U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2020-3002

March 2020

Prepared in cooperation with the Louisiana Department of Transportation and Development 

Water Resources of Union Parish, Louisiana

Introduction

Information concerning the availability, use, and quality of 

water in Union 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. In 

2014, about 4.88 million gallons per day (Mgal/d) of water were 

withdrawn in Union Parish: 4.70 Mgal/d from groundwater 

sources and 0.18 Mgal/d from surface-water sources1 (table 1).

1

Withdrawals for public-supply use accounted for about 89 percent 

(4.36 Mgal/d) of the total water withdrawn (table 2). Other 

categories of use included industrial, rural domestic, livestock, rice 

irrigation, and general irrigation. Water-use data collected at 5-year 

intervals from 1960 to 2010 and again in 2014 indicated that water 

withdrawals peaked in 2000 at about 8.89 Mgal/d (fig. 2). 

1

Water-withdrawal data are based on estimated or reported site-specific data 

and aggregated data, which are distributed to sources. For a full description of 

water-use estimate methodology, see “Data Collection” in Collier and Sargent 

(2018). Tabulation of numbers in text and tables may result in different totals 

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

Figure 1. Location of study area, Union Parish, Louisiana.

Groundwater Resources 

The primary freshwater-bearing aquifer in Union Parish is the 

Sparta aquifer. The Sparta aquifer underlies the Cook Mountain 

aquifer, which is present in thin lenses of fine sands within the 

Cook Mountain confining unit and can supply limited amounts of 

freshwater (Snider and others, 1972). The Cook Mountain aquifer 

is not discussed further in this publication. The Cockfield aquifer 

and, in the northeastern part of Union Parish, the Upland terrace 

and alluvial aquifers overlie the Cook Mountain confining unit 

(figs. 1 and 3). The Cane River confining unit and Carrizo-Wilcox 

aquifer underlie the Sparta aquifer throughout the parish but only 

contain saltwater. The altitude of the base of fresh groundwater 

(water with a chloride concentration of 250 milligrams per liter 

[mg/L] or less) within the Sparta aquifer ranges from about 

500 feet (ft) below the National Geodetic Vertical Datum of 1929 

(NGVD 29) in northwestern Union Parish to about 600 ft below 

NGVD 29 towards the east-southeast (Smoot, 1988).

0 5 10 MILES

0 5 10 KILOMETERS

A

A'

167

167

2

2

2

2

33

15

33

549

143 2

07364700

07366000

07366200

07365500

Un-26

Bernice

Laran

Lillie

ARKANSAS

LOUISIANA LOUIS NA

MOREHOUSE

PARISH

OUACHITA

PARISH

CLAIBORNE

PARISH UNION

PARISH

LINCOLN

PARISH

LINCOLN Bayou PARISH D’Arbonne

subbasin

Lower OuachitaBayou De Loutre

subbasin

Bayou D’Arbonne

Lake

Corney

Lake

Little Corney Bayou Little Corney Bayou

Ouachita River

Bayou D’Arbonne

Bayou de Loutre

Bayou D’Arbonne Bayou D’Arbonne

Corney Bayou

Middle Fork Bayou D’ArbonneMiddle Fork Bayou D’Arbonne

92°10' 92°30' 92°20'

92°40'

33°00'

32°50'

32°40'

Approximate altitude of base of fresh

groundwater, in feet below National 

Geodetic Vertical Datum of 1929 

(NGVD 29) (modified from Smoot, 

1988)—Deepest freshwater contained

within the Sparta aquifer

300 to 399

400 to 499

500 to 599

600 to 699

700 to 799 

River subbasin boundary

Line of section (see fig. 3; modified from

Ryals, 1984)

Well for which hydrograph is shown

(see fig. 4)

U.S. Geological Survey surface-water

streamflow site and number

U.S. Geological Survey surface-waterquality site and number (see table 4)

EXPLANATION

A A'

Un-26

07365500

07366000

Base modified from U.S. Geological Survey digital data

Albers Equal-Area Conic projection

North American Datum of 1983

GULF OF MEXICO TEXAS

MISSISSIPPI

ARKANSAS

LOUISIANA

UNION

PARISH
Figure 2. Water withdrawals in Union Parish, Louisiana, 1960–

2014 (U.S. Geological Survey, 2016; Collier 2018).

Figure 3. Idealized west-to-east hydrogeologic section through 

Union Parish, Louisiana, showing aquifer and confining unit 

intervals (individual sand and clay layers not shown). Trace of 

section shown on figure 1.

