station name 

and number

Percent of mean-annual streamflow comprised of baseflow

Oct Nov Dec Jan Feb Mar Apr May June July Aug Sep

Spring Creek near Iron City, Ga.

02357000 57 70 66 63 65 61 63 68 68 64 64 64

Muckalee Creek at Ga. 195, near 

Leesburg, Ga. 02351890 68 70 68 64 60 62 67 59 57 37 60 60

Kinchafoonee Creek at Preston, Ga.

02350600 71 71 64 65 66 62 66 63 68 57 68 65

Turkey Creek at Byromville, Ga.

02349900 64 61 53 55 56 55 54 52 46 36 50 61
14 Stream-aquifer relations Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 8. Stream seepage along selected stream reaches in the 

lower Apalachicola–Chattahoochee–Flint River Basin, August 2000.

MITCHELL

BAKER

DECATUR GRADY

SEMINOLE

MILLER

EARLY

CALHOUN

RANDOLPH

CLAY

TERRELL

WORTH

SUMTER

LEE

DOOLY

DOUGHERTY

CRISP

MACON

WEBSTER

STEWART

SCHLEY

MARION

TURNER

COLQUITT

TAYLOR

HOUSTON CHATTAHOOCHEE

Bainbridge

Iron

City

Blakely

Newton

Pelham

Camilla

Edison

Albany

Leesburg

Warwick

Cordele

Byromville

Montezuma

Preston

Lumpkin

Ellaville

Buena

Vista

Fort 

Gaines

Arlington

Moultrie

Butler

Cusseta

Perry

Elmodel

Donalsonville

Morgan

Cairo

Sylvester

Ashburn

Dawson Cuthbert

Americus Vienna

Oakfield

Milford

Colquitt

1,610

0.702 5.21

1.02

0

0

0

0

0 0 0

0

1,400

22.4

22.4

0

0

0 0

0

0.48

69.8

8.17

36

45.1

13.2 36.9

9.84

13.7

4.36

1.43

20.9

5.04

158 (est.)

Big

Slough

Muckalee Cr

Chickasawhatchee Cr

Kiokee Cr

Long Br

Flint River

Ichawaynochaway Cr

Muckalee

Turkey Cr Pennahatchee Cr

Muckaloochee Cr

Flint

River

Dry Cr

Dry Cr

Big C y press C

Aycocks Cr

Sawhatchee Cr

Lilly Br

Spring Cr

Hogcrawl Cr

Kinchafoonee Cr

Cr

Lake

Seminole

Spring Cr

Flint River

0 10 20 MILES

0 10 20 KILOMETERS

N

ALABAMA GEORGIA

FLORIDA

Map 

area

EXPLANATION

STREAM SEEPAGE—Hachures 

indicate net loss in stream 

discharge between stations

SURFACE-WATER MONITORING 

STATION AND MEASURED 

STREAM DISCHARGE—In 

cubic feet per second

LOWER APALACHICOLA–CHATTAHOOCHEE–FLINT RIVER BASIN

Base modified from 

U.S. Geological Survey

1:100,000-scale digital data 
Stream-aquifer relations and the potentiometric surface of the Stream-aquifer relations 15

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

(A) October 1999

(B) August 2000

Base modified from U.S. Geological Survey

1:100,000-scale digital data 

Figure 9. Stream seepage along 

Muckalee Creek near Leesburg, Georgia, 

(A) October 1999 and (B) August 2000.

DOUGHERTY

WORTH

LEE

Albany

Leesburg

DOUGHERTY

WORTH

LEE

Albany

Leesburg

0

0

3 MILES

1 2 3 KILOMETERS

1 2

149

126

151

36

126

126

45.1

Muckalee Creek

Muckalee Creek

Flint

River

Flint

River

EXPLANATION

STREAM SEEPAGE—Hachures 

indicate net loss in stream 

discharge between stations

SURFACE-WATER MONITORING 

STATION AND MEASURED 

STREAM DISCHARGE—In 

cubic feet per second

LOWER APALACHICOLA– 

CHATTAHOOCHEE–FLINT 

RIVER BASIN

N

ALABAMA GEORGIA

FLORIDA

Map

area

Conceptual Model of StreamAquifer Flow System

The conceptual model of the hydrologic flow system 

(fig. 12) is based on previous works by Sever (1965), 

Hayes and others (1983), Miller (1986), Johnston and 

Bush (1988), Hicks and others (1987), Torak and 

McDowell (1995), Torak and others (1996), and Stewart 

and others (1999). These studies suggest that recharge to 

the Upper Floridan aquifer is mainly by infiltrated 

precipitation, especially in outcrop areas near the updip 

limit of the limestone units and in river valleys, where 

the overburden has been eroded away, leaving the 

limestone exposed at the land surface. The Upper 

Floridan aquifer is semiconfined above by an undifferentiated overburden of sand, silt, and clay, which at 

times can support a water table and slow the flow of 

water to the Upper Floridan aquifer; but often, flow from 

the overburden to the aquifer is relatively rapid. Regional 

ground-water flow is northwest to southeast; and near 

streams, discharge is toward the stream channel. 

Although the lithology of the Upper Floridan aquifer 

indicates the potential for direct hydraulic connection 

between the aquifer and surface-water features, sudden 

changes in river stage do not necessarily correspond to 

a rise in the ground-water level (Torak and others, 

1996). When the ground-water level is higher than that 

of the stream stage, the Upper Floridan aquifer 

discharges to the stream. Conversely, when the 

ground-water level is lower than that of the stream 

stage, the stream may discharge water to the aquifer. 

This relation depends on the hydraulic gradient 

between the aquifer water level and stream stage, and 

the permeability of the streambed in areas of diffuse 

discharge (Hicks and others, 1987). 
16 Stream-aquifer relations Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

(A) October 1999

(B) August 2000

Figure 10. Stream seepage along Spring 

Creek between Colquitt and Brinson, Georgia, 

(A) October 1999 and (B) August 2000.

Base modified from U.S. Geological Survey

1:100,000-scale digital data 

Brinson

Donalsonville

Colquitt

Brinson

Bainbridge

Bainbridge

Iron

City

Iron

City

Donalsonville

Colquitt

SEMINOLE

MILLER

DECATUR

SEMINOLE

MILLER

DECATUR

0

88.4

25.6

0.48

0.70

0.48

EXPLANATION

STREAM SEEPAGE—Hachures 

indicate net loss in stream 

discharge between stations

SURFACE-WATER MONITORING 

STATION AND MEASURED 

STREAM DISCHARGE—In 

cubic feet per second

LOWER APALACHICOLA– 

CHATTAHOOCHEE–FLINT 

RIVER BASIN

0

0

3 MILES

1 2 3 KILOMETERS

1 2

N

Spring Creek

Spring Creek

Flint River

Flint River

ALABAMA GEORGIA

FLORIDA

Map

area

Ground-Water Contribution to 

Streamflow (Baseflow)

Baseflow is that part of streamflow contributed solely 

by ground-water discharge. Baseflow of all streams in 

the study area is maintained by ground-water 

discharge from the Upper Floridan aquifer. In winter, 

the ground-water level in the Upper Floridan aquifer 

is high and ground water discharges to streams, 

resulting in high baseflow. As the ground-water level 

declines during late spring through fall, so does 

baseflow (fig. 13). During the 1986 drought, 

streamflow (baseflow) was reduced substantially but 

recovered quickly with the return of normal 

precipitation in the early 1990s. 

The extended drought of 1998–2000 reduced 

streamflow to record or near-record lows; in southwest 

Georgia, streamflow was less than 12 percent of 

normal (mean-annual) flow (fig. 14A, B). In May 

2000, drought conditions continued and streamflow 

conditions decreased to 12–24 percent of normal

streamflow, with some areas as low as 1–12 percent 

(fig. 14A). By August 2000, streamflow in almost the 

entire study area decreased to 1–12 percent of normal 

streamflow (fig. 14B). By April 2001, streamflow had 

returned to normal conditions throughout much of the 

State; but drought conditions returned in late spring 

and early summer 2001, and streamflow was once 

again below normal flow conditions (U.S. Geological 

Survey, Georgia Drought Watch, 2002). 
Stream-aquifer relations and the potentiometric surface of the Stream-aquifer relations 17

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

O JF MJ JA N D MA S

DISCHARGE, IN INCHES

Baseflow

Runoff

Figure 11. Mean-monthly baseflow and runoff 

for Muckalee Creek, Georgia, 1980–2000.

The ratio of 1999 mean-annual streamflow to longterm runoff indicates drought conditions as compared 

with normal streamflow conditions (fig. 14C). 

