Water Withdrawals and Trends from the 

Floridan Aquifer System in the 

Southeastern United States, 1950-2000

By Richard L. Marella and Marian P. Berndt

A contribution of the National Water Quality Assessment (NAWQA) Program

U.S. Geological Survey Circular 1278

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2005

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Marella, R.L., and Berndt, M.P., 2005, Water withdrawals and trends from the Floridan aquifer system in the 

southeastern United States, 1950-2000: U.S. Geological Survey Circular 1278, 20 p.

Library of Congress Cataloging-in-Publication Data

Marella, Richard L.

 Water withdrawals and trends from the Floridan aquifer system in the Southeastern United States, 1950-2000 / 

by Richard L. Marella and Marian P. Berndt.

 p. cm. -- (U.S. Geological Survey circular ; 1278)

 Includes bibliographical references.

 ISBN 0-607-96885-0

 1. Water withdrawals--Gulf States. 2. Floridan Aquifer. I. Berndt, Marian P. II. Title. III. Series. 

 TD223.5.M37 2005

 333.91’0413’0975--dc22

 2005046390
iii

Contents

Introduction.....................................................................................................................................1

National Water-Quality Assessment Program..........................................................................2

Aquifer Description........................................................................................................................4 

Water Withdrawals, 2000 .............................................................................................................6

Water Withdrawal Trends, 1950-2000.......................................................................................14

Water Quantity and Quality Concerns......................................................................................16

References....................................................................................................................................19

Figures

1. Map showing general extent of the Floridan aquifer system ...............................1

2. Map showing location of principal aquifers selected for regional 

 assessment by the National Water-Quality Assessment Program

 study units......................................................................................................................3

3. Diagram showing sequence of aquifers in the southeastern 

 United States.................................................................................................................4

4. Map showing confinement of the Upper Floridan aquifer system.......................5

5. Chart showing water withdrawals from the Floridan aquifer 

 system by state, 2000 ...................................................................................................6

6. Chart showing water withdrawals from the Floridan aquifer 

 system by the largest public-water suppliers, 2000 ...............................................6

7. Chart showing percentage of water withdrawals from the 

 Floridan aquifer system by category, 2000 ...............................................................7

8. Map showing water withdrawals from the Floridan aquifer 

 system by county, 2000 ................................................................................................7

9. Map showing extent of the Floridan aquifer system in the 

 southeastern United States by county....................................................................13

 10. Chart showing total water withdrawals from the Floridan 

 aquifer system, 1950-2000 ........................................................................................14

 11. Graph showing water withdrawals from the Floridan aquifer 

 system by category, 1950-2000.................................................................................15

 12. Graph showing fluctuations of ground-water levels in selected wells 

 in the Upper Floridan aquifer....................................................................................16
iv

Tables

1. Water withdrawals from the Floridan aquifer system 

 by county, 2000..............................................................................................................8

2. Water withdrawals from the Floridan aquifer system by category, 

 1950-2000......................................................................................................................15

Conversion Factors and Datums

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square mile (mi2) 259.0 hectare (ha)

square mile (mi2) 2.590 square kilometer (km2) 

Flow rate

foot per year (ft/yr) 0.3048 meter per year (m/yr)

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s)

inch per year (in/yr) 25.4 millimeter per year (mm/yr)
Heading 1   

The Floridan aquifer system in the southeastern 

United States is one of the most productive aquifers in 

the world (Miller, 1990). This aquifer system underlies 

an area of about 100,000 square miles in southern 

Alabama, eastern and southern Georgia, southeastern 

Mississippi, southern South Carolina, and all of Florida 

(fig. 1). The Floridan aquifer system is the primary 

source of water for nearly 10 million people and 

supports agriculture, industry, and tourism throughout most of the region. In most areas, water from this 

aquifer is potable and needs very little treatment before 

use. However, in southern Florida (south of Lake 

Okeechobee), northwestern Florida and southern 

Alabama and Mississippi (Pensacola and westward), 

and eastern South Carolina, water in the aquifer system 

generally is not potable.

Introduction

Figure 1. General extent of the Floridan aquifer system. 

(Modified from Miller, 1990; and Aucott and others, 1986.)

Water from the Floridan aquifer system is generally 

potable and needs very little treatment before use. 

Dan Duerr, U.S. Geological Survey Richard Marella, U.S. Geological Survey

Irrigation well in Hillsborough County, Florida. 

Domestic household well in Putnam County, Florida.

The purpose of this report is to: 

• Provide a general description of the Floridan 

aquifer system; 

• Discuss water withdrawals by category for 2000; 

• Highlight trends in water withdrawals between 

1950 and 2000; and 

• Provide a brief summary on the effects that human 

impacts have on the Floridan aquifer system. 

Daytona

Beach

Atlantic

Ocean

Gulf of Mexico

Miami

FLORIDA

Tampa

St. Petersburg

Clearwater Lakeland

Orlando

Cocoa

Gainesville

EXTENT OF FLORIDAN

AQUIFER SYSTEM

ALABAMA MISSISSIPPI

Tallahassee

Birmingham

Pensacola Mobile

Jacksonville

Valdosta

Brunswick

Charleston

SOUTH

GEORGIA CAROLINA

Atlanta

Macon

Savannah

EXPLANATION

Lake

Okeechobee

0 100 200 MILES

0 100 200 KILOMETERS

Fort Myers

Hilton

Head

Albany

Naples
This report is a product of the U.S. Geological 

Survey (USGS) National Water-Quality Assessment 

Program regional synthesis of ground-water quality by 

principal aquifer study. The Floridan aquifer system is 

one of the principal aquifers in the United States selected 

for regional synthesis of ground-water quality and study 

between 2001-2010 (fig. 2). 

The National Water-Quality Assessment (NAWQA) 

Program is a primary source for long-term, consistent, 

nationwide information on the quality of ground water, 

streams, and aquatic ecosystems. The goals of NAWQA 

are to assess the status and trends of the water quality of 

the Nation and to understand the factors that affect water 

quality (Gilliom and others, 2001). Major aquifers and 

river basins define the 42 NAWQA study units 

(http://water.usgs.gov/nawqa). Within the individual 

study units, information on water chemistry, hydrology, 

National Water-Quality Assessment Program

land use, stream habitat, and aquatic life is collected 

and analyzed. Analysis at the study unit scale provides 

assessment of local factors that affect water quality. 

NAWQA data from the individual study units also are 

analyzed nationally to provide syntheses of the national 

occurrence and distribution of water quality. The large 

variability in hydrogeology throughout the Nation, 

however, commonly makes national assessment of 

ground-water quality challenging. For this reason, 

regional synthesis of ground-water quality by principal aquifer is an integral part of the NAWQA program 

during the second decade of studies (2001-2010). The 

Floridan aquifer system lies beneath five NAWQA 

study units—the Apalachicola-Chattahochee-Flint River 

Basins, the Georgia-Florida Coastal Plain Drainages, the 

Mobile River Basin, the Santee River Basin and Coastal 

Drainages, and the Southern Florida Drainages (fig. 2). 

