U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2014–3017

May 2014

Prepared in cooperation with the Louisiana Department of Transportation and Development 

Water Resources of Orleans Parish, Louisiana

Introduction

Information concerning the availability, use, and quality of 

water in Orleans Parish, Louisiana (fig. 1), is critical for proper 

water-supply management. The purpose of this fact sheet is to 

present information that can be used by water managers, parish 

residents, and others for stewardship of this vital resource. 

Information on the availability, past and current use, use trends, 

and water quality from groundwater and surface-water sources 

in the parish is presented. 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 the information 

presented here. 

In 2010, about 615 million gallons per day (Mgal/d) 

of water were withdrawn in Orleans Parish, including about 

602 Mgal/d from surface-water sources and about 13.0 Mgal/d 

from groundwater sources1

 (table 1). Power generation accounted 

for about 75 percent (464 Mgal/d) of the total water withdrawn. 

Other categories of use in 2010 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 in 1985 at 

nearly 1,050 Mgal/d. 

1

Tabulation of numbers across text and tables may result in different totals 

because of rounding; nonrounded numbers are used for calculation of totals.

0 5 10 MILES

0 5 10 KILOMETERS

EXPLANATION

Approximate freshwater extent of the

 Gonzales-New Orleans aquifer in

 Orleans Parish (modified from

 Prakken, 2009)

Marsh and swamp

Line of section (see fig. 3)

Well for which hydrograph is shown

 (see fig. 4)

Surface-water quality site and number

 (see table 4)

Surface-water discharge site and number C

07373291

#

O

07374508

Or-206

A'A

Base modified from U.S. Geological Survey digital data

Albers Equal-Area Conic projection

North American Datum of 1983

TEXAS

ARKANSAS MISSISSIPPI

LOUISIANA

ORLEANS

07373291C PARISH

ST BERNARD

PARISH

ORLEANS PARISH

Lake

Borgne

Lake Pontchartrain

ST TAMMANY PARISH

Mississippi River

Inner Harbor

Navigation Canal

Lake

St Catherine

JEFFERSON PARISH PLAQUEMINES

 PARISH

Mississippi River Gulf Outlet

Mississippi River Gulf Outlet

90°10' 90°00' 89°50' 89°40'

30°10'

30°00'

Algiers

Michoud

O

O

Or-42

Or-206

Or-175

07374508

300024089560500

#

#

#

A

A'

Groundwater withdrawal centers

Gulf Intracoastal Waterway Gulf Intracoastal Waterway

47 .90

§ ̈¦10

§ ̈¦510

§ ̈¦610

.90

47

Figure 1. Location of study area, Orleans Parish, Louisiana. 
Table 1. Water withdrawals, in million gallons per day, by source 

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

Aquifer or

surface-water body Groundwater Surface water

Gramercy aquifer 0.02

Gonzales-New Orleans aquifer 12.93

Gulf Intracoastal Waterway 453.20

Mississippi River 149.14

Other water bodies 0.02

Total 12.95 602.37

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

use category in Orleans Parish, Louisiana, 2010 (modified from 

Sargent, 2011).

Use category Groundwater Surface water Total

Public supply 0.00 149.14 149.14

Industrial 1.88 0.00 1.88

Power generation 10.87 453.20 464.07

Rural domestic 0.17 0.00 0.17

Livestock 0.00 0.02 0.03

General irrigation 0.02 0.00 0.02

Total 12.95 602.37 615.31

0

200

400

600

800

1,000

1,200

Year

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Annual withdrawals, in million gallons per day

Groundwater

Surface water

EXPLANATION

Figure 2. Water withdrawals in Orleans Parish, Louisiana, 

1960–2010 (Sargent, 2011).