Although drought conditions during 1998–2000 had 

little affect on the long-term runoff of the lower ACF 

River Basin, streamflows were reduced by as much as 

99 percent (fig. 14A, B). When streamflows are 

reduced, the ratio between streamflow and long-term 

runoff increases (fig. 14C), and the areas with the 

greatest reduction in streamflow also showed the 

highest ratios of long-term runoff to streamflow. A 

high ratio indicates that to maintain normal streamflow 

conditions, contributions from sources other than 

ground-water discharge are present—including direct 

precipitation and, consequently, runoff. Decreased 

precipitation and runoff during the drought result in 

ground-water discharge to streams becoming the 

principal component of streamflow. During the 

drought, however, the ground-water level also 

declined, reducing ground-water discharge to stream 

channels, which further reduced streamflow.

The distribution of mean-daily streamflow at selected 

sites in the study area indicates low-flow conditions 

during most of 1999–2000 (fig. 15). Median streamflow in 2000 was well below mean-annual streamflows 

at each station, having a record in 2000, and even lower 

than those during the drought of 1986, with the 

exception of Kinchafoonee Creek near Preston, 

Georgia. Box plots were used to illustrate the range of 

daily values in recent years and identify years that 

represent high and low daily streamflow conditions 

(fig. 15). Plotting the October 1999 and April and 

August 2000 estimated baseflows allows comparison 

to mean-daily streamflow ranges. Baseflow measurements were below median streamflow in each year of 

available data (1980–2001) except for the drought year 

of 2000, during which April streamflows were at or 

above median streamflows for each streamgaging 

station, due to precipitation events. August 2000 

streamflows were consistently at or near the lower 

extreme of streamflows for each site (fig. 15).

Three methods were used to estimate ground-water 

seepage, or baseflow, of streams in the lower ACF 

River Basin: field measurements, linear regression 

analysis, and hydrograph separation. Field measurements of baseflow obtained during October 1999, April 

2000, and August 2000 were compared to the 

distribution of mean-daily streamflow at selected 

reaches (fig. 15), and with estimates from linear 

regression analysis and hydrograph separation. Baseflow estimates using these methods were compared and 

evaluated seasonally, as well as climatically, for 

conditions of drought and normal or above-normal 

rainfall to determine the best method for estimating 

baseflow. Unit-area discharge of ground water to 

stream channels was reduced as the water level in the 

aquifer declined. In 1994, unit-area discharge ranged 

from 0.60 (ft3

/s)/mi2 to 0.79 (ft3/s)/mi2; in 1999 and 

2000, unit-area discharge was reduced, ranging from 

0.13 (ft3

/s)/mi2 to 0.58 (ft3/s)/mi2 (table 3).

Studies by Cushing and others (1973), Pettyjohn and 

Henning (1979), Reynolds (1982), Stricker (1983), and 

Atkins and others (1996) have shown that a regression 

relation between mean-annual baseflow and flow 

duration can be developed to determine the flow 

duration that best estimates baseflow. Flow-duration 

curves graphically represent the percent of time meandaily discharges were equaled or exceeded during a 

specified period. For example, the Q90 flow-duration 

point is that streamflow rate equaled or exceeded 90 

percent of the time. To develop a statistically valid 

relation between baseflow and flow duration using 

regression, long-term data are required for a minimum 

of 10 sites. 
18 Stream-aquifer relations Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

? ?

80

80

80

Upper Floridan aquifer

Semiconfining unit

Undifferentiated

overburden

(residuum)

Tampa Limestone

Ocala Limestone

Lisbon Formation

Intermediate system

Sub-Floridan confining unit

NOT TO SCALE

80 WATER-LEVEL CONTOUR, IN FEET

EXPLANATION

GROUND-WATER-FLOW DIRECTION

 Section view

 Plan view

SURFACE-WATER-FLOW DIRECTION

Figure 12. Schematic diagram of the conceptual hydrologic flow system in the lower 

Apalachicola–Chattahoochee–Flint River Basin (modified from Torak and others, 1993).

0

5

10

15

20

25

30

35

40

198419861988199019921994199619982000

DEPTH TO WATER BELOW LAND

SURFACE, IN FEET

0

20,000

40,000

60,000

80,000

100,000

120,000

DISCHARGE, IN CUBIC

FEET PER SECOND

WELL 12L028 (Depth to water)

EXPLANATION

GAGE 02353000 (Discharge)

Figure 13. Comparison of 

water level in well 12L028 to 

streamflow at gage 02353000 

on the Flint River at Newton, 

Georgia, 1984–2000.

GADSDEN CO

SEMINOLE CO DECATUR CO

JACKSON CO

G A

F L

Brinson

Bainbridge

Fowltown

Recovery

Dellwood

Sneads

Reynoldsville

N

JIM 

WOODRUFF DAM
Stream-aquifer relations and the potentiometric surface of the Stream-aquifer relations 19

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 14. Statewide distribution of percent of normal streamflow for (A) May 2000 and

(B) August 2000; and (C) the ratio of 1999 mean-annual streamflow to long-term runoff.

0

0 20 40 KILOMETERS

20 40 MILES

(A) May 2000 streamflow (B) August 2000 streamflow

EXPLANATION

20 to 34

34 to 48

SURFACE-WATER MONITORING 

 STATION—1999 ratio of mean-annual 

 streamflow to long-term runoff

(C) 1999 streamflow ratio

34 to 65

EXPLANATION

N

SURFACE-WATER MONITORING STATION—Percent of normal streamflow

48 to 63

63 to 77

24 to 34 1 to 12 12 to 24

Base modified from U.S. Geological Survey

1:100,000-scale digital data
20 Stream-aquifer relations Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

EXPLANATION 

x

x

x

x

x

x

o

o

o

o

o

o

75th percentile

Median

25th percentile

Lower outside

Lower detached

Upper detached

Number of measurements

Upper outside

October 1999 streamflow

April 2000 streamflow

August 2000 streamflow

Mean-annual streamflow

Figure 15. Distribution of mean-daily 

streamflow for (A) Kinchafoonee Creek 

near Dawson, Georgia; (B) Flint River 

at Newton, Georgia; (C) Apalachicola 

River at Chattahoochee, Florida; and 

(D) Kinchafoonee Creek at Preston, 

Georgia. Daily discharge during each 

measurement period shown in relation 

to mean-annual streamflow (see plate 

1 for location).

o

o

o

o

oo

ooo

o

o

o

oo

o

o

o

o

o

o

o

oo

o

o

o

o o

ooo

o

xxx

x

xx

xx

x

xxx x

x

xx

xx

xxx

xxxx

xx

x

x

x

xxxx

x

xxxxx

x

x

xxx

x

x

x

xxx xxx

x

x

x

x

xx

x

x

x

x

x

x

x

x

x

x

x x x x

x

x

x

x

x

x

xx

x

x

x

x

x

x

x x

x

x

x x

x

x

x

x

x

xx

xx

x

x

x

xxx

xx

xx

x

xx

x

xx

x

xx

x

x x

x x

x

x

x

xxx

x

xx

x

x

xx

x

xx x

x

x

xxx

x

xx

x

x

x

x

xxxxxxxx

366365365365366365365365366365365365366273

10,000

100,000

19801981198219831984198519861987198819891990199119921993

DISCHARGE, IN CUBIC FEET PER SECOND

(C) Apalachicola River at

 Chattahoochee, Florida (02358000)

19861988199019921994199619982000

19851986198719881989199019911992199319941995199619971998199920002001

(D) Kinchafoonee Creek at 

 Preston, Georgia (02350600)

10

100

1,000

1

230364365331365365366365

365

365365366365364365366

10,000

366365365365366365365365366365365365366365365365366365365365366122

19821984198619881990199219941995199619971998199920002001

1,000

10,000

100,000

1980

(B) Flint River at Newton, Georgia (02353000)

100

1,000

10,000

36536536536636536536536636536536536636536536536691

DISCHARGE, IN CUBIC FEET PER SECOND

(A) Kinchafoonee Creek near

 Dawson, Georgia (02350900)

1987198919911993199519971999

1981198319851987198919911993
Stream-aquifer relations and the potentiometric surface of the Stream-aquifer relations 21

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Linear Regression Analysis

A linear regression analysis, similar to that performed 

by Stricker (1983), was used to develop a relation 

between mean-annual baseflow and flow duration for 

streams located in the lower ACF River Basin. Stricker 

(1983) developed a relation between flow duration and 

baseflow for streams in the outcrop areas of Cretaceous aquifers north of the study area, and showed that 

flow-duration curves having little slope indicate a 

uniform ground-water contribution to baseflow. 

Further, steeply sloped curves indicate that runoff is 

necessary to produce streamflow, with little or no 

baseflow (Stricker, 1983). 

The shape of a flow-duration curve can be described 

by the index:

Q25

Q75

-------

(1) ,

where, Q25 is the streamflow at the 25th percentile and 

Q75 is the streamflow at the 75th percentile; the smaller 

the index, the greater the portion of baseflow from 

ground water (Stricker, 1983). Whitewater Creek and 

Pataula Creek were shown to have index values of 

1.13 and 1.48, respectively, indicating a large baseflow 

component of streamflow (Stricker, 1983). Index 

values for sites hydraulically connected to the Upper 

Floridan aquifer range from 1.58 to 4.38 (table 5), 

higher than index values for sites hydraulically connected to Cretaceous aquifers. The relatively high 

index values for streams draining the Upper Floridan 

aquifer indicate a smaller percentage of total streamflow contributed by ground water than streams 

draining Cretaceous aquifers north of the study area. 

