U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2013–3073

March 2014

Prepared in cooperation with the Louisiana Department of Transportation and Development 

Water Resources of Jefferson Parish, Louisiana

47

39

90

90

10

510

610

Area enlarged

Mississippi

River Intracoastal Waterway

Big

Mar

Lake

 Lery

Lake

Cataouatche

Barataria

Bay 

Lake

Pontchartrain

Lake

Salvador

Little

 Lake

GULF OF MEXICO

Barataria

Bay 

Lake

Pontchartrain

Mississippi River Intracoastal Waterway

Big

Mar

Lake

 Lery

Lake

Cataouatche

Lake

Salvador

Little

 Lake

0 10 20 KILOMETERS

0 10 20 MILES

90°10' 90°00' 89°50'

30°00'

30°10'

29°50'

29°40'

29°30'

29°20'

29°10'

90°20'

Base modified from U.S. Geological Survey digital data

Albers Equal-Area Conic projection

North American Datum of 1983

TEXAS

ARKANSAS MISSISSIPPI

LOUISIANA

JEFFERSON

PARISH

C

07373290

ORLEANS

PARISH

PLAQUEMINES PARISH

JEFFERSON PARISH

LAFOURCHE

PARISH

ORLEANS

PARISH

PLAQUEMINES PARISH

JEFFERSON PARISH

LAFOURCHE

PARISH

ST. BERNARD

PARISH New Orleans New Orleans

Bridge

 City

Belle

 Chasse Availability of groundwater in Jefferson Parish—

 Modified from Prakken, 2009

 Approximate area of freshwater in the

 Gonzales-New Orleans aquifer

 Approximate area of freshwater in the

 Norco aquifer

Marsh and swamp

Line of section (fig. 3)

U.S. Geological Survey surface-water quality

 site and number

U.S. Geological Survey surface-water discharge

 site and number

Well location and name

EXPLANATION

Jf-178

07374525

07373290

A A'

O

C

Jf-178

Jf-186

Jf-156

07374525 O

A

A' 90

610

Mississippi RiverMississippi River

Lake

Pontchartrain

0 5 10 MILES

0 5 10 KILOMETERS

30°00'

29°55'

30°05'

90°10' 90°00' ORLEANS PARISH JEFFERSON PARISH

Jf-178

Jf-186

Jf-156

Bridge

 City

New Orleans

Metairie Kenner

A'

A

Introduction 

This fact sheet presents a brief overview of groundwater 

and surface-water resources in Jefferson Parish, Louisiana 

(fig. 1). Information on the availability, use, and quality of 

water from groundwater and surface-water sources in the parish 

is discussed. Previously published reports (see References 

Cited section) and data stored in the U.S. Geological Survey’s 

National Water Information System (http://waterdata.usgs.gov/

nwis) are the primary sources of this information. 

In 2010, about 817 million gallons per day (Mgal/d) of 

water were withdrawn in Jefferson Parish, approximately 

810 Mgal/d from surface-water sources and approximately 

7.16 Mgal/d from groundwater sources1 (table 1). Power 

generation accounted for about 91 percent of the total water 

withdrawn. Other water-use categories included public supply, 

industrial, rural domestic, livestock, and general irrigation (table 

2). Water-use data collected at 5-year intervals from 1960 to 

2010 (fig. 2) indicated that water withdrawals peaked at about 

1,600 Mgal/d during 1975 and 1980 in Jefferson Parish. The 

large increase in surface-water withdrawals from 1970 to 1975 is 

primarily attributable to withdrawals for power generation.

1

Tabulation of withdrawals in the text and tables may produce different totals 

because of rounding; nonrounded numbers are used for calculation of total 

withdrawals. 

Figure 1. Location of study area and distribution of fresh groundwater in Jefferson Parish, Louisiana. 
Table 1. Water withdrawals, in million gallons per day, by source 

in Jefferson Parish, Louisiana, 2010 (modified from Sargent, 2011).

