U.S. Department of the Interior

U.S. Geological Survey

USGS Fact Sheet 011-99

April 1999

Georgia

The U.S. Geological Survey (USGS),

the Nation’s largest natural sciences

and civilian mapping agency, provides reliable and impartial scientific

information to resource managers,

planners, and others throughout the

Nation. This information contributes

to sound conservation and management of natural resources; enhances

the quality of life by monitoring

water, biological, energy, and mineral

resources; and minimizes losses from

numerous natural hazards.

USGS activities in Georgia are conducted in cooperation with numerous

local, State, and Federal agencies.

Cooperating agencies include the City

of Brunswick; Albany Water, Gas,

and Light Commission; City of Lawrenceville; Georgia Department of

Natural Resources; U.S. Army Corps

of Engineers; U.S. Environmental

Protection Agency; and National

Park Service.

Earth Resources

Georgia has a rich endowment of

natural resources. The average annual

precipitation of 50 inches results in a

generally abundant supply of freshwater that includes numerous productive aquifers (fig. 1) and an extensive

system of rivers (fig. 2). The USGS

has been collecting water-resources

data in Georgia since the 1890’s. The

USGS currently collects data at

approximately 120 continuous-record

and 77 partial-record streamflowgaging stations, 18 reservoir stage

and contents gaging stations, and 180

continuous-record monitoring wells.

These data are used by waterresources managers to make decisions

concerning water supplies, flood

control, hydroelectric power, irrigation, bridge design, wildlife management, and pollution abatement.

Water Use and Competition

Water-resources management requires information about water use.

During 1995, Georgia water consumption, excluding use for thermoelectric power generation, was

about 2,740 million gallons per day

(Mgal/d) (fig. 3), an increase of about

450 Mgal/d (16 percent) from 1990.

Total water use in Georgia during

1995 was about 5,800 Mgal/d.

Ground water accounted for about 20

percent of total withdrawals, 99

percent of which was used for

irrigation, industry and mining, public

supply, and domestic and commercial

purposes. Surface water accounted

for about 80 percent of total withdrawals, almost 70 percent of which

was used for thermoelectric power

generation, and most of the remainder

was used for public supply, industry

and mining, and irrigation.

Historically, an adequate water

supply has met the needs of users in

Georgia. However, population

growth, economic development, and

recent droughts have increased

demand, decreased supplies, and

created competition among water

users. Georgia is a “headwaters”

State, and the effects of increased

water development and drought on

rivers that originate in Georgia spread

downstream (southwestward) into

Alabama in the Alabama-CoosaChattahoochee R

Withlacoochee R

Altamaha R

Satilla R

Ocmulgee R

Oconee R

Suwannee

Alapaha R

F lint R

Savannah R

Ogeechee R

Coosa

Eto wah

Oostanaula

Chattahoochee R

Withlacoochee R

Altamaha R

Satilla R

Ocmulgee R

Oconee R

Suwannee

Alapaha R

F lint R

Savannah R

Ogeechee R

Coosa

Eto wah

Oostanaula

9

7

5

3

1

Average annual 

 discharge, in million 

 gallons per minute

ALABAMA

FLORIDA

Figure 2. Average annual discharge of

major streams in Georgia.

Figure 1. Principal aquifers, areas of use; and physiographic provinces.

COASTAL PLAIN AQUIFERS

 Surficial aquifer system (not a principal aquifer)

 Floridan aquifer system 

 Claiborne, Clayton, and Providence aquifers

 Cretaceous aquifer systems

PIEDMONT AND BLUE RIDGE AQUIFERS

 Crystalline-rock aquifers

VALLEY AND RIDGE AND APPALACHIAN

 PLATEAUS AQUIFERS

 Paleozoic-rock aquifer

BLUE RIDGE

VALLEY AND RIDGE AND APPALACHIAN PLATEAUS

PIEDMONT

COASTAL PLAIN
science for a changing world

Tallapoosa (ACT) River Basin and

southward into Florida in the Apalachicola-Chattahoochee-Flint (ACF)

River Basin. As part of a multi-State

and multi-Federal agency Comprehensive Study of the ACT and ACF

basins, the USGS investigated water

availability and the hydrologic effects

of increased water-resource development to support development of a

water-allocation formula that is

planned to distribute water resources

equitably to meet the needs of society

and the environment.