Ginnie Springs (near Gainesville, Florida) is a popular swimming spot during the summer months. 

Stewart Tomlinson, U.S. Geological Survey

   Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000

About 800 springs discharge water from the Floridan aquifer system and many are used for recreation purposes. 
A

B

C

D

E

Cambrian-Ordovician aquifer system

Coastal Lowlands aquifer system

Floridan aquifer system

Surficial aquifer system

Biscayne aquifer

Northern Atlantic Coastal Plain aquifer system

Hawaiian volcanic-rock aquifers

Aquifers composed of glacial deposits

California Coastal Basin aquifers

Central Valley aquifer system

Denver Basin aquifer system

High Plains aquifer

Edwards-Trinity aquifer system

NAWQA Study Units overlying the Floridan aquifer system (outlined in red)

Basin and Range basin-fill and carbonate-rock aquifers1

Columbia Plateau basin-fill and basaltic-rock aquifers1

Snake River Plain basin-fill and basaltic-rock aquifers1

Piedmont and Blue Ridge crystalline-rock and carbonate-rock aquifers1

Mississippi embayment-Texas coastal uplands aquifer system1

New York and New England crystalline-rock aquifers

2

Referred to as the sand-and-gravel aquifer in Florida. 2

1 Combinations of principal aquifers.

Principal (or other) Aquifers

Georgia-Florida Coastal Plain Drainages

Source: Modified from U.S. Geological Survey, 2003

Santee River Basin and Coastal Drainages

Apalachicola-Chattahoochee-Flint River Basins Southern Florida Drainages

Mobile River Basin

E

D

C

B

A

EXPLANATION

3

Not considered principal aquifers (defined as regionally extensive aquifers or aquifer systems that have the 

 potential to be used as a source of potable water). The New York and New England crystalline rocks are, 

 in general, minimally permeable but contain locally productive aquifers that serve domestic supplies.

3

National Water-Quality Assessment Program 

Figure 2. Location of principal aquifers selected for regional assessment by the National Water-Quality Assessment Program 

(NAWQA) study units. The Floridan aquifer system lies beneath five NAWQA study units. 
The Floridan aquifer system is overlain by other 

aquifer systems in some areas that are used for local 

water supply. Leakage from these overlying aquifer 

systems recharges the Floridan aquifer system. These 

overlying aquifers include the surficial aquifer system, 

the intermediate aquifer system, the sand-and-gravel 

(Coastal Lowlands) aquifer, and the Biscayne aquifer 

(fig. 3). These aquifers are important sources of water 

supply locally. The sand-and-gravel aquifer is the major 

source of water in northwestern Florida (Pensacola area) 

and coastal Alabama (Mobile area); the Biscayne aquifer 

Aquifer Description

Figure 3. Sequence of aquifers in the southeastern United 

States. (Modified from Miller, 1990; Renken, 1998.)

Limestone quarry in Pasco County, Florida. 

Ann Tihansky, U.S. Geological Survey Harley Means, Florida Geological Survey

 Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000

The Floridan aquifer system is comprised of limestone and 

dolomite. In some places, it is close to the land surface.

Limestone quarry in Citrus County, Florida.

is the major source of water in southeastern Florida 

(Miami area); and the intermediate and surficial aquifers 

are the major sources of water in southwestern Florida 

(Fort Myers and Naples area).

The Floridan aquifer system is composed of a thick 

sequence of carbonate rocks (limestone and dolomite) of 

Tertiary age that range from late Paleocene to early 

Miocene. The aquifer system generally thickens toward 

the south from a thin edge near its northern limit in 

Georgia and South Carolina to more than 3,400 feet in 

ALABAMA

GEORGIA

SOUTH

CAROLINA

FLORIDA

Surficial aquifer system

Coastal Lowlands aquifer

system (referred to as

the sand-and-gravel

aquifer in Florida)

Biscayne aquifer

Intermediate aquifer

system

Floridan aquifer system

EXPLANATION

MISSISSIPPI
southern Florida (Miller, 1990). In most areas, the 

aquifer system is divided into three units: the Upper 

Floridan aquifer, the middle confining unit, and the 

Lower Floridan aquifer. The middle confining unit 

restricts the movement of water between the Upper and 

Lower Floridan aquifers. Throughout most of its extent, 

the Upper Floridan aquifer is overlain by a sequence of 

sand, clay, and limestone, that ranges in thickness from 

a few feet in parts of west and north-central Florida to 

hundreds of feet in southeastern Georgia, northeastern Florida, and the westernmost part of the Florida 

Panhandle. The sand generally comprises the surficial 

aquifer system, and the clay and limestone generally 

comprise the intermediate aquifer system, both of which 

are confining units to the Upper Floridan aquifer because 

they are less permeable than the Upper Floridan. The 

Upper Floridan aquifer is unconfined in western parts of 

north-central Florida, from north of Tampa to south of 

Tallahassee and in the Albany, Georgia, area southward 

into parts of Alabama and Florida (fig. 4). In some areas 

in southern Florida, the Upper Floridan aquifer is being 

used for the storage of freshwater (from surface water 

and the surficial aquifer system) for later recovery and 

use (Reese, 2002).

Recharge to the Upper Floridan aquifer occurs 

primarily in unconfined or semiconfined (fig. 4) welldrained upland areas characterized by poorly developed 

stream drainage and many closed depressions (sinkholes). Areas of high recharge (10 to 25 inches per year; 

Bush and Johnston, 1988; Sepúlveda, 2002) are present 

in west-central, northern, and western Florida, and in 

southwestern Georgia. Areas of low recharge (1 inch 

per year or less; Bush and Johnston, 1988) are present 

in northeastern Florida and southeastern Georgia, where 

confining units are greater than 100 feet thick.

Natural discharge from the Upper Floridan aquifer 

occurs throughout Florida and Georgia, most commonly 

through springs. A spring is formed when the ground 

water, which is under pressure, flows out through a 

natural opening in the ground. Florida has 33 firstmagnitude springs (discharge greater than 100 cubic feet 

per second or 64.6 million gallons per day), more than 

any other State (Scott and others, 2004). About 

800 springs have been identified within the Floridan 

aquifer system, 90 percent of which (about 720 springs) 

are in Florida (Scott and others, 2004). Cumulative 

discharge from these springs has been estimated at 

Figure 4. Confinement of the Upper Floridan aquifer system. 

(Modified from Miller, 1990.)