Sparta Aquifer

The Sparta aquifer provided more than 98 percent of all 

groundwater withdrawn in Union Parish in 2014. The aquifer extends 

across all of Union Parish and is part of a large regional aquifer that 

is present in several States. The Sparta aquifer is composed of fine 

to medium sand with thin layers of clay and lignite (Payne, 1968; 

Snider and others, 1972). The thickness of the Sparta aquifer ranges 

from about 400 ft in much of northwestern and north-central Union 

Parish to about 800 ft in the southeast. The altitude of the base 

of the aquifer ranges from 600 ft below NGVD 29 in the west to 

800 ft below NGVD 29 in the east, and most of the aquifer contains 

freshwater. The transition to saltwater is only marginally present 

along the eastern border of the parish and begins at about 750 ft 

below NGVD 29 (Snider and others, 1972; Ryals, 1984). 

Groundwater

Surface water

EXPLANATION

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2014

Annual withdrawal, in million gallons per day

Year

0

10

1

2

3

4

5

6

7

8

9

Hydrogeologic unit (modified from Ryals, 1984)

Aquifer containing freshwater—Freshwater

contains a chloride concentration of 

250 milligrams per liter or less

Aquifer containing saltwater

Confining unit

Hydrogeologic contact (modified from Ryals,

1984)—Separates hydrogeologic units.

Dashed where approximately located

Approximate freshwater/saltwater interface

(modified from Ryals, 1984, and Smoot, 1988) 

EXPLANATION 

NGVD 29, National Geodetic Vertical Datum of 1929 BEND IN SECTION BEND IN SECTION

BEND INSECTION

Little Corney Bayou

Bayou de Loutre

Ouachita River

0 5 10 MILES

0 5 10 KILOMETERS

VERTICAL SCALE GREATLY EXAGGERATED

NGVD 29 NGVD 29

500

500

1,000

1,500

2,000

2,500

FEET

500

500

1,000

1,500

2,000

2,500

FEET

A A'

WEST EAST

Sparta aquifer

Cane River confining unit

Cockfield aquifer

Carrizo-Wilcox aquifer

Midway confining unit

Cook Mountain confining unit Cook Mountain confining unit

Upland terrace and

alluvial aquifers

Table 1. Water withdrawals, in million gallons per day, by 

source in Union Parish, Louisiana, 2014 (Collier, 2018).

[<, less than]

Aquifer or 

surface-water body Groundwater Surface water

Sparta aquifer 4.64

Cockfield aquifer 0.05

Upland terrace aquifer 0.01

Mississippi River 

alluvial aquifer

<0.01

Miscellaneous streams 0.18

Total 4.70 0.18

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

category in Union Parish, Louisiana, 2014 (Collier, 2018).

[<, less than]

Use category Groundwater Surface water Total

Public supply 4.36 0.00 4.36

Industrial 0.10 0.00 0.10

Rural domestic 0.19 0.00 0.19

Livestock 0.04 0.18 0.22

Rice irrigation 0.00 0.00 0.00

General irrigation 0.00 <0.01 0.00

Total 4.70 0.18 4.88
The primary source of recharge for the Sparta aquifer is 

the infiltration of precipitation in the outcrop areas (Brantly and 

others, 2002). Recharge also occurs by leakage from overlying 

rivers and aquifers. Groundwater generally moves towards the 

central and southeastern parts of the parish, towards Ouachita 

Parish (McGee and Brantly, 2015). Groundwater discharges 

through leakage into the other aquifers and confining units above 

and below the Sparta aquifer and through well withdrawals 

(Payne, 1968).

In 2012, altitudes of water levels in wells screened in the 

Sparta aquifer ranged from about 20 ft below NGVD 29 in the 

northern part of the parish to deeper than 120 ft below NGVD 29 

in the south-central part of the parish (McGee and Brantly, 2015). 

Water levels in the Sparta aquifer at well Un-26, located in the 

southeast corner of Union Parish (figs. 1 and 4), declined by 

more than 50 ft from 1957 to 2003, but have rebounded by about 

12 ft between 2004 and 2016. The recovery is likely a result 

from groundwater conservation efforts in south-central Arkansas 

(Freiwald and Johnson, 2007).