Piedmont Hydrogeology

USGS scientists are using surface

geologic mapping and borehole

geophysical methods to evaluate

ground-water availability by characterizing complex, fractured crystalline-rock aquifers near Lawrenceville.

Because of rapid population growth

and water-supply needs, many

communities in the Metropolitan

Atlanta area are exploring ground

water as a supplement to surfacewater supplies. Because of the

complexity of metamorphic and

igneous rocks and their secondary

fractures, well yields can differ tremendously over short distances.

Conceptual models of these aquifers

often are inaccurate. USGS personnel

are mapping these rocks and fractures

in three dimensions and refining the

conceptual models of these complex

aquifers. Results from this investigation will assist water-management

agencies in developing and protecting Piedmont ground-water resources

in Georgia.

Coastal Ground Water and

Saltwater Intrusion

Ground-water pumping in coastal

southeastern Georgia and adjacent

parts of South Carolina and Florida

has degraded the quality of water

locally in the Upper Floridan aquifer.

The pumping has resulted in substantial ground-water-level decline and

upward migration of saltwater in the

Brunswick area and in encroachment

of seawater into the aquifer at the

northern end of Hilton Head Island,

South Carolina, about 30 miles

northeast of Savannah. The USGS, in

cooperation with the Georgia Department of Natural Resources (DNR), is

conducting a hydrologic investigation

of the coastal area to determine the

paths and rates of saltwater movement into the aquifer; determine other

areas where saltwater contamination

could occur; assess alternative

sources of freshwater supplies; and

develop a monitoring-well network to

assess ground-water levels and

quality. In cooperation with the City

of Brunswick and Glynn County, the

USGS also is investigating possible

mechanisms and movement of

saltwater contamination in the

Brunswick area and the susceptibility

of other areas to upward migration of

saltwater, and monitoring and evaluating changes in ground-water levels

and quality.

Mineral Resource Investigations

Geologic, geophysical, geochemical,

minerals information, and related

geoscience data are being compiled

by USGS scientists to help evaluate

the mineral resources of the Southeastern United States. Potential

environmental effects of mineralresource development also are being

evaluated. USGS partnerships with

State Geological Surveys, universities, and other cooperators have

resulted in completion of a new

geochemical database for Georgia,

compilation of digital geologic and

lithologic maps, and evaluation of

and significant revisions to mineral

deposits records.

The USGS collects, analyzes, and

disseminates information about the

supply and demand for minerals. In

1997, Georgia produced $1.68 billion

in nonfuel raw minerals (mainly

kaolin and crushed stone). Georgia is

the leading clay-producing State,

accounting for about one-fourth of

the national total. In 1997, Georgia

led the Nation in the production of

kaolin and fuller’s earth, was second

in barite and crude mica, third in ironoxide pigments, fourth in common

clays, fifth in dimension stone and

feldspar, and seventh in crushed

stone. USGS mineral production

information is available on the World

Wide Web (WWW) at http://minerals.er.usgs.gov/minerals, on Mines

Faxback at (703) 648-4999, and is

published three times annually on

CD-ROM.

Environment

Georgia’s environment is constantly

changing as natural processes and

human actions affect it. The USGS

plays an important role in integrating

the physical and biological sciences

to provide critical scientific information to help society make informed

environmental decisions.

Pesticides from Suburban, Urban,

and Agricultural Sources

In Georgia, a wide range of pesticides

is applied to suburban and urban

areas, forests, crops, and pastures.