CONFINEMENT OF THE

UPPER FLORIDAN AQUIFER

Not determined

Unconfined

Semiconfined

Confined

FLORIDA

0 100 200 MILES

0 100 200 KILOMETERS

EXPLANATION

ALABAMA

GEORGIA

SOUTH CAROLINA MISSISSIPPI

FLORIDA

Tampa

Tallahassee

Albany

nearly 8 billion gallons per day (Bush and 

Johnston, 1988). Water discharged from 

springs provides or augments streamflow 

throughout central and northern Florida and 

southern Georgia. Several springs discharge 

offshore into the Atlantic Ocean or the Gulf 

of Mexico (Scott and others, 2004). Many 

springs are used for recreational purposes. 

Because it is deeply buried and in many 

places contains poor-quality water, the Lower 

Floridan aquifer has not been intensively 

drilled or tested, so its geologic character is 

not well known. Ground-water flow in the 

Lower Floridan aquifer is considered sluggish 

except where it is directly connected to the 

Upper Floridan aquifer (Miller, 1986). Some 

of the thick, low- and high-permeability units 

within the Lower Floridan aquifer are used 

in southern Florida for wastewater disposal, 

whereas some units in central and northern 

Florida are used as a potable water source. 

The Lower Floridan aquifer is being developed as a possible water source in many other 

areas of Florida and Georgia. 

Aquifer Description   
An estimated 4,020 million gallons per day 

(Mgal/d) of water was withdrawn from the 

Floridan aquifer system in 2000. Nearly 78 percent 

(3,125 Mgal/d) of this water was withdrawn in Florida 

(Marella, 2004) (fig. 5). Lesser amounts were withdrawn in Georgia (825 Mgal/d) (Fanning, 2003), South 

Carolina (63 Mgal/d) (Whitney Stringfield, U.S. 

Geological Survey, written commun., January 2003), 

and Alabama (7 Mgal/d) (Will Mooty, U.S. Geological 

Survey, written commun., March 2003). No water withdrawals were reported from the Floridan aquifer system 

in Mississippi during 2000 (David Burt, U.S. Geological 

Survey, written commun., October 2004). 

About 90 percent of the water withdrawn from the 

Floridan aquifer system was obtained from the Upper 

Floridan aquifer, which contains potable water in most 

areas. Localized contamination of the Upper Floridan 

aquifer, however, has forced water suppliers to obtain 

water from the Lower Floridan aquifer. In central and 

northeastern Florida, water from the Lower Floridan is 

potable, but in most other areas the water does not meet 

national drinking water standards because of high 

chloride concentrations (Berndt and others, 1998b).

The Floridan aquifer system is the primary source 

of drinking water for most cities in central and northern 

Florida, including Daytona Beach, Gainesville, Jacksonville, Lakeland, Orlando, St. Petersburg, Tallahassee, and 

Tampa. The aquifer system also is the primary drinking water source for most cities in eastern and southern 

Georgia, including Brunswick, Savannah, and Valdosta. 

An estimated 8.2 million people obtained drinking water 

from public-water supplies derived from the Floridan 

aquifer system in 2000. Another 1.6 million people 

obtained their drinking water from domestic wells that 

tap this aquifer system.

Nine public-water suppliers each withdrew 

more than 20 Mgal/d of water from the Floridan 

aquifer system in 2000 (fig. 6). Tampa Bay Water, the 

Figure 5. Water withdrawals from the Floridan aquifer 

system by state, 2000. (Fanning, 2003; Marella, 2004.)

Water Withdrawals, 2000

Figure 6. Water withdrawals from the Floridan aquifer system 

by the largest public-water suppliers, 2000.

FL GA AL / SC

3,500

3,000

2,500

2,000

1,500

1,000

500

0

WATER WITHDRAWALS,

IN MILLION GALLONS PER 

DAY

2000

200

160

120

80

40

0

Tampa Bay Water

Orlando Utilities

Commission

City of Jacksonville

Orange County

Utilities

City of Tallahassee

Lakeland Utilities

Cocoa

Water

Department

Gainesville

Regional Utilities

City of Savannah,

Georgia

WATER WITHDRAWALS, IN

MILLION GALLONS PER 

DAY

   Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000
Figure 8. Water withdrawals from the Floridan aquifer system by 

county, 2000. (Fanning, 2003; Marella, 2004.)

Figure 7. Water withdrawals from the Floridan aquifer 

system by category, 2000. 

largest water supplier using the Floridan aquifer system 

in 2000, withdrew nearly 200 Mgal/d of ground water 

(plus 80 Mgal/d of surface water) to supply more than 

1.7 million people in the Tampa Bay area (Southwest 

Florida Water Management District, 2002). Tampa Bay 

Water supplies the cities of Clearwater, St. Petersburg, 

and Tampa and many other public water systems in 

Hillsborough, Pasco, and Pinellas Counties, Florida. 

Other water suppliers withdrawing large amounts of 

water from the Floridan aquifer system include Orlando 

Utilities Commission in Orange County, Florida 

(100 Mgal/d), and Jacksonville Electric Authority (City 

of Jacksonville) in Duval County, Florida (95 Mgal/d) 

(St. Johns River Water Management District, 2004). 

Irrigation (1,949 Mgal/d; 49 percent) and public 

supply (1,329 Mgal/d; 33 percent) were the two largest categories of withdrawal from the Floridan aquifer 

system and accounted for about 82 percent of the water 

withdrawn in 2000 (fig. 7). The irrigation category 

includes water used for agriculture crop irrigation, livestock, and golf course irrigation. Industrial (including 

commercial, mining and power generation) and domestic 

self-supplied withdrawals in 2000 were 

576 Mgal/d (14 percent) and 166 Mgal/d 

(4 percent), respectively. Throughout most 

of Alabama, Florida, Georgia, and South 

Carolina, 2000 was an extremely dry year 

with drought conditions (University of 

Nebraska, 2004) resulting in higher-thannormal water demands for all irrigation 

purposes (agriculture crops, golf courses, 

and residential lawns).

Ten counties in Florida (Brevard, 

DeSoto, Duval, Highlands, Hillsborough, 

Manatee, Orange, Osceola, Pasco, and Polk) 

each withdrew more than 100 Mgal/d from 

the Floridan aquifer system (fig. 8), and 

accounted for more than 40 percent 

(1,683 Mgal/d) of the total water withdrawn 

in 2000. The largest withdrawals in 2000 

were in Polk (318 Mgal/d) and Orange 

(280 Mgal/d) Counties, Florida (table 1). 

Figure 9 shows the Floridan aquifer system 

in the southeastern United States by county.