This is further evidenced by comparing flow-duration 

curves for the two site types (figs. 16 and 17). Turkey, 

Kinchafoonee, Muckalee, and Spring Creeks have 

relatively steeper curves (fig. 16) and higher index 

values than Whitewater and Pataula Creeks (fig 17), 

which are hydraulically connected to the 

Cretaceous aquifers.

Stricker (1983) reported that for streams interacting 

with Cretaceous aquifers north of the study area, the 

Q60 or Q65 discharges provided a reasonable estimate 

of baseflow. This can be seen graphically on the flowduration curve where the slope of the line is relatively 

small at or near Q60 or Q65 discharges (fig. 17). The 

variability of hydrologic properties of the Upper 

Floridan aquifer and the clayey residuum overlying it, 

the presence of springs in stream channels, and the 

direct connectivity of streams to the aquifer in areas 

where the residuum has been eroded, cause streamflow to be flashy, making the Q60 or Q65 discharges 

unreliable as estimates of baseflow. 

Spring Creek

FLOW DURATION, IN PERCENT

Muckalee

Creek

Kinchafoonee 

Creek Turkey

Creek

1

10

100

1,000

10,000

5 15 25 35 45 55 65 75 85 95

LOG DISCHARGE, IN CUBIC

FEET PER SECOND

Figure 16. Duration of mean-daily 

streamflow for selected sites in the lower 

Apalachicola-Chattahoochee-Flint 

River Basin that have a direct hydraulic 

connection to the Upper Floridan aquifer.

Pataula Creek

Whitewater Creek

1

10

100

1,000

10,000

5 15 25 35 45 55 65 75 85 95

LOG DISCHARGE, IN CUBIC

FEET PER SECOND

FLOW DURATION, IN PERCENT

Figure 17. Duration of mean-daily 

streamflow for selected sites that have a 

hydraulic connection to the Cretaceous 

aquifers (from Stricker, 1983).
22 Stream-aquifer relations Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Table 5. Flow-duration index for selected streams in the lower Apalachicola–Chattahoochee–Flint River Basin

[ft3/s, cubic foot per second]

Site 

number Station name

Index 

valuea

(ft3/s)

Meanannual 

baseflow

(ft3/s)

Meanannual 

discharge

(ft3/s)

Discharge 

composed of 

baseflow

(percent)

02343200 Pataula Creek near Lumpkin, Ga.b 1.48 62 87 71

02343801 Chattahoochee River near Columbia, Ala. 1.75 3,844 10,755 36

02349000 Whitewater Creek below Rambulette Creek near Butler, Ga.b 1.13 147 163 90

02349500 Flint River at Montezuma, Ga. 1.68 2,206 3,394 65

02349900 Turkey Creek at Byromville, Ga. 2.58 23 46 50

02350512 Flint River at Ga. 32, near Oakfield, Ga. 1.71 2,230 4,360 51

02350600 Kinchafoonee Creek at Preston, Ga. 1.75 136 210 64

02350900 Kinchafoonee Creek near Dawson, Ga. 1.92 348 532 65

02351890 Muckalee Creek at Ga. 195, near Leesburg, Ga. 1.88 247 392 63

02352500 Flint River at Albany, Ga. 1.70 3,464 6,151 56

02353000 Flint River at Newton, Ga. 1.67 4,064 6,451 63

02353400 Pachitla Creek near Edison, Ga. 1.58 160 248 65

02353500 Ichawaynochaway Creek at Milford, Ga. 1.65 525 761 69

02354500 Chickasawhatchee Creek at Elmodel, Ga. 4.38 161 260 62

02354800 Ichawaynochaway Creek near Elmodel, Ga. 1.77 646 968 67 

02355350 Ichawaynochaway Creek below Newton, Ga. 1.69 723 990 73

02357000 Spring Creek near Iron City, Ga. 2.53 313 505 62

a. Index values are computed as (Q25 / Q75)

0.5, where Q25 is the 25-percent flow duration and Q75 is the 75-percent flow duration.

b. Stream having interaction with Cretaceous aquifers, north of the study area (Stricker, 1983).

Linear regression analysis of flow-duration data from 

selected sites in the study area shows that the Q85 or 

Q90 flow duration (fig. 18) is the most reliable 

estimator of baseflow for the Upper Floridan aquifer 

(table 6). However, flows of Q85 or Q90 rarely occur 

during drought conditions; more typically, flows only 

reach Q95 or Q99 levels, which indicates a decrease in 

normal baseflow during drought conditions. Because 

the liner regression analysis is a comparison of meanannual baseflow and flow duration for several sites 

during many years, baseflow estimation by flow 

duration probably is representative of average climatic 

conditions. That is, the flow duration that satisfies the 

linear regression analysis may not represent baseflow 

or flow durations that occur during extreme climatic 

events such as drought.

Hydrograph Separation

Hydrograph separation was performed on streamflow 

data using HYSEP, a computer program that utilizes 

mathematical techniques to separate baseflow from 

streamflow (Sloto and Crouse, 1996). The mathematical formulation of HYSEP does not consider the 

geology of the basin; therefore, it can be used on a 

site-by-site basis in any hydrogeologic setting. The 

flexibility to apply HYSEP to any hydrogeologic 

setting, however, creates a limitation on its use, as it 

bases hydrograph separation only on basin area and 

streamflow hydrograph characteristics.

Estimates of baseflow using HYSEP were used to 

compare relative changes in baseflow contributions to 

streamflow on a seasonal and long-term basis. 
Stream-aquifer relations and the potentiometric surface of the Stream-aquifer relations 23

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Baseflow estimates are influenced by hydrologic 

properties, basin area, presence of impoundments, 

changing climate, antecedent conditions, and 

evapotranspiration. Seasonally, baseflow represented a 

higher percentage of total streamflow during fall and 

winter, when rainfall and runoff amounts are reduced, 

than during spring and summer, when rainfall is 

greater and surface runoff increases (table 4). Drought 

conditions during 1999 and 2000 increased the 

percentage of streamflow as baseflow (table 3). During 

1994, baseflow contributed from 37 to 56 percent of 

streamflow; during 1999 and 2000, baseflow ranged 

from 56 to 76 percent. Median baseflow contributions 

to the streams for the entire period of record at each 

site ranged from 54 to 67 percent. When used in this 

manner, hydrograph separation can illustrate the 

overall effect of drought on stream-aquifer relations. 

In general, less precipitation results in a reduction in 

runoff, causing baseflow to become a larger 

contributor to streamflow during drought.

Analysis of Baseflow Estimation 

Methods and Discussion of Error

Results of baseflow estimations by field measurements, linear regression analysis, and hydrograph 

separation were compared for each of the four selected 

streamgaging stations (table 7). Linear regression 

estimations tend to have higher error relative to 

HYSEP. In some instances, linear regression analysis 

proved to be an adequate method; but more often than 

not, baseflow estimations differed from field measurements by more than 30 percent (table 7). The hydrogeology of the lower ACF River Basin makes the 

errors associated with the linear regression analysis 

too large to prove useful. Hydrograph separation 

proved to be more useful in estimating relative 

differences between seasonal variations in groundwater discharge to streams than in providing accurate 

estimates of baseflow for any one period in time. 

Ground-water discharge, hence baseflow, is greatest 

during winter when evaporative demands and 

pumping needs are reduced. However, rainfall of long 

duration and moderate intensity infiltrates to recharge 

the aquifer, and eventually discharges to stream 

channels more in winter than in summer, when runoff 

is high from short-duration, high-intensity storms. 

Runoff accounts for a greater part of streamflow in 

summer than in winter (fig. 11). During the recent 

drought, however, there was little runoff, and 

streamflow comprised a higher proportion of groundwater discharge (table 3), which also was reduced as 

aquifer water level dropped. In comparison to field 

measurements, HYSEP adequately estimated 

baseflow; errors generally were less than 25 percent; 

but in a few instances, errors were larger than 40 

percent (table 7). There was no trend in terms of 

accumulation of error in a downstream direction, 

distance from recharge (outcrop) area, or magnitude of 

streamflow, although sites having smaller basin areas 

were more accurately estimated than those having 

larger basin areas.

Table 6. Coefficient of determination (r2) and 

residual standard error for flow durations evaluated as 

indicators of baseflow for selected sites in the lower 

Apalachicola–Chattahoochee–Flint River Basin

[P-value = less than 0.001, number of measurements = 16]

Flow

duration r-squared

Residual 

standard 

error

Q1 0.95 350.1

Q5 .91 452.4

Q10 .92 437.8

 Q15 .89 504.6

Q20 .90 476.2

Q25 .90 482.0

Q30 .89 494.1

Q35 .89 509.9

Q40 .88 526.8

Q45 .87 545.9

Q50 .86 564.2

Q55 .86 568.9

Q60 .86 567.7

Q65 .87 552.4

Q70 .90 487.6

Q75 .93 414.7

Q80 .95 331.3

Q85 .98a

a. Best estimate of baseflow.