Leaching or runoff of even small

amounts of pesticides in these areas

could harm aquatic life or contaminate drinking-water supplies. The

potential for pesticide contamination

goes beyond agricultural areas that

Total water use, in

 million gallons per day

Less than 1

1 to 5

5 to 10

10 to 20

20 to 1,010

ALABAMA

CAROLINA

SOUTH 

FLORIDA

Lawrenceville

Atlanta

Brunswick

Savannah

Figure 3. Water use in Georgia, by

county, 1995.
Georgia

typically are emphasized in most

environmental monitoring programs

and evaluation of best management

practices for pest control. In Georgia,

pesticides are most prevalent in

streams draining suburban and urban

areas. Although pesticide concentrations generally are below existing

U.S. Environmental Protection

Agency (EPA) standards for drinking

water, concentrations of selected

pesticides used to control insects

often exceed guidelines for protection

of aquatic life in streams draining

suburban and urban areas. The

continued urbanization of forest and

pasture land, surrounding Metropolitan Atlanta in particular, is likely to

be accompanied by increasing

numbers and concentrations of

pesticides in streamwater, the area’s

primary source of drinking water.

Intensive analysis of streamflow and

pesticide-concentration data from

selected sites has shown that stormwater runoff carries much of the total

quantity of pesticides transported by

streams. The quantities of pesticides

transported by streams, however,

often represent less than 1 percent of

annual pesticide use within the

associated watersheds.

Drinking Water Initiative

USGS research, in collaboration with

the Centers for Disease Control and

Prevention and the EPA, is focusing

on the protozoan Cryptosporidium, a

parasite of major concern to water

utility companies and regulatory

agencies. Cryptosporidium is known

to cause illness and death. A major

goal of the USGS study is to develop

and field test sample-collection and

processing techniques that will

improve the recovery and precision of

analyses for Cryptosporidium. Work

to date has concentrated on developing appropriate methods for publicsupply water. Future work will

concentrate on methods appropriate

for raw water, using the Chattahoochee River in the Metropolitan

Atlanta area as a field testing site.

Dredge Spoil Runoff and Habitat Quality,

Lower Savannah River

USGS scientists are investigating the

effects of upland disposal of materials

dredged from Savannah Harbor on

the wildlife in disposal areas and in

the Savannah River downstream from

disposal areas. Contaminants from

municipal and industrial activities

along the lower Savannah River

concentrate in harbor sediment,

which is periodically dredged during

channel maintenance. The USGS is

testing the toxicity of sediments and

water from areas downstream from

dredge spoils, and is analyzing tissue

residues in birds and raccoons

collected from the disposal areas.

Testing revealed an accumulation of

trace elements such as mercury and

selenium in freshwater worms

exposed to sediments and in the livers

of wildlife from the spoil areas.

Results from this USGS study

indicate that dredge spoil runoff may

be adversely affecting wildlife habitat

along the lower Savannah River.

Striped Bass Evaluation, Savannah River

Estuary

The installation of a tide gate in 1975

to enhance navigability in the Savannah River Estuary created salinity

levels on striped bass spawning

grounds that were toxic to eggs and

larvae. Reproductive failure followed,

and the bass population declined

throughout the 1980’s, leading to

closure of the recreational fishery. In

1991, the tide gate was removed, and

other modifications were made to

prevent the transport of bass eggs and

larvae from suitable spawning

grounds to high-salinity areas downstream. Also in 1991, the Georgia

DNR began an intensive restocking

program of striped bass fingerlings,

expecting that restocked females

would mature and begin spawning by

1995. USGS scientists monitor the

number and distribution of striped

bass eggs and salinity throughout the

estuary. Salinity currently seems

suitable on spawning grounds;

however, egg numbers have not

changed significantly and are still

critically low. USGS biologists are

investigating whether the maturational status of restocked females, or

hydrologic and salinity factors are

responsible for unsuccessful reproduction in the striped bass population.

Natural Hazards

Natural hazards cause financial losses

that average $52 billion per year in

the United States. In Georgia, the

USGS provides information on

selected natural hazards including

floods, droughts, coastal storm

surges and hurricanes, sinkholes,

and earthquakes.

Floods and Droughts

The USGS has documented floods

and droughts in Georgia since the

1890’s using data from its statewide

streamflow-gaging network. About 60

USGS continuous-record streamflowgaging stations are equipped with

data transmitters that provide near

realtime streamflow information that

can be accessed from the USGS

Georgia WWW site at http://georgia.

usgs.gov. Since 1900, several major

floods have occurred in Georgia. In

July 1994, parts of central and

southwestern Georgia in the Flint and

Ocmulgee River Basins were inundated by record flooding from Tropical Storm Alberto, causing 33 deaths

and property damage estimated at $1

billion. USGS personnel work

throughout the duration of a flood to

maintain streamflow-gaging stations,

measure peak flows and floodelevation profiles, and provide critical

information to emergency management personnel and the public.