Water Withdrawals, 2000   

Lake

Okeechobee

2000 TOTAL WATER

WITHDRAWALS,

in million gallons per day

0 to 1

1 to 10

10 to 50

50 to 100

greater than 100

Hillsborough

Pasco

Orange

Brevard

Osceola

Highlands

Polk

Manatee

DeSoto

Duval

Gulf of Mexico

Atlantic

Ocean

0 100 200 MILES

0 100 200 KILOMETERS

EXPLANATION

Extent of the

Floridan aquifer

system

Irrigation2

49 percent

(1,949 Mgal/d)

Industrial114 percent

(576 Mgal/d)

Domestic

self-supplied

4 percent (166 Mgal/d)

Public supply

33 percent

(1,329 Mgal/d)

1

2

Includes commercial, mining, and power generation.

Includes agricultural irrigation, livestock, and

golf course irrigation.
Water withdrawals, in million gallons per day

State and County

 Public 

 supply

 Domestic 

 self-supplied Industrial1 Irrigation2 Totals

Alabama

Baldwin 0.00 0.00 0.00 0.00 0.00

Choctaw 0.00 0.00 0.00 0.00 0.00

Clarke 0.00 0.00 0.00 0.00 0.00

Conecuh 0.05 0.00 0.00 0.00 0.05

Covington 0.42 0.14 0.00 0.00 0.56

Escambia 0.00 0.00 0.00 0.00 0.00

Geneva 0.00 0.46 0.00 0.00 0.46

Houston 0.31 0.95 0.00 4.91 6.17

Mobile 0.00 0.00 0.00 0.00 0.00

Monroe 0.00 0.00 0.00 0.00 0.00

Washington 0.00 0.00 0.00 0.00 0.00

Florida

Alachua 28.26 3.70 5.13 22.07 59.16

Baker 0.88 1.70 0.43 2.94 5.95

Bay 6.28 1.81 1.19 2.74 12.02

Bradford 1.38 1.70 1.25 1.27 5.60

Brevard 6.73 1.70 1.24 113.88 123.55

Broward 0.09 0.00 0.00 0.00 0.09

Calhoun 0.75 0.84 0.00 2.66 4.25

Charlotte 0.00 0.00 0.07 7.25 7.32

Citrus 13.97 6.50 2.35 6.53 29.35

Clay 14.77 3.82 6.87 7.51 32.97

Collier 2.84 0.00 0.00 1.53 4.37

Columbia 3.67 3.37 0.34 6.13 13.51

DeSoto 4.49 0.05 0.03 105.44 110.01

Dixie 0.67 0.90 0.26 1.59 3.42

Duval 119.12 1.12 20.84 8.92 150.00

Escambia 0.00 0.00 0.00 0.00 0.00

Flagler 2.31 0.56 0.20 17.51 20.58

Franklin 1.92 0.17 0.00 0.14 2.23

Gadsden 3.06 1.67 0.92 3.10 8.75

Gilchrist 0.27 1.20 0.26 13.97 15.70

Glades 0.55 0.00 0.14 6.96 7.65

Gulf 0.96 0.30 0.90 0.41 2.57

Hamilton 0.95 0.67 34.39 5.53 41.54

Hardee 1.78 0.06 6.66 73.23 81.73

Table 1. Water withdrawals from the Floridan aquifer system by county, 2000.

[Compiled by the U.S. Geological Survey, Tallahassee. General county locations are shown on figure 9. No water was reported 

withdrawn from the Floridan aquifer system in Mississippi during 2000]

   Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000
Table 1. Water withdrawals from the Floridan aquifer system by county, 2000.--Continued

[Compiled by the U.S. Geological Survey, Tallahassee. General county locations are shown on figure 9. No water was reported 

withdrawn from the Floridan aquifer system in Mississippi during 2000]

Water Withdrawals, 2000   

Water withdrawals, in million gallons per day

State and County

 Public 

 supply

 Domestic 

 self-supplied Industrial1 Irrigation2 Totals

Florida

Hendry 0.25 0.00 0.00 0.00 0.25

Hernando 20.26 1.27 19.70 8.09 49.32

Highlands 9.14 0.09 0.58 123.96 133.77

Hillsborough 85.51 3.99 14.17 91.19 194.86

Holmes 1.38 1.22 0.00 1.04 3.64

Indian River 8.03 1.68 0.00 64.30 74.01

Jackson 2.46 2.90 1.80 14.39 21.55

Jefferson 0.72 0.76 0.20 6.63 8.31

Lafayette 0.20 0.55 0.20 5.77 6.72

Lake 39.92 3.86 10.44 36.21 90.43

Lee 15.9 0.00 0.00 3.50 19.40

Leon 35.7 3.86 2.86 2.51 44.93

Levy 2.16 3.55 0.06 22.27 28.04

Liberty 0.39 0.40 0.82 0.16 1.77

Madison 1.65 1.11 0.15 6.03 8.94

Manatee 13.87 0.02 0.38 103.98 118.25

Marion 27.99 14.78 2.08 21.19 66.04

Martin 2.82 0.00 1.05 1.92 5.79

Miami-Dade 0.00 0.00 3.68 0.00 3.68

Monroe 0.00 0.00 0.14 1.23 1.37

Nassau 6.81 0.87 32.46 3.48 43.62

Okaloosa 22.97 1.14 4.14 3.77 32.02

Okeechobee 0.00 0.15 0.14 47.47 47.76

Orange 211.76 7.94 24.97 35.81 280.48

Osceola 30.00 4.15 0.87 79.63 114.65

Palm Beach 6.34 0.00 0.11 0.00 6.45

Pasco 102.67 4.05 4.86 27.66 139.24

Pinellas 39.88 0.37 0.09 2.82 43.16

Polk 75.43 9.36 74.05 158.91 317.75

Putnam 3.20 4.49 19.83 12.33 39.85

St. Johns 10.82 1.72 0.01 34.14 46.69

St. Lucie 5.65 0.74 0.00 40.59 46.98

Santa Rosa 3.73 0.20 0.00 5.10 9.03

Sarasota 17.21 0.01 0.25 9.76 27.23

Seminole 66.90 2.46 0.08 18.76 88.20
Table 1. Water withdrawals from the Floridan aquifer system by county, 2000.--Continued

[Compiled by the U.S. Geological Survey, Tallahassee. General county locations are shown on figure 9. No water was reported 

withdrawn from the Floridan aquifer system in Mississippi during 2000]