205.4a

Q90 .99a 137.7a

Q95 .97 251.9

Q99 .97 285.6
24 Potentiometric surface Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 18. Comparison of mean-annual baseflow and discharge at the 85- and 90-percent duration points.

DISCHARGE AT 85-PERCENT DURATION

(Q85) IN CUBIC FEET PER SECOND

MEAN-ANNUAL BASEFLOW,

IN CUBIC FEET PER SECOND

0 1,000 2,000 3,000 4,000

0

1,000

2,000

3,000

4,000

0 1,000 2,000 3,000 4,000

DISCHARGE AT 90-PERCENT DURATION

(Q90) IN CUBIC FEET PER SECOND

r2 = 0.9917 r2 = 0.9918

POTENTIOMETRIC SURFACE

Potentiometric-surface maps for October 1999 and 

August 2000 illustrate the general direction of 

ground-water flow in the lower ACF River Basin 

(figs. 19 and 20, respectively). Distances between 

contour lines can be used to estimate the hydraulic 

gradients in a basin. Changes in the hydraulic 

gradients affect the rate and volume of ground-water 

contributions to streams and are indicated by the 

slope of the contour lines. Contour lines that are 

closely spaced indicate a steeply-sloping potentiometric surface, and therefore, a relatively rapid flow 

of ground water perpendicular to the contours. More 

widely spaced contour lines indicate a flatter potentiometric surface. In this case, ground water still moves 

in a direction perpendicular to the contour; however, 

the rate of ground-water flow is less than that for a 

steeply-sloping potentiometric surface. During each 

measurement period, the regional hydraulic gradient 

sloped from northwest to southeast except in the 

vicinity of streams, where local hydraulic gradients 

allowed ground water to discharge to stream channels 

independent of regional flow gradients.

Under normal conditions, hydraulic gradients in the 

lower ACF River Basin are steepest near stream 

channels and become flatter farther away from the 

streams. An example is shown on the May 1998 

potentiometric-surface map of Peck and others (1999) 

(fig. 21). The slope of the contour lines is steepest near 

stream channels; but south and east of the Flint River, 

the contour lines are more widely spaced, indicating a 

lower hydraulic gradient and a gentler slope. Drought 

conditions can also decrease these gradients and affect 

the rate at which ground water discharges to streams. 

During October 1999 and August 2000, water-level 

altitudes in the Upper Floridan aquifer declined, 

resulting in a lower regional hydraulic gradient and 

reduced baseflow to streams compared to that 

occurring during normal or wet periods (figs. 19 and 

20). In areas where the water level in the Upper 

Floridan aquifer fell below a stream channel, hydraulic 

gradients were established from the stream to the 

aquifer and streams lost water to the aquifer through 

streambed leakage. Although some stream reaches 

discharged water to the aquifer, throughout most of the 

study area, ground water continued to discharge to 

streams; that is, hydraulic gradients caused ground 

water to flow from the aquifer to the stream channel.
Upper Floridan aquifer

Stream-aquifer relations and the potentiometric surface of the Potentiometric surface 25

 in the lower ACF River Basin, 1999 – 2000

Table 7. Comparison of unit-area ground-water discharge estimates using field measurements of baseflow, hydrograph and regression techniques for selected streams in the lower Apalachicola

–Chattahoochee

–Flint River Basin, October 1

April and August 2000 [(ft3/s)/mi2 - cubic foot per second per square mile]

Station name

and number

Month

year

Field 

measurement

of baseflow

([ft3/s]/mi2)

HYSEP

([ft3/s]/mi2)

Q85

([ft3/s]/mi2)

Q90

([ft3/s]/mi2)

Error in 

HYSEP

estimation

Error in 

Q85

estimation

Error in 

Q90

estimation

Percen

error in 

HYSEP 

estimati

Turkey Creek near Byromville, Ga. 02349900

October 1999April 2000August 2000

0.13

.31.08

0.09

.38.07

0.12

.12.12

0.10

.10.10

-0.04

.07

-.01

-0.01

-.19

.04

-0.03

-.21

.02

-30.77

22.58

-12.50

Kinchafoonee Creek 

near Preston, Ga.02350600

October 1999April 2000August 2000

.34.39.12

.24.49.1

.30.30.30

.25.25.25

-.1

.1

-.02

-.04-.09

.18

-.09-.14

.13

-29.41

25.64

-16.67

Muckalee Creek at Ga. 

195, near Leesburg, Ga. 02351890

October 1999April 2000August 2000

.43.45.15

.25.52.07

.28.28.28

.23.23.23

-.18

.07

-.08

-.15-.17

.13

-.20-.22

.08

-41.86

15.56

-53.33

Spring Creek near 

Iron City Ga.02357000

October 1999April 2000August 2000

.08.17.001

.07.26.00

.15.15.15

.08.08.08

-.01

.09

-.001

.07

-.02

.15

.00

-.09

.08

-12.50

52.94

-100.00
26 POTENTIOMETRIC SURFACE Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 19. Generalized potentiometric surface of the Upper Florida aquifer in the lower Apalachicola–

Chattahoochee–Flint River Basin, October 1999.

Base modified from

U.S. Geological Survey

1:100,000-scale digital data

GA

FL

0 10 20 MILES

0 10 20 KILOMETERS

Lake

Seminole

EARLY

JACKSON

GADSDEN

SEMINOLE DECATUR

MILLER

BAKER

GRADY

CALHOUN DOUGHERTY

MITCHELL

WORTH

LEE

TERRELL

l l l l l l l l l l l l l l l l l l l l l l

l l l l l l l l l l l l l l l l l l l l

100

50

200

250

200

200

150

N

ALABAMA GEORGIA

FLORIDA

Map

area

100

MONITORING WELL, UPPER FLORIDAN AQUIFER

POTENTIOMETRIC CONTOUR—Shows altitude at which water level would 

have stood in tightly cased wells completed in the Upper Floridan aquifer 

during October 1999. Dashed where approximately located. Contour 

interval 10 feet. Hachures indicate depression. Datum is NAVD 88

LOWER APALACHICOLA–CHATTAHOOCHEE–FLINT RIVER BASIN

EXPLANATION
Stream-aquifer relations and the potentiometric surface of the POTENTIOMETRIC SURFACE 27

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 20. Generalized potentiometric surface of the Upper Floridan aquifer 

in the lower Apalachicola–Chattahoochee–Flint River Basin, August 2000.

N

Base modified from

U.S. Geological Survey

1:100,000-scale digital data

Lake

Seminole

GA

FL

200

100

250

150

EARLY

MILLER

BAKER

JACKSON

GADSDEN

SEMINOLE DECATUR GRADY

MITCHELL

WORTH

LEE TERRELL

CALHOUN DOUGHERTY

0 10 20 MILES

0 10 20 KILOMETERS

ALABAMA GEORGIA

FLORIDA

Map

area

100 POTENTIOMETRIC CONTOUR—Shows altitude at which water level 

would have stood in tightly cased wells completed in the Upper 

Floridan aquifer during August 2000. Dashed where approximately 

located. Contour interval 10 feet. Datum is NAVD 88

MONITORING WELL, UPPER FLORIDAN AQUIFER

EXPLANATION

LOWER APALACHICOLA–CHATTAHOOCHEE–FLINT RIVER BASIN
28 Potentiometric surface Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Figure 21. Potentiometric surface of the Upper Floridan aquifer in the lower Apalachicola–

Chattahoochee–Flint River Basin, May 1998 (modified from Peck and others, 1999).

100

150

250

300

200

N

GA

FL

Lake

Seminole

EARLY

MILLER

BAKER

JACKSON

GADSDEN

SEMINOLE DECATUR GRADY

CALHOUN

DOUGHERTY

MITCHELL

WORTH

LEE

TERRELL

0 10 20 MILES

0 10 20 KILOMETERS

APPROXIMATE POTENTIOMETRIC CONTOUR—Shows approximate 

altitude at which water level would have stood in tightly cased wells during 

May–June 1998. Contour interval 10 feet. Datum is NAVD 88

EXPLANATION

LOWER APALACHICOLA–CHATTAHOOCHEE–FLINT RIVER BASIN

Base modified from

U.S. Geological Survey

1:100,000-scale digital data

100

ALABAMA GEORGIA

FLORIDA

Map

area
Stream-aquifer relations and the potentiometric surface of the SUMMARY 29

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

SUMMARY

Stream-aquifer relations in the lower ACF River 

Basin were evaluated during drought conditions of 

1999–2000 to estimate rates of ground-water discharge. Ground-water discharge to selected streams 

was estimated using three methods: (1) field 

measurements of baseflow; (2) HYSEP, an automated 

hydrograph-separation computer program; and (3) a 

comparison of mean-annual baseflow and flowduration data using a simple linear regression analysis. 