State well-registration records listed 183 active water 

wells screened in the Sparta aquifer in Union Parish in 2017: 

72 public supply wells, 62 irrigation wells, 33 domestic wells, and 

16 industrial wells. Well depths ranged from 82 to 812 ft below 

land surface, and reported yields ranged from 10 to 930 gallons 

per minute (gal/min) (Louisiana Department of Natural Resources, 

2017). In 2014, about 4.64 Mgal/d were withdrawn from the 

Sparta aquifer: 4.36 Mgal/d for public supply, 0.13 Mgal/d for 

rural domestic, 0.10 Mgal/d for industry, and 0.04 Mgal/d for 

livestock (Collier, 2018). 

Cockfield Aquifer

The Cockfield aquifer underlies much of Union Parish and 

provides fresh groundwater to shallow domestic and irrigation 

wells. The aquifer contains mostly fine to medium sand with small 

layers of silt, siltstone, sandstone, and ironstone (Snider and others, 

1972). Aquifer thickness ranges from 0 to 200 ft across the entire 

parish, becoming increasingly thin and then absent in the eastern 

and southeastern parts of the parish. The altitude of the base of the 

aquifer ranges from about 100 ft above NGVD 29 in western Union 

Parish to 100 ft below NGVD 29 towards the east (Ryals, 1984). 

The primary source of recharge for the Cockfield aquifer 

is the infiltration of precipitation. Groundwater generally moves 

downward to the underlying Cook Mountain confining unit or 

towards local streams where discharge results (fig. 3).

State well-registration records listed 37 active water wells 

screened in the Cockfield aquifer in Union Parish in 2017: 

19 domestic wells, 17 irrigation wells, and 1 public-supply 

well. Depths of these wells ranged from 25 to 220 ft below 

land surface, and reported yields ranged from 10 to 125 gal/min 

(Louisiana Department of Natural Resources, 2017). In 2014, about 

0.05 Mgal/d were withdrawn from the Cockfield aquifer, all of 

which was withdrawn for rural domestic use (Collier, 2018). 

Upland Terrace and Alluvial Aquifers

The Upland terrace and alluvial aquifers are the sand and 

gravel component of the terrace and alluvial deposits and are 

present in limited areas of Union Parish along the eastern border 

(fig. 3). Groundwater in the Upland terrace aquifer moves laterally 

to the alluvial aquifers and downward into the underlying units 

(Snider and others, 1972).

Figure 4. Water levels in well Un-26 screened in the Sparta aquifer in Union Parish, Louisiana (see figure 1 for well location; U.S. Geological 

Survey, 2018). 

70

60

50

40

30

20

10

NGVD 29

1956195819601962196419661968197019721974197619781980198219841986198819901992199419961998200020022004200620082010201220142016

Well: Un-26

Aquifer: Sparta aquifer

Altitude of land surface: 134 ft above NGVD 29

Well depth: 745 ft below land surface

Year

Water level, in feet (ft) relative to the National Geodetic

Vertical Datum of 1929 (NGVD 29)
In 2017, State well-registration records for Union Parish 

listed six active water wells screened in the Upland terrace aquifer: 

five domestic wells and one industrial well. Depths of these wells 

ranged from 25 to 69 ft below land surface. Records listed 11 active 

water wells screened in the alluvial aquifers: 1 public supply well, 

4 irrigation wells, and 6 domestic wells. Depths of these wells 

ranged from 26 to 90 ft below land surface, and reported yields 

ranged from 5 to 25 gal/min (Louisiana Department of Natural 

Resources, 2017). In 2014, the Upland terrace aquifer and the 

alluvial aquifers each withdrew about 0.01 Mgal/d for domestic 

purposes (Collier, 2018). 

Groundwater Quality

Groundwater samples were collected during 1905–2016 

from 108 wells screened in the Sparta aquifer and during 

1968–2014 from 7 wells screened in the Cockfield aquifer as 

part of an ongoing program to monitor the State’s groundwater 

resources. These samples had median values that are within the 

U.S. Environmental Protection Agency’s Secondary Maximum 

Contaminant Levels2 (SMCLs) for chloride, sulfate, iron, and 

manganese (table 3). The values for pH exceeded the SMCL of 

6.5–8.5 in 38 percent of samples from the Sparta aquifer and 

71 percent of samples from the Cockfield aquifer. The median 

hardness values of 6 mg/L for the Sparta aquifer and 21 mg/L 

for the Cockfield aquifer were both within the soft3 range. 