10 Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000

Water withdrawals, in million gallons per day

State and County

 Public 

 supply

 Domestric 

self-supplied Industrial1 Irrigation2 Totals

Florida

Sumter 4.44 4.11 0.36 17.43 26.34

Suwannee 1.40 2.43 1.60 20.71 26.14

Taylor 1.73 0.86 42.15 1.96 46.70

Union 0.36 0.99 0.40 1.05 2.80

Volusia 54.90 2.72 1.03 38.07 96.72

Wakulla 2.19 1.44 0.68 0.48 4.79

Walton 7.35 0.15 0.92 2.07 10.49

Washington 1.16 1.28 0.22 1.52 4.18

Georgia

Appling 1.05 0.82 0.17 2.44 4.48

Atkinson 0.42 0.26 0.16 2.34 3.18

Bacon 0.49 0.47 0.28 3.17 4.41

Baker 0.25 0.24 0.00 38.31 38.80

Ben Hill 4.21 0.55 0.00 3.60 8.36

Berrien 0.80 0.60 0.18 6.93 8.51

Bleckley 0.37 0.17 0.01 2.16 2.71

Brantley 0.39 0.95 0.00 0.18 1.52

Brooks 1.61 0.65 0.00 2.67 4.93

Bryan 1.56 0.63 0.00 0.05 2.24

Bulloch 3.41 1.24 1.33 6.49 12.47

Burke 0.00 0.00 0.78 0.00 0.78

Calhoun 0.00 0.00 0.00 0.00 0.00

Camden 3.75 0.99 37.21 0.66 42.61

Candler 0.66 0.40 0.00 2.23 3.29

Charlton 0.71 0.55 0.00 0.12 1.38

Chatham 33.45 2.23 31.50 5.81 72.99

Clinch 0.53 0.25 0.00 0.73 1.51

Coffee 5.44 1.36 0.00 5.45 12.25

Colquitt 4.45 1.58 0.53 11.27 17.83

Cook 2.15 0.51 0.00 5.19 7.85

Crisp 0.18 0.42 0.00 4.40 5.00

Decatur 2.65 1.11 0.92 50.52 55.20

Dodge 1.11 0.77 0.06 1.00 2.94

Dooly 0.00 0.00 0.00 0.00 0.00

Dougherty 0.06 0.00 8.17 5.08 13.31

Early 0.00 0.00 0.00 0.00 0.00
Table 1. Water withdrawals from the Floridan aquifer system by county, 2000.--Continued

[Compiled by the U.S. Geological Survey, Tallahassee. General county locations are shown on figure 9. No water was reported 

withdrawn from the Floridan aquifer system in Mississippi during 2000]

Water Withdrawals, 2000 11

Water withdrawals, in million gallons per day

State and County

 Public 

 supply

 Domestic 

 self-supplied Industrial1 Irrigation2 Totals

Georgia

Echols 0.06 0.25 0.00 5.76 6.07

Effingham 1.91 0.96 2.19 0.23 5.29

Emanuel 1.50 0.36 0.00 1.27 3.13

Evans 0.59 0.10 1.50 1.04 3.23

Glynn 12.42 0.65 49.80 0.00 62.87

Grady 1.98 0.83 0.00 6.25 9.06

Houston 0.00 0.00 0.00 0.00 0.00

Irwin 0.76 0.45 0.00 6.33 7.54

Jeff Davis 0.83 0.48 0.35 2.81 4.47

Jefferson 0.39 0.00 0.00 2.36 2.75

Jenkins 0.27 0.17 0.01 1.98 2.43

Johnson 0.18 0.21 0.00 0.81 1.20

Lanier 0.56 0.33 0.00 1.41 2.30

Laurens 0.27 0.51 0.00 2.15 2.93

Lee 0.00 0.00 0.00 0.00 0.00

Liberty 6.28 0.86 10.00 0.09 17.23

Long 0.27 0.48 0.00 0.09 0.84

Lowndes 9.30 2.00 10.89 7.42 29.61

Macon 0.00 0.00 0.00 0.00 0.00

McIntosh 0.87 0.15 0.03 0.01 1.06

Miller 0.30 0.30 0.00 30.25 30.85

Mitchell 2.58 0.42 0.00 29.00 32.00

Montgomery 0.48 0.21 0.00 1.12 1.81

Pierce 0.69 0.80 0.00 6.03 7.52

Pulaski 0.10 0.13 0.76 3.96 4.95

Randolph 0.00 0.00 0.00 0.00 0.00

Screven 0.63 0.37 0.91 7.82 9.73

Seminole 0.65 0.40 0.00 62.67 63.72

Sumter 0.00 0.00 0.00 0.00 0.00

Tattnall 1.18 0.97 1.17 3.37 6.69

Telfair 1.88 0.19 0.10 2.66 4.83

Terrell 0.00 0.00 0.00 0.00 0.00

Thomas 7.13 0.81 0.38 8.88 17.20

Tift 6.58 0.78 0.13 9.50 16.99

Toombs 2.66 0.42 0.00 3.89 6.97
Table 1. Water withdrawals from the Floridan aquifer system by county, 2000.--Continued

[Compiled by the U.S. Geological Survey, Tallahassee. General county locations are shown on figure 9. No water was reported 

withdrawn from the Floridan aquifer system in Mississippi during 2000]

1

Industrial includes commercial, mining, and power generation.

2

Irrigation includes agricultural irrigation and non-irrigation (livestock) and golf course irrigation.

12 Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000

Water withdrawals, in million gallons per day

State and County

 Public 

 supply

Domestric selfsupplied Industrial1 Irrigation2 Totals

Georgia

Treutlen 0.45 0.29 0.00 0.51 1.25

Turner 0.71 0.24 0.00 6.03 6.98

Twiggs 0.00 0.00 0.00 0.00 0.00

Ware 3.85 0.41 1.61 2.98 8.85

Washington 0.47 0.25 0.00 1.74 2.46

Wayne 1.91 1.09 59.52 1.46 63.98

Wheeler 0.27 0.30 0.00 0.69 1.26

Wilcox 0.62 0.33 0.00 17.20 18.15

Worth 1.46 0.92 0.00 25.37 27.75

South Carolina

Allendale 1.20 0.27 2.50 5.62 9.59

Bamberg 0.00 0.00 0.00 0.00 0.00

Barnwell 0.00 0.00 0.00 0.00 0.00

Beaufort 11.79 0.52 0.89 11.40 24.60

Berkley 0.00 0.00 0.00 0.20 0.20

Calhoun 0.00 0.00 0.00 0.00 0.00

Charleston 6.13 2.56 0.27 2.20 11.16

Clarendon 0.00 0.00 0.00 0.00 0.00

Colleton 2.35 1.30 0.13 0.72 4.50

Dorchester 0.00 0.00 0.00 0.00 0.00

Georgetown 0.00 0.00 0.00 0.00 0.00

Hampton 1.80 0.47 0.69 5.67 8.63

Jasper 1.26 0.18 0.15 2.87 4.46

Orangeburg 0.00 0.00 0.00 0.00 0.00

Williamsburg 0.00 0.00 0.00 0.00 0.00

TOTALS 1,329.00 165.53 576.28 1,948.73 4,019.54
Figure 9. Extent of the Floridan aquifer system in the southeastern United States by county.

Gulf of Mexico

Atlantic Ocean

Lake

Okeechobee

Extent of the

Floridan aquifer

system

GEORGIA

SOUTH CAROLINA

MISSISSIPPI ALABAMA

FLORIDA

0 100 200 MILES

0 100 200 KILOMETERS Hillsborough

Pasco

Osceola

Highlands

Polk

Manatee

De Soto

Duval

Miami-Dade

Broward

M o n r o e Monroe

Collier

Sarasota

Charlotte

Lee Hendry

Palm Beach

Glades

Martin

St.