Groundwater Resources 

The primary fresh groundwater resource underlying Orleans 

Parish is the Gonzales-New Orleans aquifer (fig. 3). Other 

aquifers underlying the parish include Mississippi River point 

bar deposits, the shallow aquifers of the New Orleans area, the 

Gramercy and Norco aquifers, and the “1,200-foot” sand of 

the New Orleans area. These other aquifers generally contain 

very hard2 water with 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]). Because of these water-quality concerns, these aquifers 

generally are not utilized for water supply in Orleans Parish 

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

groundwater also is available from the Evangeline equivalent 

aquifer system at depths between 2,000 and 2,500 feet (ft) below 

the National Geodetic Vertical Datum of 1929 (NGVD 29) in a 

small area in the extreme northeastern part of the parish (Smoot, 

1988). Because of the limited extent of the Evangeline equivalent 

aquifer system within the parish, it is not utilized for water supply 

in Orleans Parish and is not discussed further in this report.

State well-registration records listed 244 active water wells 

in Orleans Parish in 2009, including 162 domestic, 46 industrial, 

17 public supply, 15 irrigation, and 4 power generation 

(Louisiana Department of Natural Resources, 2009). In 2010, 

groundwater withdrawals for various uses included industrial, 

power generation, rural domestic, and general irrigation (table 2). 

Almost all groundwater withdrawals in Orleans Parish came from 

the Gonzales-New Orleans aquifer; water withdrawals from the 

Gramercy aquifer totaled about 0.02 Mgal/d (table 1). 

Gonzales-New Orleans Aquifer 

The Gonzales-New Orleans aquifer is continuous throughout 

Orleans Parish and dips in a southerly direction (Tomaszewski, 

2003). The aquifer consists of mostly fine to medium sand of 

uniform texture (Dial and Sumner, 1989). The top of the aquifer is 

about 230 ft below NGVD 29 in the extreme northeastern corner 

of the parish (Griffith, 2003) and about 650–700 ft below NGVD 

29 in the southern part of the parish (Tomaszewski, 2003). In 

northeastern Orleans Parish, the Gonzales-New Orleans aquifer is 

composed of two distinct hydrologic units: a thick basal sand unit 

bearing saltwater and a thinner upper sand unit bearing freshwater 

(fig. 3) (Rollo, 1966). Thickness of the basal sands of the aquifer 

is variable but is generally about 150–200 ft or more in Orleans 

Parish (Prakken, 2009). Locally, sand lenses and sand streaks 

thicken the aquifer. 

The Gonzales-New Orleans aquifer receives recharge 

from precipitation and infiltration in areas where it outcrops or 

subcrops north of Lake Pontchartrain (Dial and Tomaszewski, 

1988). The aquifer also receives recharge through overlying and 

underlying confining units and from adjacent aquifers (Dial and 

Tomaszewski, 1988). Discharge from the aquifer is primarily by 

withdrawals from wells.

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).
WEST

A

EAST

A’

Figure 3. Hydrogeologic section A-A’ showing major sand units from central Orleans Parish to northeastern Orleans Parish, Louisiana 

(modified from Prakken, 2009). Trace of section shown on figure 1.

Gonzales-New Orleans

aquifer

Norco aquifer thin or missing

Gramercy aquifer thin or missing

(Location of section shown on fig. 1)

FEET

+50

-200

-100

NGVD 29

-300

-400

-500

-600

-700

-800

-900

-1000

FEET

+50

-200

-100

NGVD 29

-300

-400

-500

-600

-700

-800

-900

-1000

Or-192 Or-112 Or-170 Or-51 Or-220 Or-172

Gonzales-New Orleans

aquifer

Upper sand unit of the

Gonzales-New Orleans

aquifer

?

0

0

5 MILES

5 KILOMETERS

?

?

No data

Clay Saltwater in sand

Screened interval

Approximate top of “1,200-foot” 

sand–queried (?) where uncertain

Freshwater in sand

EXPLANATION

VERTICAL DATUM IS NATIONAL GEODETIC VERTICAL DATUM OF 1929 (NGVD 29)

Figure 3. Hydrogeologic section A-A’ showing major sand units from central to northeastern Orleans Parish, Louisiana (modified from 

Prakken, 2009). Trace of section shown on figure 1.

As discussed previously, fresh groundwater is available 

from the Gonzales-New Orleans aquifer in Orleans Parish, but 

saltwater also is present in the aquifer. Within the GonzalesNew Orleans aquifer, the base of freshwater generally ranges 

from about 350 ft below NGVD 29 in northeastern Orleans 

Parish to about 750 ft below NGVD 29 in western areas of the 

parish. In general, the aquifer contains freshwater in areas of 

the parish north of U.S. Highway 90 and saltwater in areas to 

the south (fig. 1). 