HYSEP provided estimates of mean-annual baseflow, 

runoff, and flow duration for four tributaries of the 

Flint River in the study area. Although accurately 

estimating baseflow is difficult, HYSEP is useful for 

comparing seasonal differences in baseflow as well as 

long-term trends. Typically during winter, groundwater discharge is the largest component of 

streamflow; in summer, runoff becomes more 

important with the increased intensity and short 

duration of precipitation. Drought conditions changed 

the relative magnitudes of streamflow components by 

reducing ground-water levels (and baseflow) and 

limiting the amount of runoff due to the lack of 

precipitation. During 1999–2000, ground water was 

the largest component of streamflow, in some 

instances comprising as much as 76 percent of 

total streamflow.

The complex hydrogeology of the lower ACF River 

Basin results in many unique problems in assessing 

stream-aquifer relations. Commonly, the streambed is 

in direct connection with the Upper Floridan aquifer in 

areas where the residuum has been eroded. Clay 

layers, if present in the lower part of the residuum, 

retard the vertical leakage of water that recharges the 

Upper Floridan aquifer and reduce discharge to stream 

channels. However, evaluation of mean-annual baseflow and flow duration shows that, under normal 

conditions, streams in the study area are not entirely 

dependent on ground-water discharge for streamflow. 

In addition, flow-duration indices tended to be high, 

suggesting that streamflow in the study area is 

composed more of runoff than baseflow. Flowduration curves for selected sites in the study area are 

steeply sloped, suggesting that runoff constitutes a 

large percentage of streamflow under normal 

conditions; this is typical of sites having a clayey 

lithology. Linear regression analysis of streamflow 

data shows that baseflow can be estimated by flow 

duration at the 85- and 90-percent levels (Q85 or Q90). 

However, linear regression analysis proves to be less 

useful in the lower ACF River Basin than in other 

areas, especially where streams intersect the Upper 

Floridan aquifer. The unique hydrogeology of the 

basin provides too many problems for linear 

regression analysis to estimate baseflow accurately. 

The unconfined nature of the aquifer, large variation in 

aquifer thickness and hydraulic conductivity, abundance of springs discharging to streams, and the 

variability of aquifer water level in response to 

pumping and drought cause large errors in baseflow 

estimates in linear regression analysis.

Drought conditions reduced not only runoff 

contributing to streamflow, but also the contribution 

from ground-water discharge. Changes to groundwater levels on potentiometric-surface maps illustrate 

declining hydraulic gradients from the Upper Floridan 

aquifer to streams for May 1998 through August 2000. 

As the ground-water level declined, the volume of 

water discharging to stream channels decreased. 

Unit-area discharge to stream channels decreased to 

such low levels that, in some reaches, streams went 

dry; but more often than not, record-low streamflow 

occurred. In selected streams under normal 

precipitation conditions (1994), unit-area discharge 

ranged from 0.60–0.79 (ft3/s)/mi2

; in 1999, unit-area 

discharge declined to 0.24–0.58 (ft3/s)/mi2

; and, by 

2000, unit-area discharge had been reduced to 

0.13–0.33 (ft3/s)/mi2. Runoff also decreased due to 

lack of precipitation, increasing the contribution of 

baseflow to total streamflow. In selected streams, 

baseflow estimates increased from 37 percent to 

56 percent under normal conditions (1994), from 60 

percent to 73 percent in 1999, and from 56 percent to 

76 percent in 2000. This increased dependence of 

streamflow on ground-water contributions and the 

subsequent reduction of ground-water level and 

ground-water discharge reduced streamflows to 

record or near-record lows throughout the lower ACF 

River Basin.
30 REFERENCES CITED Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

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conditions on stream-aquifer flow in streams harboring 

federally protected mussel species, northwestern Florida and 

southwestern Georgia: Proceedings of the 2001 Georgia Water 

Resources Conference, Athens, Georgia, Kathryn J. Hatcher, 

editor, p. 129–130.

Atkins, J.B., Journey, C.A., and Clarke, J.S., 1996, Estimation of 

ground-water discharge to streams in the central Savannah 

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regional flow, and ground-water development of the Floridan 

aquifer system in Florida and in parts of Georgia, South 

Carolina, and Alabama: U.S. Geological Survey Professional 

Paper 1403-C, 80 p.

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resources of the Delmarva Peninsula: U.S. Geological 

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August 15th, 2002, at URL http://www.griffin.peachnet.edu/bae/.

Hayes, L.R., Maslia, M.L., and Meeks, W.C., 1983, Hydrology 

and model evaluation of the principal artesian aquifer, 

Dougherty Plain, southwest Georgia: Georgia Geologic Survey 

Bulletin 97, 93 p.

Hicks, D.W., Gill, H.E., and Longsworth, S.A., 1987, Hydrogeology, chemical quality, and availability of ground water 

in the Upper Floridan aquifer, Albany area, Georgia: U.S. 

Geological Survey Water-Resources Investigations Report 

87-4145, 52 p.

Johnston, R.H., and Bush, P.W., 1988, Summary of the hydrology 

of the Floridan aquifer system in Florida and in parts of 

Georgia, South Carolina, and Alabama: U.S. Geological Survey 

Professional Paper 1403-A, 24 p.

Miller, J.A., 1986, Hydrogeologic framework of the Floridan 

aquifer system in Florida and in parts of Georgia, Alabama, and 

South Carolina: U.S. Geological Survey Professional Paper 

1403-B, 91 p.

Mosner, M.S., 2001, Effects of drought on stream discharge and 

ground-water levels near Lake Seminole, southwestern Georgia 

and northwestern Florida, October 1999–August 2000: 

Proceedings of the 2001 Georgia Water Resources Conference, 

Athens, Georgia, Kathryn J. Hatcher, editor, p. 118–121.

Peck, M.F., Clarke, J.S., Ransom, Camille, III, and Richards, C.J., 

1999, 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: Georgia Geologic Survey Hydrologic Atlas 22, 

1 plate, scale 1:100,000.

Pettyjohn, W.A., and Henning, Roger, 1979, Preliminary estimate 

of ground-water recharge rates, related streamflow and water 

quality in Ohio: Ohio State University Water Resources Center 

Project Completion Report Number 552, 323 p.

Pratt, T.R., Richards, C.J., Milla, K.A., Wagner, J.R., Johnson, J.L., 

and Curry, R.J., 1996, Hydrogeology of the Northwest Florida 

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99 p.

Reynolds, R.J., 1982, Ground-water contribution of streams on 

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96-4040, 46 p.

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Water-Resources Investigations Report 99-4140, 42 p.

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90-4160, 67 p.
APPENDIX A.—WELLS MEASURED IN THE LOWER 

APALACHICOLA–CHATTAHOOCHEE–

FLINT RIVER BASIN, 1999–2000

Stream-aquifer relations and the potentiometric surface of the Appendix A 33

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Appendix A. Wells measured in the lower Apalachicola–Chattahoochee–Flint River Basin, 1999–2000

[—, no data]

USGS

site

name

Latitude

(North)

Longitude

(West)

Well 

deptha

Land

surface

altitudea

USGS 

site

name

Latitude

(North)

Longitude

(West)