Lucie

Okeechobee

Orange

Brevard

Indian

River

Lake

Hernando

Citrus

Sumter

Volusia

Seminole

Marion

Levy

Dixie Alachua Putnam Flagler Clay

St. Johns

Nassau

Baker Columbia

Union

Bradfor

Laf

d

ayette

Dixie

Madison

Hamilton

Suw

Jef

annee

ferson

Leon

Wakulla

Gadsden

Jackson

Calhoun

Liberty

Gulf Franklin

Bay Washington

Holmes

Walton Okaloosa

Santa

Rosa Escambia

Gilchrist

Camden

Charlton

Ware Brantley

Clinch

Echols

Lowndes

Lanier

Atkinson Pierce

Wayne McIntosh

Glynn

Coffee Bacon

Cook

Irwin

Long

Liberty

Bryan

Chatham

Effingham

Jeff Appling Davis

Irwin

Ben Hill

Grady

Thomas

Brooks

Decatur

Seminole

Miller Mitchell

Baker

Colquitt

Tift Worth Dougherty

Early

Clay Calhoun

Randolph

Terrell

Hardee

Wilcox

Turner

Crisp

Dooly

Pulaski

Dodge

Telfair

Wheeler

ToombsTattnall

C

Mont

andler - gomery

Laurens

Treutlen

Emanuel

Johnson

Bleckley

Houston

Sumter

Lee

Macon

Twiggs

Wilkinson Washington

Jefferson

Burke

JenkinsScreven

Bulloch

Baldwin

Mobile

Washington

Clarke

Escambia

Monroe

Conecuh

Covington

Geneva Houston

Jasper

Beaufort

Colleton

Charleston

Hampton

Allendale

Bamberg Barnwell

Orangeburg Dorchester

Berkeley

Clarendon

Williamsburg

Georgetown

Jackson

GeorgeGreene

Harrison

StonePerry

Wayne

Choctaw

Evans

Pinellas

Calhoun

General location of

the Floridan aquifer

system in the

southeastern United States

Water Withdrawals, 2000 13
Water Withdrawal Trends, 1950-2000

Figure 10. Total water withdrawals from the Floridan aquifer system, 1950-2000. (1950-1980 data from Bush and 

Johnston, 1988; 1985 data from Carr and others, 1990; 1990-1995 data from U.S. Geological Survey unpublished wateruse data.)

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

4,500

4,000

3,500

3,000

2,500

2,000

1,500

1,000

500

0

WATER WITHDRAWALS,

IN MILLION GALLONS PER 

DAY

YEAR

Withdrawals of water from the Floridan aquifer 

system have increased by more than 500 percent from 

630 Mgal/d in 1950 (Bush and Johnston, 1988) to 

4,020 Mgal/d in 2000 (fig. 10). The increase in withdrawals is attributed to increases in population, tourism, 

and agriculture production throughout the southeastern 

United States. Between 1950 and 2000, the combined 

populations of Alabama, Florida, Georgia, and South 

Carolina increased by more than 19 million people or 

169 percent (Hobbs and Stoops, 2002). A slight decrease 

in withdrawals from 1990-1995 is attributed to aboveaverage rainfall across the Southeast in 1995, which 

resulted in lower water demands for all irrigation purposes (agriculture crops, golf courses, and residential 

lawns).

Withdrawals from the Floridan aquifer system 

increased from 1950 to 2000 in each of the major 

withdrawal categories (public supply, irrigation, and 

industrial) (fig. 11). Public-supply withdrawals increased 

from 85 Mgal/d in 1950 (Bush and Johnston, 1988) to 

1,329 Mgal/d in 2000; nearly 60 percent of the increase 

occurred during the 20-year period between 1980-2000 

(table 2). Population served by public supply increased 

from 4.5 million in 1980 to 8.2 million in 2000. Domestic self-supplied withdrawals increased from 45 Mgal/d 

in 1950 (Bush and Johnston, 1988) to 166 Mgal/d in 

2000 (table 2).

Irrigation withdrawals increased from 90 Mgal/d 

in 1950 (Bush and Johnston, 1988) to 1,949 Mgal/d in 

2000 (table 2, fig. 11). Between 1960 and 2000, irrigated 

agricultural acreage in Alabama, Florida, Georgia, and 

South Carolina increased by more than 3 million acres 

(MacKichan and Kammerer, 1961; Hutson and others, 

2004). More than 60 percent of this increase occurred 

during the 20-year period between 1970-1990, when 

irrigation systems were introduced into north Florida and 

southwest Georgia (Pierce and others, 1984; Solley and 

others, 1998). Irrigation withdrawals decreased slightly 

14  Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000
Figure 11. Water withdrawals from the Floridan aquifer 

system by category, 1950-2000. (Bush and Johnston, 1988; 

Carr and others, 1990; U.S. Geological Survey unpublished 

water-use data.) 

Category 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

Public supply 85 150 270 325 430 500 616 822 993 1,088 1,329

Domestic self-supplied 45 30 80 87 138 158 209 120 181 209 166

Industrial1 410 570 745 870 852 1,103 855 820 828 584 576

Irrigation2 90 170 180 670 801 761 1,310 1,422 1,428 1,345 1,949

											Totals 	 630 	 920 	1,275 	1,952 	2,221 	2,522 	2,990 	3,184 	3,430 	3,226 	4,020

1

Includes commercial, mining, and power generation.

2

Includes agricultural irrigation, livestock, and golf course irrigation.

Table 2. Water withdrawals from the Floridan aquifer system by category, 1950-2000.

[Withdrawals in million gallons per day. Sources: 1950-1980 data from Bush and Johnston, 1988; 1985 data from Carr and others, 1990; 

1990-1995 data from U.S. Geological Survey unpublished water-use data]

2000

2,500

2,000

1,500

1,000

500

0

Public supply

Irrigation2

Industrial1

1950 1960 1970 1980 1990

WATER WITHDRAWALS,

IN MILLION GALLONS PER 

DAY

1

2

Includes commercial, mining, and power generation.

Includes agricultural irrigation, livestock, and

golf course irrigation.

YEAR

Center pivot used to irrigate peanuts in southwest Georgia. 

James Hook, University of Georgia, NESPAL

from 1990-1995 due to above-average rainfall during 

1995, and increased from 1995-2000 because of belowaverage rainfall across the Southeast during that period.