State well-registration records listed 206 active wells 

screened in the Gonzales-New Orleans aquifer in Orleans 

Parish in 2009, including 131 domestic, 42 industrial, 16 public 

supply, 13 irrigation, and 4 power generation. Depths of these 

wells ranged from 220 to 815 ft below land surface, with a 

median depth of 490 ft. In Orleans Parish, reported well yields 

have ranged from 1 to 2,600 gallons per minute (Louisiana 

Department of Natural Resources, 2009). 

In 2010, over 98 percent of withdrawals from the GonzalesNew Orleans aquifer in the parish occurred at two locations 

where the aquifer contains only saltwater. About 10.9 Mgal/d 

were withdrawn at a powerplant located about 1.5 miles 

(mi) southwest of Michoud (fig. 1) near the Gulf Intracoastal 

Waterway (GIWW), and about 1.88 Mgal/d were withdrawn in 

an industrial area located about 1 mi southeast of Michoud. 

In 2008, water levels in the Gonzales-New Orleans aquifer 

in Orleans Parish ranged from about 21 ft below NGVD 29 

in northeastern Orleans Parish to about 145 ft below NGVD 

29 near Michoud (Prakken, 2009), and the general direction 

of water movement in the aquifer was radially toward the 

withdrawal center southwest of Michoud. Water levels in the 

Gonzales-New Orleans aquifer generally have risen since the 

1970s in response to reduced groundwater withdrawals. Total 

groundwater withdrawals in Orleans Parish, which have been 

primarily from the Gonzales-New Orleans aquifer, decreased 

from 43.4 Mgal/d in 1970 (Dial, 1970) to 12.95 Mgal/d in 2010 

(Sargent, 2011) (fig. 2). Water levels at well Or-42, located south 

of the Mississippi River in Algiers (fig. 1), have risen about 70 ft 

since 1970 (fig. 4). Water levels in well Or-206, located on the 

east bank of the Inner Harbor Navigation Canal (fig. 1), rose 

about 119 ft from 1972 to 2011 (fig. 4). Water levels in the well 

rose abruptly about 18 ft in 2005 after Hurricane Katrina. Water 

levels in well Or-175, located in northeastern Orleans Parish (fig. 

1) about 8 mi from any pumping center, generally have changed 

little since 1970 (fig. 4). 
Year

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015

Water level, in feet 

-175

-150

-125

-100

-75

-50

-25

0

Well: Or-175

Altitude of land surface: 10 feet above NGVD 29

Well depth: 449 feet below land surface

Well: Or-42

Altitude of land surface: 10 feet above NGVD 29

Well depth: 775 feet below land surface

Well: Or-206

Altitude of land surface: 4 feet above NGVD 29

Well depth: 647 feet below land surface

Figure 4. Water levels in wells Or-175, Or-42, and Or-206 screened in the

Gonzales-New Orleans aquifer in Orleans Parish, Louisiana (see figure 1 for 

well locations; U.S Geological Survey, 2012a, b, c). Land surface and water level

 are measured in feet relative to the National Geodetic Vertical Datum of 1929 (NGVD 29). 

No data

Hurricane Katrina August 2005

Figure 4. Water levels in wells Or-175, Or-42, and Or-206 screened in the Gonzales-New Orleans aquifer in Orleans Parish, Louisiana (see fig. 

1 for well locations; U.S. Geological Survey, 2012a, b, c). Land surface and water level are measured in feet relative to the National Geodetic 

Vertical Datum of 1929 (NGVD 29).

A statistical summary of selected water-quality 

characteristics for freshwater samples collected from 84 wells 

screened in the Gonzales-New Orleans aquifer in Orleans Parish 

is presented in table 3. The median value for hardness fell 

within the soft range. Median values for iron and manganese 

fell below the U.S. Environmental Protection Agency’s 

Secondary Maximum Contaminant Levels (SMCLs).3

 Chloride 

concentrations were below the SMCL and tended to increase 

toward saltwater areas. Dissolved solids concentrations generally 

exceed the SMCL of 500 mg/L. Water in the aquifer has a yellow 

color and exceeds the SMCL of 15 platinum cobalt units. 