Aquifer or 

surface-water body Groundwater Surface water

Mississippi River 

point-bar deposits

0.00

Shallow aquifers of the

New Orleans area

0.00

Gramercy aquifer 0.02

Norco aquifer 0.04

Gonzales-New Orleans aquifer 7.09

Mississippi River 809.56

Miscellaneous streams 0.04

Total 7.16 809.59

Table 2. Water withdrawals, in million gallons per day, by use 

category in Jefferson Parish, Louisiana, 2010 (modified from 

Sargent, 2011).

Use category Groundwater Surface water Total

Public supply 0.00 64.95 64.95

Industrial 2.24 4.19 6.43

Power generation 4.79 740.42 745.21

Rural domestic 0.04 0.00 0.04

Livestock 0.00 0.04 0.04

General irrigation 0.08 0.00 0.08

Total 7.16 809.59 816.75

Groundwater

Surface water

EXPLANATION

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Year

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

Annual withdrawal, in million gallons per day

Figure 2. Water withdrawals in Jefferson Parish, Louisiana, 

1960–2010 (Sargent, 2011).

Groundwater Resources 

The primary groundwater resources of Jefferson Parish include 

the Norco and Gonzales-New Orleans aquifers (fig. 3). Other aquifers 

underlying the area, including Mississippi River point bar deposits, the 

shallow aquifers of the New Orleans area, and the Gramercy aquifer, 

contain very hard2

 water that also has high iron concentrations (greater 

than 300 micrograms per liter [μg/L]) or only saltwater (water with 

chloride concentrations greater than 250 milligrams per liter [mg/L]). 

These aquifers generally are not utilized for water supply in Jefferson 

Parish and are not discussed further in this report (Prakken, 2009).

Recharge to aquifers in Jefferson Parish is typically by infiltration 

of precipitation in outcrop or subcrop areas, leakage from adjacent 

aquifers, and seasonal flow from rivers and canals. Discharge from 

aquifers is by natural flow into rivers or canals, leakage into adjacent 

aquifers, and withdrawals from wells. State well-registration records 

listed 108 active water wells in Jefferson Parish in 2009, including 50 

industrial, 34 irrigation, 10 domestic, 10 public supply, and 4 power 

generation (Louisiana Department of Natural Resources, 2009). 

Norco Aquifer

The Norco aquifer is present in most of northern Jefferson 

Parish, with the exception of a small area west of Metairie, 

but contains freshwater (water with a chloride concentration 

of 250 [mg/L] or less) only in a narrow strip along the Lake 

Pontchartrain shoreline (fig. 1). The Norco aquifer generally ranges 

from about 50 to 150 feet (ft) in thickness in northern Jefferson Parish 

and is composed of fine to coarse sand and, possibly, fine gravel 

present in thin layers a few feet thick in the lower part of the aquifer 

(Hosman, 1972; Dial and Kilburn, 1980). A clay layer generally 

separates the Norco aquifer from the underlying Gonzales-New 

Orleans aquifer. 

State well-registration data indicated that in 2009 there were 

20 active wells screened in the Norco aquifer in Jefferson Parish, 

including 10 irrigation, 6 industrial, 3 domestic, and 1 public supply. 

Depths of these wells ranged from 250 to 480 ft below land surface, 

with a median depth of 412.5 ft below land surface. The records 

indicated that yields from wells screened in the Norco

aquifer range from 3 to 2,500 gallons per minute (gal/min) (Louisiana 

Department of Natural Resources, 2009). In 2010, withdrawals

from the Norco aquifer in Jefferson Parish totaled about 0.04 Mgal/d 

(table 1). 

In northwestern Jefferson Parish, water levels in the 

Norco aquifer at well Jf-186 (fig. 1) have fluctuated from about 

0 to 9 ft below National Geodetic Vertical Datum of 1929 (NGVD 

29) since 1996 (fig. 4). Freshwater in the Norco aquifer at well 

Jf-186 is moderately hard (Dial and Tomaszewski, 1988). The iron 

concentration exceeds the U.S. Environmental Protection Agency’s 

Secondary Maximum Contaminant Level (SMCL)3 for drinking water 

of 300 μg/L and color exceeds the SMCL of 15 platinum cobalt units. 