Industrial water withdrawals increased from 

410 Mgal/d in 1950 (Bush and Johnston, 1988) to 

1,103 Mgal/d in 1975, but decreased to 576 Mgal/d in 

2000 (table 2, fig. 11). Lower industrial withdrawals 

after the mid-1970s are a result of improved efficiencies, increased water recycling and conservation measures, and changes in regulations designed to reduce the 

discharge of pollutants (Solley and others, 1998). A large 

portion of the recent decrease between 1990 and 2000 is 

a result of several large self-supplied industrial facilities 

closing in Florida and Georgia.

Water Withdrawal Trends, 1950-2000 15

Ground water from the Floridan aquifer system is the 

primary source of irrigation water in central and north 

Florida and south Georgia.
Water Quantity and Quality Concerns

Figure 12. Fluctuations of ground-water levels in selected wells in 

the Upper Floridan aquifer. (Marella and Sepúlveda, 2004; Michael 

Peck, U.S. Geological Survey, written commun., April 2004.)

YEAR

1950 60 70 80 90 2000

-140

-120

-100

-80

-60

-40

LAYNE-ATLANTIC 36Q008

(near Savannah, GA)

WATER LEVEL, IN FEET ABOVE

OR BELO

W THE NGVD OF 1929

-40

-20

0

20

40

60

80

100

OKALOOSA 29 (near Pensacola, FL)

NGVD of 1929

Land surface datum,

178 feet above

Depth 710 feet

Casing 524 feet

Land surface datum,

9.2 feet above NGVD of 1929

Depth 406 feet Casing 250 feet

Sinkholes provide a direct pathway for contaminants 

to enter the aquifer.

Harley Means, Florida Geological Survey

The cumulative effects of large quantities of groundwater withdrawals from the Floridan aquifer system have 

caused extensive water-level drawdowns and saltwater 

intrusion in many areas. In northeastern Florida and 

eastern Georgia (near Savannah, Georgia), water levels 

have declined since 1950 at an average rate of about onethird to one-half foot per year (Barlow, 2003) (fig. 12). 

Along coastal areas of the western panhandle of Florida 

(near Pensacola, Florida), water levels have declined 

about 100 feet since 1950 (fig. 12); consequently, well 

fields have been relocated farther inland or have been 

supplemented with surface water (Purdum and Penson, 

1998). Effects of increased water withdrawals also are 

evident at many lakes, wetlands, and springs, as lake 

levels have declined and wetlands have dried up in many 

areas throughout Florida (Kautz and others, 1998) and 

discharge at some springs has decreased or ceased over 

time (Spechler and Schiffer, 1995).

 Along the coasts of Georgia and South Carolina, 

high chloride concentrations in ground water in the aquifer system are attributed to intrusion of seawater caused 

by large ground-water withdrawals in the Savannah, 

Georgia, and Hilton Head Island, South Carolina, areas 

(Barlow, 2003). Other areas that have limited withdrawals because of elevated chloride concentrations or the 

potential for saltwater intrusion include the central east 

and west coasts of Florida (Berndt and others, 1998b; 

Barlow, 2003) and along the coast of Georgia (Krause 

and Clarke, 2001).

16 Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000

Empty pesticide cans litter a sinkhole in central Florida. 
Mathew O’Malley, St. Johns River Water Management District

untreated stormwater and urban runoff to directly enter 

the Upper Floridan aquifer (Sepúlveda, 2002). As a 

result, several water-supply systems in this area can 

no longer depend entirely on the Upper Floridan aquifer for drinking water, and now must also rely on the 

deeper Lower Floridan aquifer. About 40 percent of the 

water withdrawn in Orange County for public supply 

was obtained from the Lower Floridan aquifer in 2000 

(McGurk and Presley, 2002).

Water Quantity and Quality Concerns 17

Increased water withdrawals from the Floridan aquifer system have resulted in lower lake levels throughout central, 

north, and southwest Florida.

Land-use practices affect the water quality of the 

Floridan aquifer system. The aquifer system is unconfined in many areas and sinkholes and sinking streams 

commonly provide a direct pathway for land-surface 

contaminants to enter the ground-water system. Nitrate, 

herbicides, and pesticides from agricultural activities 

have been detected in many of the springs and wells in 

northern Florida. For example, nitrate concentrations 

in Manatee Springs (near Gainesville, Florida) have 

increased from 0.4 milligrams per liter in 1946 to more 

than 1.5 milligrams per liter in the late 1990s (Katz and 

others, 1999). Herbicides also have been detected in 

trace concentrations in 9 of 15 springs discharging from 

the Upper Floridan aquifer in south Georgia (Hippe, 

1997). In addition, household trash and other waste 

products have been dumped in sinkholes throughout the 

years, thus providing a direct source of contamination to 

the aquifer.

Urban runoff and septic tank effluent can affect 

the quality of water in populated areas by contributing 

nitrate and organic compounds (Bradner, 1991; Berndt 

and others, 1998a; Christy Crandall, U.S. Geological 

Survey, written commun., 2004). In the Orlando area 

(Orange County, Florida), 240 drainage wells allow 

Aerial photograph of a large sinkhole that formed in Winter 

Park, Florida, May 1981. Sinkholes are a common feature of the 

Floridan aquifer system in central and north Florida.

Tom Scott, Florida Geological Survey

Lowered lake levels in northern Florida are evident by docks and bridges that rise from dried lake bottoms. 
Large housing developments, like this one in southwest Florida, have resulted in a large increase in public-supply water 

demands over the past 30 years. 

Harley Means, Florida Geological Survey

18 Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000

Most urban areas throughout central, north, and southwest Florida depend on water from the Floridan aquifer systems 

as their primary souce of water.
References

Aucott, W.R., Davis, M.E., and Speiran, G.K., 1986, 

Geohydrologic framework for the Coastal Plain aquifers of South Carolina: U.S. Geological Survey WaterResources Investigations Report 85-4271, 7 sheets.

Barlow, P.M., 2003, Ground water in freshwater-saltwater environments of the Atlantic Coast: U.S. 

Geological Survey Circular 1262, 113 p.

Berndt, M.P., Galeone, D.R., Spruill, T.B., and Crandall, 

C.A., 1998a, Ground-water quality in three urban 

areas in the Coastal Plain of the southeastern United 

States, 1995: U.S. Geological Survey Water-Resources 

Investigations Report 97-4234, 25 p. 

Berndt, M.P., Oaksford, E.T., and Mahon G.L., 1998b, 

Groundwater, in Fernald, E.A., and Purdum, E.D., 

Water resources atlas of Florida: Florida State University, Institute of Science and Public Affairs, p. 38-63.

Bradner, L.A., 1991, Water quality in the upper Floridan aquifer in the vicinity of drainage wells, Orlando, 

Florida: U.S. Geological Survey Water-Resources 

Investigations Report 90-4175, 57 p. 

Bush, P.W., and Johnston, R.H., 1988, Ground-water 

hydraulics, regional flow, and ground-water development of the Floridan aquifer system in Florida and 

parts of Georgia, South Carolina, and Alabama: U.S. 