Well

deptha

Land

surface

altitudeb

05H008 31°12'09" 85°00'33" 145 199 07F002 30°56'16" 84°49'58" 160 118

05J007 31°15'26" 85°00'08" 100 208 07F004 30°59'38" 84°46'53" — 113

06E001 30°49'05" 84°53'26" 180 127 07F006 30°52'58" 84°51'02" — 100

06E019 30°50'44" 84°54'38" 250 120 07G005 31°02'50" 84°47'27" 200 130

06E020 30°50'12" 84°53'25" 130 110 07G006 31°01'46" 84°48'39" 200 155

06E023 30°47'58" 84°55'13" 220 80 07G007 31°00'10" 84°49'48" 260 156

06F005 30°55'09" 84°55'23" 200 156 07G008 31°04'11" 84°45'06" — 152

06F007 30°53'09" 84°55'26" 250 162 07H005 31°07'47" 84°45'12" — 145

06F084 30°56'57" 84°55'48" 250 148 07H006 31°07'39" 84°47'17" — 140

06G006 31°04'27" 84°59'11" 123 152 07H007 31°09'01" 84°47'54" — 169

06G007 31°00'29" 84°59'18" 195 135 07H008 31°08'16" 84°50'18" — 175

06G008 31°03'31" 84°58'28" 140 132 07H009 31°07'43" 84°51'46" — 180

06G009 31°01'48" 84°55'47" 140 148 07H011 31°13'02" 84°52'29" — 181

06G012 31°00'48" 84°55'39" 170 190 07H012 31°11'13" 84°45'46" — 174

06H003 31°08'23" 84°54'59" 180 198 07H014 31°09'14" 84°51'09" — 172

06H006 31°08'14" 84°56'11" — 189 07J012 31°19'29" 84°46'42" — 187

06H008 31°10'55" 84°55'47" — 207 07J013 31°17'04" 84°47'40" — 180

06H009 31°11'08" 84°56'43" 160 202 08D001 30°44'50" 84°44'27" 140 255

06H012 31°11'28" 84°58'30" 205 192 08D002 30°44'15" 84°43'48" 340 285

06H013 31°08'00" 84°56'36" 150 185 08D003 30°44'08" 84°44'47" 300 250

07D001 30°44'20" 84°50'00" — 179 08D005 30°43'53" 84°42'42" — 276

07D002 30°44'54" 84°48'30" 200 182 08D006 30°42'47" 84°40'20" 380 290

07D004 30°43'57" 84°47′57" 120 127 08D007 30°44'56" 84°40'02" 300 300

07D005 30°43'56" 84°47'59" 150 159 08D090 30°44'54" 84°40'24" 340 293

07D006 30°43'16" 84°46'59" 340 272 08E002 30°51'17" 84°42'04" — 118

07E001 30°45'39" 84°46'03" 154 170 08E003 30°49'54" 84°42'26" — 100

07E003 30°45'08" 84°47'06" 174 189 08E005 30°49'28" 84°40'40" — 83

07E006 30°50'47" 84°52'13" 170 91 08E019 30°46'13" 84°43'43" 147 90

07E007 30°50'24" 84°47'35" 130 105 08E020 30°46'23" 84°43'38" 88 82

07E008 30°45'50" 84°45'45" 145 130 08E021 30°46'16" 84°43'12" 125 85

07E009 30°45'32" 84°45'08" 135 170 08E022 30°46'14" 84°43'14" 85 85

07E044 30°52'10" 84°45'19" 83 89 08E023 30°45'17" 84°43'32" 280 260

07E045 30°46'56" 84°49'35" 100 90 08E024 30°45'36" 84°43'41" 216 165

07E046 30°48'15" 84°47'26" 44 90 08E025 30°45'33" 84°38'32" 300 135

07E047 30°51'59" 84°46'02" 123 110 08E026 30°45'18" 84°44'22" 294 255
34 APPENDIX A Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

08E027 30°45'56" 84°42'16" — 205 09F005 30°56'51" 84°36'24" — 130

08E031 30°47'53" 84°38'51" 240 192 09F520 30°57'42" 84°35'46" 251 128

08E032 30°50'27" 84°37'35" 119 95 09F522 30°52'58" 84°37'05" 86 90

08E034 30°48'58" 84°42'47" — 107 09G004 31°06'24" 84°31'23" — 138

08E035 30°48'36" 84°44'22" 115 90 09G005 31°05'12" 84°35'31" — 152

08E037 30°51'57" 84°41'29" 97 125 09G006 31°07'04" 84°37'14" 220 158

08F006 30°58'48" 84°43'48" — 120 09G007 31°02'15" 84°32'52" — 142

08F009 30°53'26" 84°38'38" — 118 09G010 31°02'50" 84°34'21" 230 145

08F012 30°55'20" 84°39'15" — 115 09H001 31°09'05" 84°31'14" — 152

08F018 30°52'36" 84°44'07" 125 118 09H007 31°13'00" 84°37'09" — 189

08F499 30°52'58" 84°38'05" 120 100 09H009 31°14'16" 84°33'57" — 166

08G005 31°01'36" 84°41'17" — 130 09H011 31°12'36" 84°35'43" 195 175

08G006 31°00'25" 84°43'28" — 122 09H012 31°08'57" 84°33'27" 205 150

08H003 31°12'41" 84°44'25" — 148 09H014 31°13'35" 84°31'19" 200 152

08H005 31°14'10" 84°44'26" 165 175 09J004 31°18'22" 84°34'18" 245 204

08H006 31°12'36" 84°40'04" — 172 09J008 31°20'01" 84°31'14" — 157

08H007 31°14'41" 84°42'07" 200 190 09J009 31°15'45" 84°36'04" — 193

08H008 31°12'11" 84°43'37" — 160 09J010 31°17'49" 84°32'09" — 175

08H009 31°14'11" 84°40'33" — 193 09J012 31°21'38" 84°31'40" — 158

08H010 31°09'52" 84°40'48" 210 172 09K010 31°22'51" 84°37'17" — 195

08J004 31°21'07" 84°37'59" — 220 10D015 30°44'57" 84°29'01" — 315

08J005 31°21'11" 84°40'21" 100 230 10F001 30°59'50" 84°28'54" — 140

08J015 31°17'13" 84°44'32" 160 176 10G313 31°05'07" 84°26'22" 206 145

08K013 31°22'57" 84°38'17" 155 218 10H004 31°12'42" 84°29'25" — 152

08K016 31°22'31" 84°43'08" 260 232 10H006 31°08'04" 84°25'44" 200 158

09E003 30°52'23" 84°35'17" 75 115 10J002 31°16'21" 84°23'45" — 158

09E004 30°52'23" 84°35'13" 75 115 10J003 31°18'05" 84°23'36" — 173

09E005 30°52'22" 84°34'30" 80 120 10J004 31°18'43" 84°24'45" 140 180

09E006 30°51'32" 84°34'03" 225 110 10K004 31°22'51" 84°23'47" — 189

09E007 30°51'04" 84°34'02" 225 138 10K006 31°25'46" 84°28'58" 100 183

09E008 30°48'23" 84°33'30" 320 292 10L003 31°30'49" 84°27'19" — 222

09E009 30°47'50" 84°33'22" 360 300 10L004 31°35'32" 84°28'35" — 234

09E521 30°46'03" 84°36'47" 294 280 10L016 31°31'52" 84°27'56" — 229

09E522 30°52'28" 84°36'21" 105 100 10L018 31°31'53" 84°24'32" — 207

09F004 30°57'53" 84°30'22" — 119 10M003 31°38'18" 84°22'52" 176 268

Appendix A. Wells measured in the lower Apalachicola – Chattahoochee – Flint River Basin, 1999 – 2000—

Continued

USGS

site

name

Latitude

(North)

Longitude

(West)

Well 

deptha

Land

surface

altitudea

USGS 

site

name

Latitude

(North)

Longitude

(West)

Well

deptha

Land

surface

altitudeb
Stream-aquifer relations and the potentiometric surface of the Appendix A 35