Manganese concentrations are low (less than the SMCL of 50 μg/L). 

2

Hardness ranges, expressed as milligrams per liter of calcium carbonate, are 

as follows: 0–60, soft; 61–120, moderately hard; 121–180, hard; greater than 

180, very hard (Hem, 1985).

3

The SMCLs are nonenforceable Federal guidelines regarding cosmetic 

effects (such as tooth or skin discoloration) or aesthetic effects (such as taste, 

odor, or color) of drinking water. At high constituent concentrations and/or 

values, health implications as well as aesthetic degradation may be present. 

SMCLs were established as guidelines for the States by the U.S. Environmental 

Protection Agency (1992).
?

?

NGVD 29

-100

-200

-300

-400

-500

-600

-700

-800

-900

-1,000

Figure 3. Generalized north-to-south hydrogeologic section through

northern Jefferson Parish, Louisiana (modified from Dial and Tomaszewski, 1988).

Trace of section shown on figure 1. 

Vertical datum is National Geodetic

 Vertical Datum of 1929 (NGVD 29)

VERTICAL SCALE GREATLY EXAGGERATED

Norco aquifer

Gonzales-New Orleans aquifer

Gonzales-New

Orleans aquifer

Freshwater

Freshwater

Freshwater

Saltwater

Saltwater

Saltwater

Gramercy aquifer

Shallow aquifers of the New Orleans area

Confining clays

Confining clays

FEET

NGVD 29

-100

-200

-300

-400

-500

-600

-700

-800

-900

-1,000

FEET

A A'

NORTH SOUTH

Land Surface

Lake

Pontchartrain

Mississippi

River

0

0

4 Miles

4 Kilometers

EXPLANATION

? Hydrogeologic contact uncertain 

Mostly clay

Freshwater in sand

Saltwater in sand

Figure 3. Generalized north-to-south hydrogeologic section 

through northern Jefferson Parish, Louisiana (modified from Dial 

and Tomaszewski, 1988). Trace of section shown on figure 1.

Gonzales-New Orleans Aquifer

The Gonzales-New Orleans aquifer is continuous 

throughout northern Jefferson Parish (Tomaszewski, 2003). 

The top of the aquifer ranges from about 500 ft below NGVD 

29 along the shore of Lake Pontchartrain to about 650 ft 

below NGVD 29 near the Mississippi River. The base of 

the aquifer ranges from about 700 ft below NGVD 29 near 

Lake Pontchartrain to about 850 ft below NGVD 29 near the 

Mississippi River. The thickness of the aquifer is variable 

but generally is about 200 ft (Prakken, 2009), and sand in 

the aquifer is fine to medium grained in northern Jefferson 

Parish (Dial and Tomaszewski, 1988). Fresh groundwater is 

present in the Gonzales-New Orleans aquifer only in parts of 

northern Jefferson Parish located north of the Mississippi River 

and east of Kenner (fig. 1). The aquifer generally contains 

saltwater south of the Mississippi River and in northwestern 

Jefferson Parish. 

State well registration records listed 54 active water wells 

screened in the Gonzales-New Orleans aquifer in Jefferson 

Parish in 2009, including 36 industrial, 10 irrigation, 4 power 

generation, 3 public supply, and 1 domestic. Depths of these 

wells ranged from 557 to 878 ft below land surface with a 

median depth of 764 ft. The records indicated that yields from 

wells screened in the Gonzales-New Orleans aquifer range 

from 20 to 2,400 gal/min (Louisiana Department of Natural 

Resources, 2009). In 2010, groundwater withdrawals from 

the Gonzales-New Orleans aquifer in Jefferson Parish totaled 

about 7.09 Mgal/d (table 1) and included 2.24 Mgal/d for 

industrial, 4.79 Mgal/d for power generation, 0.01 Mgal/d for 

rural domestic, and 0.04 Mgal/d for general irrigation. 