Surface-Water Resources

In 2010, about 602 Mgal/d of surface water were 

withdrawn in the parish, including about 453 Mgal/d for power 

generation, 149 Mgal/d for public supply, and 0.02 Mgal/d for 

livestock (table 2). Although Orleans Parish extends into Lake 

Pontchartrain, there were no reported water withdrawals from 

the lake. All public-supply water came from the Mississippi 

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 concentrations or values, 

health implications as well as aesthetic degradation may result. SMCLs were 

established as guidelines for the States by the U.S. Environmental Protection 

Agency (1992).

River, which is the primary source of fresh surface water in 

the parish. Water samples analyzed during the period 1967–88 

indicated that water in the Mississippi River at New Orleans 

(site number 07374508) (fig. 1) is generally hard and does 

not exceed the SMCLs for pH and concentrations of chloride, 

sulfate, and iron (table 4). Dissolved oxygen concentrations 

are 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 

Orleans Parish, but the average flow of the Mississippi River 

near Red River Landing (site number 07373291), about 

210 river miles upstream of the parish (fig. 1, index map), was 

about 460,000 cubic feet per second (about 298,000 Mgal/d) 

for the period 1928–76 (Wells, 1980). The flow in the 

Mississippi River near Red River Landing is representative of 

flows in Orleans Parish because there are no major tributaries 

or distributaries, and the river is mostly leveed between the 

landing and the parish.

The GIWW is a deepwater navigation channel that 

extends through much of Orleans Parish and intersects with 

the Mississippi River (fig. 1). Locks prevent continuous 

water exchange between the GIWW and the river. In 2010, 

about 453 Mgal/d were withdrawn from the GIWW (table 

1) at a power-generation plant near Michoud. Most surface 

water withdrawn for power generation was used for cooling 

and returned to the GIWW after use (Sargent, 2011). Water 

samples analyzed during the period 1974–84 indicated that 
Table 3. Summary of selected water-quality characteristics for freshwater in the Gonzales-New Orleans aquifer in Orleans Parish, 

Louisiana, 1942–2008 (U.S. Geological Survey, 2011).

[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, 2011; 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 (84 wells)

Median 25.0 160 972.5 8.1 19.5 82.5 140 25 594

10th percentile 23.0 92 721.6 7.2 10 37.6 45 13 438.5

90th percentile 15.5 268 1264 8.3 37 170 975 569 812.5

Number of samples 27 33 40 39 76 84 6 4 22

Percentage of samples 

that do not exceed 

SMCLs

NA 0 NA 100 NA 100 67 75 36

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 and the Gulf Intracoastal Waterway in Orleans 

Parish, Louisiana (U.S. Geological Survey, 2011).

[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, 2011; NA,

not applicable]

Specific 

conductance, field 

(μS/cm at 

25 °C)

Oxygen, 

dissolved

pH,

field

(SU)

Hardness

(as CaCO3)

Calcium,

filtered

(as Ca)

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 New Orleans, 1967–881

Median 406 8.0 7.6 150 41 12 22 24 53 20

10th percentile 310 6.1 7.1 120 33 8.7 14 16 40 <10

90th percentile 498 11.0 8.0 180 48 15 33 34 74 50

Number of samples 198 158 186 181 181 181 180 183 182 43

Percentage of 

samples that 

do not exceed 

SMCLs

NA NA 100 NA NA NA NA 100 100 100

Gulf Intracoastal Waterway at New Orleans Public Service Incorporated (NOPSI) Plant near Paris Road at New Orleans, 1974–842

Median 13,400 8.2 7.6 1,400 97 280 3,000 4,400 570 30

10th percentile 3,690 6.3 7.4 390 38 67 1,400 1,600 140 <10

90th percentile 20,700 10.2 7.9 2,400 150 480 3,800 7,000 980 70

Number of samples 126 120 126 120 111 112 48 125 123 125

Percentage of 

samples that 

do not exceed 

SMCLs

NA NA 100 NA NA NA NA 0 16 99

SMCLs

NA NA 6.5–8.5 NA NA NA NA 250 250 300

1

Site number 07374508 (U.S. Geological Survey, 2010; specific data at http://nwis.waterdata.usgs.gov/usa/nwis/qwdata/?site_no=07374508).