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

10N012 31°45'30" 84°26'08" 103 333 12K009 31°25'38" 84°11'03" 160 180

11G002 31°04'31" 84°20'25" 250 140 12K113 31°25'52" 84°10'08" — 170

11G003 31°01'58" 84°18'16" — 182 12K115 31°28'48" 84°09'41" — 171

11H003 31°08'30" 84°21'55" — 149 12K120 31°29'04" 84°13'50" — 192

11J003 31°21'30" 84°20'16" — 169 12K130 31°26'21" 84°12'39" 94 185

11J004 31°22'05" 84°21'43" — 170 12K134 31°26'38" 84°10'26" — 184

11J005 31°18'32" 84°21'07" — 168 12K136 31°26'44" 84°12'37" 215 194

11J012 31°18'02" 84°19'23" 225 165 12L028 31°33'02" 84°12'00" 100 190

11J014 31°20'45" 84°20'19" — 174 12L045 31°36'58" 84°09'32" — 191

11J016 31°18'27" 84°16'18" 206 155 12L310 31°31'32" 84°13'32" 250 206

11J018 31°15'50" 84°17'47" 200 158 12M010 31°39'44" 84°09'01" 185 246

11J019 31°16'53" 84°18'24" 225 158 12M011 31°42'41" 84°10'37" 197 234

11J020 31°21'52" 84°18'05" 196 150 12M012 31°41'58" 84°08'12" 135 239

11K011 31°22'53" 84°20'05" — 173 12M013 31°40'00" 84°12'28" 158 230

11K016 31°24'18" 84°21'00" — 170 12M017 31°38'08" 84°09'36" 181 224

11K028 31°29'44" 84°20'45" 155 201 12M022 31°37'47" 84°08'07" 164 191

11K033 31°26'54" 84°21'01" 77 183 12M024 31°40'29" 84°11'00" — 232

11K043 31°29'13" 84°19'26" 170 193 12M027 31°41'53" 84°13'11" — 243

11L019 31°30'10" 84°18'49" — 179 12N004 31°52'28" 84°10'05" 200 289

11L020 31°33'00" 84°18'49" 150 207 12P010 31°54'16" 84°10'00" 185 300

11L077 31°33'48" 84°19'16" 130 210 13J001 31°17'29" 84°02'18" 431 375

11L111 31°33'40" 84°22'00" 125 220 13J004 31°21'29" 84°06'57" 208 194

11L112 31°36'14" 84°20'34" 180 232 13J006 31°19'18" 84°02'58" 206 247

11L115 31°35'54" 84°16'46" 150 220 13J008 31°21'05" 84°01'37" — 234

11L116 31°34'40" 84°18'14" 150 209 13K011 31°27'30" 84°03'43" 430 230

11M007 31°39'34" 84°20'36" 95 260 13K017 31°26'36" 84°03'46" 132 241

11M010 31°38'11" 84°17'20" 120 263 13K019 31°28'46" 84°07'19" — 195

11M017 31°42'10" 84°15'19" — 264 13K021 31°26'26" 84°02'06" 310 311

11M025 31°38'36" 84°21'04" 120 260 13K023 31°24'56" 84°00'19" 386 332

11M027 31°38'35" 84°21'06" — 259 13K091 31°26'01" 84°07'04" — 198

11P006 31°52'41" 84°16'06" 319 300 13L028 31°30'42" 84°02'09" 300 219

12H008 31°13'27" 84°12'56" 341 165 13L047 31°36'40" 84°00'21" 256 256

12J002 31°19'09" 84°11'15" 200 174 13L052 31°36'09" 84°04'35" 105 204

12K001 31°22'32" 84°09'38" 270 170 13L054 31°36'43" 84°02'17" — 206

12K008 31°25'22" 84°12'13" 195 193 13L057 31°33'47" 84°02'11" 150 227

Appendix A. Wells measured in the lower Apalachicola – Chattahoochee – Flint River Basin, 1999 – 2000—

Continued

USGS

site

name

Latitude

(North)

Longitude

(West)

Well 

deptha

Land

surface

altitudea

USGS 

site

name

Latitude

(North)

Longitude

(West)

Well

deptha

Land

surface

altitudeb
36 APPENDIX A Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

13M006 31°43'30" 84°00'51" 123 237 14L011 31°35'03" 83°58'52" — 257

13M011 31°40'08" 84°03'18" 160 260 14L013 31°30'27" 83°57'09" — 279

13M013 31°37'51" 84°05'36" 170 240 14L014 31°37'29" 83°55'03" — 283

13M027 31°42'52" 84°06'01" — 246 14L048 31°33'28" 83°59'58" 135 238

13M046 31°40'30" 84°06'00" 105 211 14M006 31°43'36" 83°57'28" — 260

13M049 31°40'15" 84°06'44" 110 241 14M008 31°43'06" 83°53'20" 102 288

13M050 31°41'36" 84°07'22" — 254 14P012 31°57'36" 83°59'14" — 294

13M051 31°42'56" 84°00'11" 245 244 14Q005 32°02'27" 83°56'45" 63 279

13M055 31°39'35" 84°02'10" 150 223 14Q006 32°01'57" 83°56'29" 175 277

13M056 31°41'34" 84°01'38" 173 254 14Q009 32°02'37" 83°53'22" — 320

13M060 31°43'46" 84°02'56" 165 267 15J015 31°21'54" 83°51'19" — 399

13M062 31°40'12" 84°04'43" 160 249 15K006 31°22'49" 83°50'35" 305 411

13M065 31°41'53" 84°05'45" 140 244 15K009 31°26'45" 83°52'28" — 409

13M066 31°43'45" 84°06'19" 120 259 15K010 31°29'20" 83°51'26" — 389

13M070 31°41'09" 84°05'55" — 247 15L007 31°30'40" 83°46'12" — 369

13M080 31°40'18" 84°03'25" 160 261 15L020 31°31'46" 83°49'16" 450 419

13M084 31°44'04" 84°01'22" 110 221 15L021 31°32'15" 83°50'45" 536 379

13M086 31°44'42" 84°03'45" 160 279 15L022 31°35'17" 83°49'49" — 435

13N003 31°48'09" 84°07'19" 160 289 15M004 31°41'23" 83°49'58" — 341

13N007 31°52'09" 84°04'24" 160 313 15M005 31°39'09" 83°49'12" — 322

13N009 31°52'05" 84°03'05" 115 299 15Q012 32°03'04" 83°51'56" 165 321

13P005 31°52'32" 84°04'19" 240 315 16J011 31°21'01" 83°43'44" 570 300

14J018 31°21'00" 83°57'34" — 389 16K011 31°24'05" 83°42'14" 620 358

14J019 31°21'57" 83°53'03" — 389 16K013 31°25'26" 83°42'35" 610 373

14J021 31°20'05" 83°55'53" — 375 16L019 31°30'45" 83°44'18" — 379

14J022 31°22'23" 83°56'03" — 417 16M008 31°39'18" 83°38'07" 375 388

14K006 31°29'30" 83°58'01" — 321 1370 30°44'31" 84°59'02" — —

14K008 31°23'58" 83°58'32" — 408 1640 30°53'13" 84°57'52" — —

14K009 31°28'59" 83°59'57" — 311 3339 30°31'09" 84°27'54" 96 201

14K011 31°28'02" 83°57'43" — 289 3340 30°31'09" 84°27'54" 356 200

14K012 31°28'46" 83°54'52" — 399 3341 30°31'09" 84°27'54" 27 199

14K013 31°25'50" 83°55'29" — 432 3342 30°31'09" 84°27'54" 435 200

14K015 31°25'23" 83°52'41" — 417 3375 30°31'24" 84°41'18" 432 248

14L005 31°35'17" 83°59'36" — 256 3558 30°32'43" 84°43'03" 803 250

14L006 31°34'00" 83°55'58" 235 331 3636 30°33'11" 84°42'34" 460 265

Appendix A. Wells measured in the lower Apalachicola – Chattahoochee – Flint River Basin, 1999 – 2000—

Continued

USGS

site

name

Latitude

(North)

Longitude

(West)

Well 

deptha

Land

surface

altitudea

USGS 

site

name

Latitude

(North)

Longitude

(West)

Well

deptha

Land

surface

altitudeb
Stream-aquifer relations and the potentiometric surface of the Appendix A 37

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

3653 30°33'19" 84°35'57" 396 225 5341 30°52'41" 85°07'59" 157 143

3692 30°33'37" 84°37'41" 250 230 5342 30°52'41" 85°12'42" 137 129

3785 30°34'18" 84°44'47" 420 275 5352 30°52'53" 85°10'05" 117 121

4026 30°35'49" 84°34'50" 701 151 5374 30°53'13" 85°01'36" 113 —

4040 30°35'54" 84°37'41" 660 279 5378 30°53'26" 85°05'26" 105 131

4102 30°36'20" 84°39'21" 467 289 5391 30°53'35" 85°02'35" 110 119

4318 30°38'13" 84°34'37" 460 265 5393 30°53'36" 85°08'39" 118 139

4421 30°39'19" 84°49'11" — — 5408 30°53'09" 85°01'39" 152 123

4541 30°40'33" 84°56'09" 122 — 5424 30°54'03" 85°11'07" 64 122

4566 30°40'55" 84°50'25" 214 121 5450 30°54'42" 85°13'48" 137 137

4577 30°41'05" 84°42'09" 469 — 5460 30°54'50" 85°04'54" 65 126

4607 30°53'30" 84°58'40" 105 100 5490 30°55'23" 85°07'05" 98 141

4647 30°42'04" 84°48'18" 355 — 5508 30°55'36" 85°09'45" 117 129

4677 30°42'30" 84°52'53" 210 — 5511 30°55'41" 85°08'21" 157 147

4681 30°42'29" 84°53'58" 101 99 5574 30°56'58" 85°14'30" 150 124

4795 30°44'12" 85°06'43" 210 167 5635 30°57'43" 85°07'22" 120 141

5062 30°47'45" 85°22'32" 280 134 5640 30°57'48" 85°12'06" 177 142

5147 30°49'18" 84°56'56" 200 100 5671 30°58'22" 85°09'56" 117 146

5151 30°49'18" 85°12'42" 152 107 5697 30°58'45" 85°07'03" 123 156

5226 30°50'25" 85°08'21" 118 129 5704 30°58'57" 85°06'48" 123 137

5266 30°51'12" 85°04'36" 158 128 5718 30°59'04" 85°06'33" 123 147

5288 30°51'37" 85°06'02" 80 123 6363 30°44'21" 84°56'09" 120 179

a. Well depth in feet below land surface.

b. Land surface altitude in feet above NAVD 88.