In 2008, there were two major water withdrawal centers 

in the parish: one center was located about 1 mi southwest of 

Bridge City (about 1.8 Mgal/d withdrawn in 2007), and the 

other center was located about 1 mi northeast of Bridge City 

(an estimated 3.9 Mgal/d withdrawn in 2007). The GonzalesYear

Well: Jf-186

Altitude of land surface: 5 feet below NGVD 29

Well depth: 325 feet below land surface

Well: Jf-156

Altitude of land surface: 9 feet above NGVD 29

Well depth: 780 feet below land surface

Well: Jf-178

Altitude of land surface: 0 feet above NGVD 29

Well depth: 700 feet below land surface

0

-10

-20

-30

-40

-50

-60

-70

-80

-90

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015

Water level, in feet below National Geodetic

Vertical Dataum of 1929 (NGVD 29)

Figure 4. Water levels 

in well Jf-186 screened 

in the Norco aquifer 

and wells Jf-156 and 

Jf-178 screened in the 

Gonzales-New Orleans 

aquifer in Jefferson 

Parish, Louisiana (see 

fig. 1 for well locations; 

U.S. Geological Survey, 

2012). Land surface is 

measured in feet above 

the National Geodetic 

Vertical Datum of 1929 

(NGVD 29).
New Orleans aquifer produced saltwater at both of these 

centers (Prakken, 2009). In 2008, water levels in the GonzalesNew Orleans aquifer generally ranged from about 16 ft below 

NGVD 29 in northwestern Jefferson Parish to about 47 ft below 

NGVD 29 near Bridge City. The general direction of flow in the 

Gonzales-New Orleans aquifer north of the Mississippi River 

was toward the east-southeast (Prakken, 2009). 

Water levels in the aquifer generally have risen since the 

1970s in response to reduced withdrawals. Water levels in the 

Gonzales-New Orleans aquifer at well Jf-156, located north of 

Bridge City and the Mississippi River (fig. 1), have risen about 

49 ft since the mid 1970s (fig. 4). Water levels in well Jf-178, 

located in northwestern Jefferson Parish along the shore of Lake 

Pontchartrain (fig. 1), have risen about 10 ft since 1997 (fig. 4). 

A statistical summary of selected water-quality 

characteristics for freshwater samples from 28 wells screened 

in the Gonzales-New Orleans aquifer is listed in table 3. Based 

on median values of chemical constituents, freshwater from the 

aquifer is generally soft and generally does not exceed SMCLs 

for drinking water for pH and concentrations of iron and 

manganese. Dissolved solids concentrations are generally less 

than the SMCL of 500 mg/L but locally may exceed this level. 

Freshwater in the aquifer has a yellow color and exceeds the 

SMCL of 15 platinum cobalt units.

Surface-Water Resources 

The Mississippi River is the primary source of fresh 

surface water in Jefferson Parish (table 1). In 2010, about 

810 Mgal/d of surface water were withdrawn from the 

Mississippi River in the parish, including about 65.0 Mgal/d 

for public-supply, 4.19 Mgal/d for industrial use, and 

740 Mgal/d for power generation. Most surface water 

withdrawn for power generation is used for cooling purposes 

and is returned to its source after use (Sargent, 2011). In 

2010, about 0.04 Mgal/d were withdrawn in Jefferson Parish 

from miscellaneous streams for livestock. Notable surfacewater bodies in or bordering Jefferson Parish include Lake 

Pontchartrain, Lake Cataouatche, Lake Salvador, Little 

Lake, Barataria Bay, and the Gulf of Mexico (fig. 1). There 

were no reported withdrawals from these sources in 2010. 

Water samples collected and analyzed during 

1977–2009 indicated that water in the Mississippi River 

at Belle Chasse (fig. 1) is generally hard and generally 

does not exceed the SMCLs for pH and concentrations 

of chloride, sulfate, and iron (table 4). Dissolved oxygen 

concentration is generally greater than 5 mg/L, which is 

considered the minimum value for a diversified population 

of fresh, warmwater biota, including sport fish (Louisiana 

Department of Environmental Quality, 2008). Mississippi 

River discharge data are not available for Jefferson Parish, 

but the average flow of the Mississippi River near Red 

River Landing, about 200 river miles upstream of the 

parish (fig. 1, index map), was about 460,000 cubic feet per 

second (about 298,000 Mgal/d) during the period 1928–76 

(Wells, 1980). The flow in the Mississippi River at Red 

River Landing (07373290) is representative of flows in 

Jefferson Parish because there are no major tributaries or 

distributaries, and the river is mostly leveed between the 

landing and the parish.