The effects of droughts are not as

immediate as those of floods.

Droughts are sustained for several

months, encompass large areas, and

affect agriculture, recreation, navigation, power production, and municipal activities. Since 1900, several
USGS State Representative

3039 Amwiler Road

Suite 130

Atlanta, GA 30360-2824

(770) 903-9100

FAX (770) 903-9199

USGS office locations

USGS Home Page:

http://www.usgs.gov

Reports and products:

1-888-ASK-USGS

Printed on recycled paper

major droughts have occurred in

Georgia. The drought of 1985–86 was

one the most severe of the century;

streamflow throughout the State was

at or near the lowest on record. USGS

personnel monitor surface- and

ground-water conditions throughout

droughts and provide important

information to water-management

agencies and the public.

Geologic Hazards

Earthquakes and ground failures are

uncommon in Georgia; however,

these events can pose threats to

human life and property. Although

only small to moderate earthquakes

have occurred in Georgia in recorded

history, large seismic events that

occurred in nearby States during the

1800’s affected Georgia. The USGS

National Earthquake Information

Center web site (http://wwwneic.

cr.usgs.gov) documents earthquake

activity using the U.S. National

Seismograph Network. Ground

failures, such as landslides, are a

common secondary effect of seismic

shaking, and can be caused by

unstable surface conditions. The

USGS supports studies to identify

areas of potential ground failure to

ensure stability of large structures

such as dams.

Information and Mapping

USGS information and products are

disseminated in a wide variety of

formats, including numerous databases, WWW sites, and scientific

reports and maps. Among the most

popular USGS products are the

1:24,000-scale topographic maps that

show natural and cultural landscape

features, with contour lines that show

elevation and the configuration of the

terrain. Georgia is covered by 1,017

topographic maps at this scale. These

maps are used for many purposes,

including natural-resource monitoring, civil engineering, and recreation.

The USGS WWW site for Georgia

http://georgia.usgs.gov contains

additional information about USGS

programs in Georgia, describes

hydrologic conditions, describes the

availability of various information

products, and provides links to other

USGS sites. Additional information

about USGS hydrologic, geologic,

biologic, and mapping programs

throughout the Nation as well as

instructions for obtaining USGS

reports and maps is available on the

USGS Home Page at http://www.

usgs.gov.

Cooperative Mapping Program

The USGS and University of Georgia

have entered into an Innovative

Partnership agreement to produce

statewide digital line graph coverages

for transportation and hydrography

data categories. This agreement

resulted from a requirements identification and review for these data

categories, conducted by the Georgia

Geographic Information Systems

Advisory Council. The Statewide

coverage originally collected by the

Georgia Department of Transportation was used as the basis for this

partnership. The 1:12,000-scale

digital orthophoto quadrangles

(1-meter resolution, digital blackand-white images produced from

National Aerial Photography Program

photos) are being used to revise the

existing State dataset to upgrade

standards and data structures for

National hydrologic datasets. Georgia

is one of the first States to adopt these

data standards.

Spatial Analysis Technologies

The USGS and Georgia Institute of

Technology established joint “Centers

for Spatial Analysis Technologies” in

1991. These Centers are co-located

on the Georgia Tech campus and

house interdisciplinary teams that

conduct geographic information

system (GIS) projects, research, and

education. The Centers apply GIS

technologies in support of projects

about natural hazards, environmentalquality indicators, infrastructure,

land-resources management, and

design and construction of geospatial

datasets. An important recent product

is the Digital Atlas of Georgia, which

consists of numerous digital thematic

datasets (land use, geology, hydrography, topography, highways, and

political boundaries), compiled onto a

CD-ROM. The product is designed

for use by environmental professionals, resource managers and

planners, educators and students,

and many others.

The USGS has 145

employees in Georgia

Atlanta

Athens

Albany

Norcross

Savannah

Tifton