Appendix A. Wells measured in the lower Apalachicola – Chattahoochee – Flint River Basin, 1999 – 2000—

Continued

USGS

site

name

Latitude

(North)

Longitude

(West)

Well 

deptha

Land

surface

altitudea

USGS 

site

name

Latitude

(North)

Longitude

(West)

Well

deptha

Land

surface

altitudeb

APPENDIX B.—STREAMGAGING STATIONS 

MEASURED IN THE LOWER APALACHICOLA–

CHATTAHOOCHEE–FLINT RIVER BASIN, 1999–2000

Stream-aquifer relations and the potentiometric surface of the APPENDIX B 41

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Appendix B. Streamgaging stations measured in the lower Apalachicola–

Chattahoochee–Flint River Basin, 1999–2000

Station

number Station name Latitude(North)

Longitude

(West)

2343200 Pataula Creek near Lumpkin, Ga. 31°56'04" 84°48'12"

2343801 Chattahoochee River near Columbia, Ala. 31°15'34" 85°06'37"

2343940 Sawhatchee Creek at Cedar Springs, Ga. 31°10'41" 85°02'37"

2349000 Whitewater Creek below Rambulette Creek near Butler, Ga. 32°28'01" 84°15'58"

2349500 Flint River at Montezuma, Ga. 32°17'54" 84°02'38"

2349660 Sweetwater Creek at Andersonville, Ga. 32°11'10" 84°08'03"

2349740 Hogcrawl Creek (S-533) near Montezuma, Ga. 32°13'03" 83°59'30"

2349800 Flint River near Methvins, Ga. 32°07'29" 84°00'43"

2349900 Turkey Creek at Byromville, Ga 32°11'45" 83°54'03"

2349910 Turkey Creek (County Road) near Drayton, Georgia 32°06'14" 83°56'23"

2349960 Little Pennahatchee Creek near Lilly, Ga. 32°07'01" 83°51'44"

2349980 Pennahatchee Creek (County Road) near Drayton, Ga. 32°05'44" 83°55'04"

2350080 Lime Creek near Cobb, Ga 32°02'07" 83°59'33"

2350220 Gum Creek (U.S. Hwy. 280) at Coney, Ga. 31°57'41" 83°53'05"

2350300 Cedar Creek near Cordele, Ga. 31°54'46" 83°51'18"

2350360 Swift Creek near Warwick, Ga. 31°50'21" 83°51'18"

2350405 Flint River near Warwick, Ga. 31°50'57" 83°56'50"

2350509 Jones Creek near Oakfield, Ga. 31°45'34" 83°58'42"

2350512 Flint River at Ga. 32, near Oakfield, Ga. 31°43'31" 84°01'07"

2350524 Abrams Creek near Oakfield, Ga. 31°43'08" 83°59'19"

2350527 Mill Creek near Albany, Ga. 31°40'05" 83°59'48"

2350543 Piney Woods Creek above Albany, Ga. 31°36'09" 84°02'58"

2350600 Kinchafoonee Creek at Preston, Ga 32°03'10" 84°32'54"

2350860 Kinchafoonee Creek (Ga. 118) near Smithville, Ga. 31°52'07" 84°18'18"

2350900 Kinchafoonee Creek near Dawson, Ga. 31°45'53" 84°15'12"

2351000 Kinchafoonee Creek (Ga. Hwy. 32) near Leesburg, Ga. 31°43'11" 84°11'08"

2351500 Muckalee Creek near Americus, Ga. 32°05'00" 84°15'29"

2351700 Muckalee Creek near Smithville, Ga. 31°53'44" 84°11'52"

2351780 Muckaloochee Creek near Americus, Ga. 31°58'38" 84°18'12"

2351800 Muckaloochee Creek at Smithville, Ga. 31°54'20" 84°14'44"

2351890 Muckalee Creek at Ga. 195, near Leesburg, Ga. 31°46'35" 84°08'22"

2351900 Muckalee Creek near Leesburg, Ga. 31°43'56" 84°07'30"

2351930 Muckalee Creek below Leesburg, Ga. 31°39'06" 84°06'27"

2352500 Flint River at Albany, Ga. 31°35'40" 84°08'39"

2352760 Dry Creek near Putney, Ga. 31°27'05" 84°08'07"

2352790 Flint River (Putney Intake) near Putney, Ga. 31°26'40" 84°08'16"

2352920 Raccoon Creek at Ga. Hwy. 3 near Baconton, Ga. 31°21'49" 84°10'04"

2352970 Cooleewahee Creek near Albany, Ga. 31°30'14" 84°17'28"

2352980 Cooleewahee Creek near Newton, Ga. 31°19'49" 84°19'50"
42 APPENDIX B Stream-aquifer relations and the potentiometric surface of the

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

2353000 Flint River at Newton, Ga. 31°18'25" 84°20'19"

2353100 Ichawaynochaway C (U.S. Hwy. 82) near Graves, Ga. 31°46'17" 84°33'44"

2353200 Little Ichawaynochaway Creek near Shellman, Ga. 31°46'46" 84°36'13"

2353265 Ichawaynochaway Creek at Ga. 37, Near Morgan, Ga. 31°31'38" 84°34'58"

2353350 Carter Creek near Carnegie, Ga. 31°38'13" 84°43'14"

2353400 Pachitla Creek near Edison, Ga. 31°33'18" 84°40'43"

2353460 Ichawaynochaway Creek at State Rt. 62 near Leary, Ga. 31°28'10" 84°34'15"

2353500 Ichawaynochaway Creek at Milford, Ga. 31°22'59" 84°32'52"

2354300 Chickasawhatchee Creek near Dawson, Ga. 31°39'11" 84°25'46"

2354350 Chickasawhatchee Creek near Albany, Ga. 31°35'38" 84°27'12"

2354410 Chickasawhatchee Creek near Leary, Ga. 31°30'14" 84°25'50"

2354440 Kiokee Creek near Pretoria, Ga. 31°30'14" 84°22'01"

2354500 Chickasawhatchee Creek at Elmodel, Ga. 31°21'03" 84°28'57"

2354800 Ichawaynochaway Creek near Elmodel, Ga. 31°17'43" 84°29'17"

2355350 Ichawaynochaway Creek below Newton, Ga. 31°12'49" 84°28'24"

2355600 Big Cypress Creek near Newton, Ga. 31°12'15" 84°29'53"

2355660 Flint River near Camilla, Ga. 31°09'09" 84°28'57"

2355700 Flint River (Aux.) above Bainbridge, Ga. 30°57'16" 84°33'47"

2355785 Big Slough (SR 97) near Camilla, Ga. 31°13'07" 84°15'08"

2355830 Big Slough (SR 65) below Camilla, Ga. 31°09'03" 84°17'19"

2355880 Big Slough at Ga. 179 near Pelham, Ga. 31°05'25" 84°19'32"

2355950 Big Slough at Ga. Hwy. 97 near Bainbridge, Ga. 30°56'06" 84°31'23"

2356100 Spring Creek near Arlington, Ga. 31°24'48" 84°46'33"

2356220 Spring Creek at State Route 200 at Damascus, Ga. 31°18'21" 84°44'59"

2356290 Dry Creek near Blakely, Ga. 31°22'23" 84°52'59"

2356460 Dry Creek at Hentown, Ga. 31°17'03" 84°49'10"

2356600 Long Branch near Colquitt, Ga. 31°12'50" 84°43'54"

2356640 Spring Creek at U.S. 27, at Colquitt, Ga 31°10'15" 84°44'34"

2356970 Aycocks Creek below Colquitt, Ga. 31°06'20" 84°46'46"

2357000 Spring Creek near Iron City, Ga. 31°02'24" 84°44'18"

2357050 Spring Creek (U.S. Hwy. 84) at Brinson, Ga. 30°58'31" 84°44'44"

2357310 Fishpond Drain near Donalsonville, Ga. 30°58'45" 84°52'17"

2358000 Apalachicola River at Chattahoochee, Fla. 30°42'04" 84°51'33"

2358500 North Mosquito Creek at Chattahoochee, Fla. 30°42'09" 84°49'35"

2358519 Mosquito Creek at Chattahoochee, Fla. 30°41'20" 84°50'30"

Appendix B. Streamgaging stations measured in the lower Apalachicola – 

Chattahoochee –Flint River Basin, 1999 – 2000—Continued

Station

number Station name Latitude(North)

Longitude

(West)
APPENDIX C.—SPRINGS MEASURED IN THE 

LOWER APALACHICOLA–CHATTAHOOCHEE–

FLINT RIVER BASIN, 1999–2000
Stream-aquifer relations and the potentiometric surface of the APPENDIX C 45

Upper Floridan aquifer in the lower ACF River Basin, 1999 – 2000

Appendix C. Springs measured in the lower Apalachicola–

Chattahoochee–Flint River Basin,1999–2000

Spring Name Latitude

(North)

Longitude

(West)

Abrams Blue Hole 31°40'59" 83°55'41"

Blow Hole 31°32'47" 84°08'36"

Cow Pasture Spring 31°06'10" 84°30'28"

Crystal Cove Spring 31°25'42" 84°08'44"

Heli Hole 31°08'15" 84°28'59"

Hog Parlor 31°01'59" 84°30'43"

Mercer Mill Spring 31°41'03" 83°59'26"

New Hole 31°07'44" 84°29'15"

Punks Ramp Spring 31°23'24" 84°08'31"

Radium Spring 31°31'35" 84°08'12"

Vine Spring 31°24'43" 84°10'26"

Wall Spring 31°25'54" 84°08'35"