Table 3. Summary of selected water-quality characteristics for freshwater in the Gonzales-New Orleans aquifer in Jefferson Parish, 

Louisiana, 1940–2008 (U.S. Geological Survey, 2009).

[Values are in milligrams per liter, except as noted. °C, degrees Celsius; PCU, platinum cobalt units; μS/cm, microsiemens per centimeter; SU, standard units; 

CaCO3, calcium carbonate; μg/L, micrograms per liter; SMCL, Secondary Maximum Contaminant Level established by the U.S. Environmental Protection 

Agency, (2012); NA, not applicable]

Temperature 

(°C)

Color

(PCU)

Specific 

conductance, 

field

(μS/cm at 25 °C)

pH,

field

(SU)

Hardness 

(as CaCO3

)

Chloride,

filtered

(as Cl)

Iron, 

filtered 

(μg/L as 

Fe)

Manganese, 

filtered

(μg/L as Mn)

Dissolved 

solids, 

filtered

Gonzales-New Orleans aquifer (28 wells)

Median 25.0 100 786 8.3 16 88 80 20 422

10th percentile 24.0 60 639 7.8 9 56 60 10 381

90th percentile 25.5 190 976 8.5 26 120 120 30 544

Number of samples 21 22 20 21 22 28 10 10 14

Percentage of 

samples that do not 

exceed SMCLs

NA 0 NA 90 NA 100 90 100 71

SMCLs

NA 15 NA 6.5–8.5 NA 250 300 50 500
Table 4. Summary of selected water-quality characteristics for the Mississippi River at Belle Chasse, Louisiana, 1977–2009.

[Values are in milligrams per liter, except as noted. μS/cm, microsiemens per centimeter; °C, degrees Celsius; SU, standard units; CaCO3, calcium carbonate;

μg/L, micrograms per liter; <, less than; SMCL, Secondary Maximum Contaminant Level established by the U.S. Environmental Protection Agency (2012);

NA, not applicable]

Specific 

conductance, field

(μS/cm at 

25 °C)

Oxygen,

dissolved

pH,

field

(SU)

Hardness (as 

CaCO3

)

Magnesium,

filtered

(as Mg)

Sodium,

filtered

(as Na)

Chloride,

filtered

(as Cl)

Sulfate,

filtered

(as SO4

)

Iron,

filtered

(μg/L

as Fe)

Mississippi River at Belle Chasse, Louisiana1

Median 408 8.2 7.7 150 12 22 28 48 15

10th percentile 316 6.1 7.2 120 9.3 13 17 34 <3

90th percentile 521 11.7 7.9 180 16 36 42 70 42

Number of samples 189 184 188 182 182 182 182 182 121

Percentage of samples 

that do not exceed 

SMCLs

NA NA 100 NA NA NA 99 100 100

SMCLs

NA NA 6.5–8.5 NA NA NA 250 250 300

1

Station number 07374525 (U.S. Geological Survey, 2009; specific data at http://nwis.waterdata.usgs.gov/la/nwis/qwdata/?site_no=07374525). 

References Cited

Dial, D.C., 1983, Ground-water data for the Mississippi 

River parishes in the greater New Orleans area, Louisiana: 

Louisiana Department of Transportation and Development, 

Office of Public Works Water Resources Basic Records 

Report no. 11, 47 p. 

Dial, D.C., and Kilburn, Chabot, 1980, Ground-water resources 

of the Gramercy area, Louisiana: Louisiana Department of 

Transportation and Development, Office of Public Works 

Water Resources Technical Report no. 24, 39 p. 