Concentrations of dissolved solids exceeded the SMCL in more 

than 70 percent of samples in the Sparta aquifer, but all samples 

from the Cockfield aquifer had concentrations below the SMCL of 

500 mg/L. 

2

The SMCLs are Federal guidelines regarding cosmetic effects (such as 

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

technical effects (such as damage to water equipment or reduced effectiveness 

of treatment for other contaminants) of potential constituents of drinking water. 

SMCLs were established as guidelines by the U.S. Environmental Protection 

Agency (2016). 3

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).

Table 3. Summary of selected water-quality characteristics for freshwater from 108 wells screened in the Sparta aquifer and 7 wells 

screened in the Cockfield aquifer in Union Parish, Louisiana (U.S. Geological Survey, 2018).

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

μg/L, micrograms per liter; SMCL, Secondary Maximum Contaminant Level established by the U.S. Environmental Protection Agency (2016); NA, not applicable]

Temperature

(°C)

Color, 

(platinum 

cobalt 

units)

Specific 

conductance, 

field

(μS/cm at 

25°C)

Dissolved 

oxygen

pH, 

field

(SU)

Hardness

(as 

CaCO3)

Chloride, 

filtered

(as Cl)

Sulfate, 

filtered

(as SO4)

Iron, 

filtered

(μg/L 

as Fe)

Manganese,

filtered

(μg/L as 

Mn)

Dissolved 

solids,

filtered

Sparta aquifer (1905–2016)

Median 24.5 30 1,210 0.3 8.4 6 182 0.27 14 1.7 668.5

10th percentile 22.0 5 703 0.1 7.8 2 37.1 0 6.1 0.6 333.1

90th percentile 25.2 60 1,500 1.5 8.8 15 355 2.96 308 10 807.2

Number of 

samples

142 103 167 56 140 197 240 147 113 83 138

Percentage 

of samples 

that do not 

exceed 

SMCLs

NA 33 NA NA 62 NA 72 100 89 98 28

Cockfield aquifer (1968–2014)

Median NA 5 98 NA 5.9 21 12.5 0.4 70 16.2 86.5

10th percentile NA 0 44.8 NA 5.5 9.4 1.9 0 8 10.8 39

90th percentile NA 12 257 NA 7.5 39 19.8 2.8 232 41 145

Number of 

samples

1 6 7 1 7 8 8 7 7 4 6

Percentage 

of samples 

that do not 

exceed 

SMCLs

NA 100 NA NA 29 NA 100 100 100 100 100

SMCLs NA 15 NA NA 6.5–8.5 NA 250 250 300 50 500
Surface-Water Resources 

Surface-water resources in Union Parish are present in two 

drainage subbasins and generally flow towards the southeastern 

parts of the parish. The Bayou D’Arbonne subbasin (Hydrologic 

Unit Code [HUC] 08040206) drains the west-southwestern 

half of the parish, and the Lower Ouachita-Bayou De Loutre 

subbasin (HUC 08040202) drains the east-northeastern half of the 

parish (fig. 1) (U.S. Geological Survey [USGS], 2018). In 2014, 

0.18 Mgal/d were withdrawn from miscellaneous streams in these 

subbasins for agricultural purposes, including about 0.18 Mgal/d 

for livestock and less than 0.01 Mgal/d for general irrigation 

(tables 1 and 2) (Collier, 2018). 

Bayou D’Arbonne Subbasin 

The Bayou D’Arbonne subbasin covers the southwestern 

half of Union Parish. Major streams in the subbasin in the parish 

include Corney Bayou, Bayou D’Arbonne, and Middle Fork 

Bayou D’Arbonne (fig. 1). The annual average streamflow during 

1956–2018 was 203 cubic feet per second (ft3/s) at the Little 

Corney Bayou near Lillie (USGS site number 07366200; fig. 1). 

During this same period, the highest monthly average streamflow 

was 392 ft3/s in March and the lowest was 28 ft3/s during August 

(USGS, 2018). During 1941–57, the average annual streamflow 

for Corney Bayou near Lillie (USGS site number 07366000) was 

475 ft3/s (USGS, 2018). During 1941–71, the average annual 

streamflow for Middle Fork Bayou D’Arbonne near Bernice (USGS 

site number 07365500), located on the parish’s southwestern border 

with Lincoln Parish, was 215 ft3/s (USGS, 2018).