2

Site number 300024089560500 (U.S. Geological Survey, 2009; specific data at http://nwis.waterdata.usgs.gov/usa/nwis/qwdata/?site_no=300024089560500).
water in the GIWW, east of the Mississippi River, at the former 

New Orleans Public Service Incorporated Plant4 (site number 

300024089560500) (fig. 1) is generally very hard and does 

not exceed the SMCL for pH (table 4). The water is salty with 

chloride concentrations well above the 250 mg/L SMCL. The 

median value for sulfate concentrations exceeds the SMCL 

of 250 mg/L. Dissolved oxygen concentrations are generally 

greater than 5 mg/L. 

4

New Orleans Public Service Incorporated Plant is now known as Entergy 

References Cited 

Dial, D.C., 1970, Pumpage of water in Louisiana, 1970: Department of 

Conservation, Louisiana Geological Survey, and Louisiana Department 

of Public Works Water Resources Pamphlet no. 26, 10 p.

Dial, D.C., and Sumner, D.M., 1989, Geohydrology and simulated effects 

of pumpage on the New Orleans aquifer system at New Orleans, 

Louisiana: Louisiana Department of Transportation and Development 

Water Resources Technical Report no. 46, 54 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.

Griffith, J.M., 2003, Hydrogeologic framework of southeastern Louisiana: 

Louisiana Department of Transportation and Development Water 

Resources Technical Report no. 72, 21 p., 18 pls. 

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.

Louisiana Department of Environmental Quality, 2008, Environmental 

Regulatory Code, Title 33, Part IX, Subpart 1: Baton Rouge, Louisiana 

Department of Environmental Quality, 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 March 12, 2010, 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. 

Rollo, J.R., 1966, Ground-water resources of the greater New Orleans area, 

Louisiana: Department of Conservation, Louisiana Geological Survey, 

and Louisiana Department of Public Works Water Resources Bulletin 

no. 9, 69 p. 

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

of Transportation and Development Water Resources Special Report no. 

17, 135 p. 

Smoot, C.W., 1988, Louisiana hydrologic atlas map no. 3—Altitude of 

the base of freshwater in Louisiana: U.S. Geological Survey WaterResources Investigations Report 86-4314, 1 sheet, accessed November 

2, 2011, at http://pubs.er.usgs.gov/publication/wri864314.

Michoud Plant.

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, 2011, 2011 Edition of the drinking 

water standards and health advisories: U.S. Environmental Protection 

Agency publication EPA 820-R-11-002, Office of Water, 12 p., accessed 

September 2, 2011, at http://water.epa.gov/action/advisories/drinking/

upload/dwstandards2011.pdf. 

U.S. Geological Survey, 2011, Water quality samples for Louisiana: 

National Water Information System Web Interface, accessed November 

18, 2011, at http://nwis.waterdata.usgs.gov/la/nwis/qwdata/. 

U.S. Geological Survey, 2012a, Groundwater levels for Louisiana [data for 

USGS 300525089464001 Or-175]: accessed March 21, 2012, at http://

nwis.waterdata.usgs.gov/la/nwis/gwlevel/?site_no=300525089464001. 

U.S. Geological Survey, 2012b, Groundwater levels for Louisiana [data for 

USGS 295652090020101 Or-42]: accessed March 21, 2012, at http://

nwis.waterdata.usgs.gov/la/nwis/gwlevel/?site_no=295652090020101. 

U.S. Geological Survey, 2012c, Groundwater levels for Louisiana [data for 

USGS 300027090013201 Or-206]: accessed March 21, 2012, at http://

nwis.waterdata.usgs.gov/la/nwis/gwlevel/?site_no=300027090013201.

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, DOTD, who contributed to the 

content of the fact sheet.

By Lawrence B. Prakken, Vincent E. White, 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/110.3133/fs20143017