Dial, D.C., and Tomaszewski, D.J., 1988, Geohydrology, water 

quality, and effects of pumpage on the New Orleans aquifer 

system, northern Jefferson Parish, Louisiana: U.S. Geological 

Survey Water-Resources Investigations Report 88–4097, 

34 p., accessed August 6, 2012, at http://pubs.usgs.gov/

wri/1988/4097/report.pdf. 

Hem, J.D., 1985, Study and interpretation of the chemical 

characteristics of natural water (3d ed.): U.S. Geological 

Survey Water-Supply Paper 2254, 264 p., accessed February 

20, 2013, at http://pubs.er.usgs.gov/publication/wsp2254.

Hosman, R.L., 1972, Ground-water resources of the Norco 

area, Louisiana: Department of Conservation, Louisiana 

Geological Survey, and Louisiana Department of Public 

Works Water Resources Bulletin no. 18, 61 p. 

Louisiana Department of Environmental Quality, 2008, 

Environmental Regulatory Code, Title 33, Part IX, Subpart 1, 

accessed June 9, 2009, at http:www.deq.louisiana.gov/portal/

tabid/1674/Default.aspx.

Louisiana Department of Natural Resources, 2009, Strategic 

Online Natural Resources Information System (SONRIS): 

Louisiana Department of Natural Resources database, 

accessed July 1, 2009, at http://sonris.com/.

Prakken, L.B., 2009, Groundwater resources in the New 

Orleans area, 2008: Louisiana Department of Transportation 

and Development Water Resources Technical Report no. 80, 

36 p. 

Sargent, B.P., 2011, Water use in Louisiana, 2010: Louisiana 

Department of Transportation and Development Water 

Resources Special Report no. 17, 135 p. 

Tomaszewski, D.J., 2003, Ground-water resources along the 

lower Mississippi River, southeastern Louisiana: Louisiana 

Department of Transportation and Development Water 

Resources Technical Report no. 69, 23 p. 

U.S. Environmental Protection Agency, 1992, Secondary 

Drinking Water Regulations—Guidance for nuisance 

chemicals: U.S. Environmental Protection Agency 

publication EPA 810/K-92-001, 4 p., accessed September 

28, 2011, at http://water.epa.gov/drink/contaminants/

secondarystandards.cfm. 
U.S. Environmental Protection Agency, 2012, 2012 Edition 

of the drinking water standards and health advisories: U.S. 

Environmental Protection Agency publication EPA 822-S12-001, Office of Water, 12 p., accessed August 7, 2012, 

at http://water.epa.gov/action/advisories/drinking/upload/

dwstandards2012.pdf.

U.S. Geological Survey, 2009, Water quality samples for 

Louisiana: National Water Information System Web Interface, 

accessed June 2, 2009, at http://nwis.waterdata.usgs.gov/la/

nwis/qwdata. 

U.S. Geological Survey, 2012, Groundwater levels for 

Louisiana: National Water Information System Web Interface, 

accessed August 6, 2012, at http://nwis.waterdata.usgs.gov/la/

nwis/gwlevels. 

Wells, F.C., 1980, Hydrology and water quality of the lower 

Mississippi River: Louisiana Department of Transportation 

and Development, Office of Public Works Water Resources 

Technical Report no. 21, 83 p. 

This fact sheet was published by the U.S. 

Geological Survey, in cooperation with the Louisiana 

Department of Transportation and Development 

(DOTD). Thanks are given to Zahir “Bo” Bolourchi, 

Director, Water Resources Programs, Louisiana 

Department of Transportation and Development, who 

contributed to the content of the fact sheet.

By Lawrence B. Prakken and John K. Lovelace

For additional information, contact: 

Director, USGS Louisiana Water Science Center

3535 S. Sherwood Forest Blvd., Suite 120

Baton Rouge, LA 70816

E-mail: dc_la@usgs.gov

Fax: (225) 298–5490

Telephone: (225) 298–5481

Home Page: http://la.water.usgs.gov

ISSN 2327–6916 (print)

ISSN 2327–6932 (online)

http://dx.doi.org/10.3133/fs20133073