Lower Ouachita-Bayou De Loutre Subbasin 

The Lower Ouachita-Bayou De Loutre subbasin is present in 

the northeastern half of Union Parish. The Ouachita River is the 

primary stream draining the Lower Ouachita-Bayou De Loutre 

subbasin in Union Parish. The Ouachita River enters Louisiana 

from Arkansas, establishing the border between Union Parish 

and Morehouse Parish, flowing in a southerly direction along the 

entirety of Union Parish’s eastern boundary. The average streamflow 

during 1956–77 was 185 ft3/s at Bayou de Loutre near Laran (USGS 

site number 07364700; fig. 1). During this same period, the highest 

monthly average streamflow was 342 ft3/s in April and the lowest 

was 38 ft3/s during August (USGS, 2018). 

Table 4. Summary of selected water-quality characteristics for samples from the Corney Bayou near Lillie and Bayou de Loutre near 

Laran, Louisiana (U.S. Geological Survey, 2018).

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

μg/L, micrograms per liter; NA, not applicable; SMCL, Secondary Maximum Contaminant Level established by the U.S. Environmental Protection Agency 

(2016)]

Temperature 

(°C)

Color 

(platinum 

cobalt 

units)

Specific 

conductance, field

(μS/cm at 

25 °C)

Dissolved 

oxygen

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, 

in μg/L 

(as Fe)

Manganese, 

filtered,

in μg/L

(as Mn)

Dissolved 

solids, 

filtered

Corney Bayou near Lillie (1943–84)1

Median 17.5 15 402 7.9 5.6 81 19 4 45 140 5 195 1,520 283

10th percentile 7.5 0 169 3.9 4.7 34 8 1.9 18 50 2 145 344 109

90th percentile 28 40 557 10.6 6.2 380 27 6 63 715 10 360 2,920 441

Number of 

samples

101 109 61 19 109 116 60 60 60 116 111 6 4 76

Percentage of 

samples that 

do not exceed 

SMCLs

NA 60 NA NA 7.3 NA NA NA NA 72 100 83 0 96

Bayou de Loutre near Laran (1956–86)2

Median 18.5 20 1,740 7.3 6.5 200 61 11 270 484 30 120 185 878

10th percentile 6.63 15 496 4.74 6 61 17 3.66 80.4 126.4 9.6 80 173 315

90th percentile 28.05 40 4,640 10.8 7.1 580 180 28 761.6 1,528 80.4 398 197 2,266

Number of 

samples

60 61 77 13 77 77 77 77 69 77 77 5 2 49

Percentage of 

samples that 

do not exceed 

SMCLs

NA 28 NA NA 57 NA NA NA NA 23 100 80 0 22

SMCLs NA 15 NA NA 6.5–8.5 NA NA NA NA 250 250 300 50 500

1

U.S. Geological Survey site number 07366000 (see fig. 1).

2

U.S. Geological Survey site number 07364700 (see fig. 1).
Surface-Water Quality

Water samples were collected from Corney Bayou near Lillie 

(USGS site number 07366000) during 1943–84 and Bayou de 

Loutre near Laran (USGS site number 07364700) during 1956–86 

(fig. 1) as part of an ongoing program to monitor the State’s 

surface-water resources. The results for the samples were generally 

within SMCLs for concentrations of sulfate and iron (table 4). The 

pH values for the surface-water samples were outside the SMCL 

range for about 93 percent of the samples for Corney Bayou and 

for 43 percent of the samples from Bayou de Loutre. Manganese 

concentrations exceeded the SMCL of 50 micrograms per liter in 

all samples collected from both streams. Median hardness values 

were within the moderately hard range at Corney Bayou and the 

very hard range at Bayou de Loutre. Median dissolved-oxygen 

concentration values were greater than 7 mg/L at both sites; 5 mg/L 

is considered the minimum value for a diverse population of fresh, 

warmwater biota, including sport fish (Louisiana Department of 

Environmental Quality, 2017). Median values for color were equal 

to the SMCL (15 platinum cobalt units) for samples from Corney 

Bayou and greater than the SMCL for samples from Bayou de 

Loutre. 

References Cited 

Brantly, J.A., Seanor, R.C., and McCoy, K.L., 2002, Louisiana groundwater map no. 13—Hydrogeology and potentiometric surface of the 

Sparta aquifer in northern Louisiana, October 1996: U.S. Geological 

Survey Water-Resources Investigations Report 02–4053, 3 sheets. 

[Also available at https://doi.org/10.3133/wri024053.]