Geological Survey Professional Paper 1403-C, 80 p.

Carr, J.E., Chase, E.B., Paulson, R.W., and Moody, 

D.W., 1990, National water summary 1987—Hydrologic events and water supply and use: U.S. Geological Survey Water-Supply Paper 2350, 553 p.

Fanning, J.L., 2003, Water use in Georgia by county for 

2000 and water-use trends for 1980-2000: Atlanta, 

Georgia Department of Natural Resources, Environmental Protection Division, Georgia Geologic Survey 

Information Circular 106, 176 p.

Gilliom, R.J., Hamilton, P.A., and Miller, T.L., 2001, 

The National Water-Quality Assessment Program—

Entering a new decade of investigations: U.S. Geological Survey Fact Sheet 071-01, 4 p.

Hobbs, Frank, and Stoops, Nicole, 2002, Demographic 

trends in the 20th century: Washington D.C., U.S. 

Department of Commerce, Census Bureau, Census 

2000 Special Reports, Series CENSR-4, 143 p. 

Hippe, D.J., 1997, Pesticide occurrence in the Upper 

Floridan aquifer in the Dougherty Plain and Marianna 

Lowlands districts, southwest Georgia and adjacent 

areas of Alabama and Florida, in Hatcher, K.J. ed., 

Proceedings of the 1997 Georgia Water Resource 

Conference, University of Georgia, Athens, Georgia, 

p. 65-67.

Hutson, S.S., Barber, N.L., Kenny, J.F., Linsey, K.S., 

Lumia, D.S., and Maupin, M.A., 2004, Estimated use 

of water in the United States in 2000: U.S. Geological 

Survey Circular 1268, 46 p.

Katz, B.G., Hornsby, H.D., Bohlke, J.F., and Mokray, 

M.F., 1999, Sources and chronology of nitrate contamination in spring waters, Suwannee River Basin, 

Florida: U.S. Geological Survey Water-Resources 

Investigations Report 99-4252, 54 p.

Kautz, R.S., Haddad, Kenneth, Hoehn, T.S., Rogers, 

Thomas, Estevez, E.D., and Atkeson, Tom, 1998, 

Natural systems, in Fernald, E.A., and Purdum, E.D., 

Water resources atlas of Florida: Florida State University, Institute of Science and Public Affairs, p. 82-113.

Krause, R.E., and Clarke, J.S., 2001, Coastal ground 

water at risk—Saltwater contamination at Brunswick, 

Georgia and Hilton Head Island, South Carolina: U.S. 

Geological Survey Water-Resources Investigations 

Report 01-4107, poster.

References 19
MacKichan, K.A., and Kammerer, J.C., 1961, Estimated 

use of water in the United States, 1960: U.S. Geological Survey Circular 456, 44 p.

Marella, R.L., 2004, Water withdrawals, use, discharge, 

and trends in Florida, 2000, U.S. Geological Survey 

Scientific Investigations Report 2004-5151, 138 p.

Marella, R.L., and Sepúlveda, A.A., 2004, Potentiometric surface of the Upper Floridan aquifer in 

Florida, May 2000: Florida Geological Survey Map 

Series 149, 1 sheet.

Maupin, M.A., and Barber, N.L., 2005, Estimatd withdrawals from principal aquifers in the United States, 

2000: U.S. Geological Survey Circular 1279, 46 p.

McGurk, Brian, and Presley, P.F., 2002, Simulation of 

the effects of groundwater withdrawals on the Floridan 

aquifer system in east-central Florida (Model expansion and revision): Palatka, St. Johns River Water 

Management District, Technical Publication SJ2002-3, 

151 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.

Miller, J.A., 1990, Ground water atlas of the United 

States, Segment 6, Alabama, Florida, Georgia, and 

South Carolina: U.S. Geological Survey Hydrologic 

Investigation Atlas 730-G, 28 p.

Peck, M.F., McFadden, K.W., and Leeth, D.C., 2005, 

Effects of decreased ground-water withdrawals on 

ground-water levels and chloride concentrations in 

Camden County, Georgia, and ground-water levels in 

Nassau County, Florida, from September 2001 to 

May 2003: U.S. Geological Survey Scientific Investigations Report 2004-5295, 36 p.

Pierce, R.R., Barber, N.L., and Stiles, H.R., 1984, 

Georgia irrigation, 1970-80, a decade of growth: U.S. 

Geological Survey Water-Resources Investigations 

Report 83-4177, 29 p.

Purdum, E.D., and Penson, Georgann, 1998, Northwest 

Florida Water Management District, in Fernald, E.A., 

and Purdum, E.D., Water resources atlas of Florida: 

Florida State University, Institute of Science and 

Public Affairs, p. 170-193.

Reese, R.S., 2002, Inventory and review of aquifer 

storage and recovery in southern Florida: U.S. 

Geological Survey Water Resources Investigations 

Report 02-4036, 56 p.

Renken, R.A., 1998, Ground water atlas of the United 

States, Segment 5, Arkansas, Louisiana, Mississippi: 

U.S. Geological Survey Hydrologic Investigation 

Atlas 730-F, 28 p.

St. Johns River Water Management District, 2004, Water 

use in the St. Johns River Water Management District, 

2000: Palatka, Technical Fact Sheet SJ2004-FS1, 6 p.

Sepúlveda, Nicasio, 2002, Simulation of ground-water 

flow in the intermediate and Floridan aquifer systems 

in peninsular Florida: U.S. Geological Survey WaterResources Investigations Report 02-4009, 130 p.

Scott, T.M., Means, G.H., Meegan R.P., Upchurch, S.B., 

Copeland, R.E., Jones, James, Roberts, Tina, and Willet, Alan, 2004, Springs of Florida: Florida Geological 

Survey Bulletin Number 66, 377 p. 

Solley, W.B., Pierce, R.R., and Perlman, H.A., 1998, 

Estimated use of water in the United States in 1995: 

U.S. Geological Survey Circular 1200, 71 p.

Southwest Florida Water Management District, 2002, 

Estimated water use in the Southwest Florida Water 

Management District, 2000: Brooksville, Resource 

Conservation and Development Department, Conservation Projects Section, 151 p.

Spechler, R.M., and Schiffer, D.M., 1995, Springs of 

Florida: U.S. Geological Survey Fact Sheet 

FS-151-95, 2 p.

U.S. Geological Survey, 2003, Principal aquifers of the 

United States, The National atlas of the United States: 

U.S. Geological Survey, scale 1:5,000,000, 1 sheet.

University of Nebraska, 2004, National drought summaries January 4-December 26, 2000: accessed 

February 19, 2004, http://www.drought.unl.edu/dm/

archive/2000.

20 Water Withdrawals and Trends from the Floridan Aquifer System in the Southeastern United States, 1950-2000