Collier, A.L., 2018, Water withdrawals by source and category in 

Louisiana Parishes, 2014–2015: U.S. Geological Survey data 

release, https://doi.org/10.5066/F78051VM.

Collier, A.L., and Sargent, B.P., 2018, Water use in Louisiana, 2015: 

Louisiana Department of Transportation and Development Water 

Resources Special Report no. 18, 138 p. 

Freiwald, D.A., and Johnson, S.F., 2007, Monitoring of Sparta aquifer 

recovery in southern Arkansas and northern Louisiana, 2003–07: 

U.S. Geological Survey Fact Sheet 2007–3102, 4 p. [Also available 

at https://doi.org/10.3133/fs20073102.]

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, 2017, Environmental 

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

Louisiana Department of Environmental Quality, accessed 

September 10, 2019, at https://www.deq.louisiana.gov/assets/docs/

Water/33v09-201707WaterQuality.pdf.

Louisiana Department of Natural Resources, 2017, Strategic Online 

Natural Resources Information System (SONRIS): Louisiana 

Department of Natural Resources database, accessed June 12, 2017, 

at http://sonris.com/.

McGee, B.D., and Brantly, J.A., 2015, Potentiometric surface, 2012, 

and water-level differences, 2005–12, of the Sparta aquifer in northcentral Louisiana: U.S. Geological Survey Scientific Investigations 

Map 3313, 2 sheets, accessed January 23, 2017, at https://pubs.

er.usgs.gov/publication/sim3313.

Payne, J.N., 1968, Hydrologic significance of the lithofacies of the 

Sparta Sand in Arkansas, Louisiana, Mississippi, and Texas: U.S. 

Geological Survey Professional Paper 569–A, 17 p.

Ryals, G.N., 1984, Regional geohydrology of the northern Louisiana 

salt-dome basin; Part II, Geohydrologic maps of the Tertiary 

aquifers and related confining layers: U.S. Geological Survey 

Water-Resources Investigations Report 83–4135, 6 p., 7 pls. [Also 

available at https://pubs.er.usgs.gov/publication/wri834135.]

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

of the base of freshwater in Louisiana: U.S. Geological Survey 

Water-Resources Investigations Report 86–4314, 1 sheet, accessed 

November 2, 2011, at https://pubs.er.usgs.gov/publication/

wri864314.

Snider, J.L., Calandro, A.J., and Shampine, W.J., 1972, Water resources 

of Union Parish, Louisiana: Department of Conservation, Louisiana 

Geological Survey, and Louisiana Department of Public Works 

Water Resources Bulletin no. 17, 68 p.

U.S. Environmental Protection Agency, 2016, Secondary Drinking 

Water Standards—Guidance for nuisance chemicals, accessed 

April 13, 2016, at https://www.epa.gov/dwstandardsregulations/

secondary-drinking-water-standards-guidance-nuisance-chemicals. 

U.S. Geological Survey [USGS], 2016, U.S. Geological Survey Water 

Resources Cooperative Program—Louisiana Water Use Program, 

accessed November 16, 2016, at https://la.water.usgs.gov/WaterUse/

default.asp.

U.S. Geological Survey [USGS], 2018, USGS water data for the 

Nation: U.S. Geological Survey National Water Information System 

database, accessed September 4, 2018, at https://doi.org/10.5066/

F7P55KJN.

By Angela L. Robinson

For additional information, contact: 

Director, USGS Lower Mississippi-Gulf Water Science Center

3535 S. Sherwood Forest Blvd., Suite 120

Baton Rouge, LA 70816

E-mail: gs-w-lmg_center_director@usgs.gov

Fax: (225) 298–5490

Telephone: (225) 298–5481

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

This fact sheet has been prepared by the USGS, 

in cooperation with the Louisiana Department of 

Transportation and Development (DOTD), as part of 

a program to document water use, availability, and 

quality in the parishes of Louisiana. Information on 

the availability, past and current water use, use trends, 

and water quality from groundwater and surface-water 

sources in the parish is presented here. Previously 

published reports (see References Cited section) and 

data stored in the USGS National Water Information 

System (USGS, 2018) are the primary sources of the 

information presented here. Special thanks are given 

to Doug Taylor, Director, and Zahir “Bo” Bolourchi 

(retired), DOTD Cooperative Program with the USGS.

ISSN 2327-6916 (print) ISSN 2327-6932 (online) https://doi.org/10.3133/fs20203002