Water Resources of Bienville Parish, Louisiana

Knowing how much water Bienville Parish, in north-central Louisiana, has, how it is used and how good it is helps water managers and residents look after it. This U.S. Geological Survey fact sheet, prepared with the Louisiana Department of Transportation and Development, sums it up.

How the water is used

In 2014 the parish withdrew about 13.03 million gallons a day (Mgal/d): 12.88 Mgal/d of groundwater and 0.15 Mgal/d of surface water.

Agriculture — irrigation and livestock — came to about 0.18 Mgal/d, about 1 percent. Figures are rounded, so they may not add up exactly.

Water withdrawals, 1960–2014. Use was measured every five years from 1960 to 2010 and again in 2014; it peaked in 1995 at more than 17 Mgal/d.

The aquifers

Bienville Parish. Shading shows the approximate altitude of the base of fresh groundwater; the line A–A′ is the section below. From the USGS fact sheet.

The Sparta aquifer is the main source in the east and the Carrizo-Wilcox in the west; the Upland terrace aquifer adds a little, and the Cockfield aquifer lies under a narrow strip in the northwest corner. Fresh groundwater — water with 250 milligrams per litre (mg/L) of chloride or less — reaches down to between about 0 and 500 feet below sea level (the National Geodetic Vertical Datum of 1929, NGVD 29) in the Carrizo-Wilcox, from the western border toward the centre, and to between about 200 and more than 400 feet below it in the Sparta, from the centre toward the east-northeast.

An idealised west-to-east section through the parish; individual sand and clay layers are not shown. Modified from Ryals (1984); base of freshwater from Smoot (1988).

Sparta aquifer

• Extent: a large regional aquifer, holding fresh water under about two-thirds of the parish; very fine to medium sand with lenses of silt and clay, exposed at the surface in the centre of the parish.
• Thickness: from nothing at its western edge, in the centre of the parish, to more than 800 feet in the northeast near Arcadia. Its base runs from more than 150 feet above NGVD 29 in the west to more than 400 feet below it in the east and northeast.
• Flow: recharged by rain soaking in where it is exposed and by leakage from aquifers above; the water moves northeast, toward the big pumping centre at West Monroe in Ouachita Parish, and leaves through wells and leakage.
• Water levels: in 2012, from about 220 feet above NGVD 29 in the southwest to about 40 feet above it in the northeast. At well Bi-144 they fell for decades — steadily, about 48 feet from 1970 to 2009, then sharply, about 10 feet from 2010 to 2012 — but have risen since 2012, reaching about 70 feet above NGVD 29 in 2016.
• Wells (2017): 367 active — 253 domestic, 56 public supply, 33 industrial, 25 irrigation; 30 to 760 feet deep; reported yields 2 to 2,500 gallons a minute.
• Use (2014): 10.18 Mgal/d industry, 1.70 public supply, 0.18 rural domestic, 0.02 livestock.

Carrizo-Wilcox aquifer

The sands and gravels of the Carrizo and Wilcox aquifers are connected and treated as one. It lies under the whole parish but supplies only a small share of its groundwater, because much of its water is salty: fresh in the southwest, salty in the northeast, with the change in the middle.

• Thickness: exposed in the southwest and thickening eastward, from 0 to 1,500 feet, greatest in the southeast; mostly 500 to 1,000 feet thick. Fresh water reaches from 0–99 feet below NGVD 29 in the west to more than 500 feet below it in the centre.
• Flow: recharged by rain in the west; the water moves toward Castor and Woodardville, where heavy pumping has lowered local levels.
• Water levels: at well Bi-214, about 6 miles northwest of Ringgold, little long-term change, typically varying about half a foot a year.
• Wells (2017): 8 active — 6 domestic, 2 public supply; 140 to 335 feet deep; yields 42 to 100 gallons a minute.
• Use (2014): 0.63 Mgal/d public supply, 0.13 rural domestic.

Upland terrace aquifer

Beside the Red River alluvial aquifer, it underlies the western third of the parish, roughly southwest of Kepler Creek Lake. Sands and gravel lie near its base and finer sand and clay near the top; the terrace deposits average about 100 feet thick, recharged by rain.

• Water levels: at well Bi-234, about 2 miles northwest of Woodardville, measured 1980–2016: down about 4 feet from 1987 to 2008, up about 5 feet from 2009 to 2016.
• Wells (2017): 26 active — 19 domestic, 6 irrigation, 1 public supply; 40 to 160 feet deep; yields 25 to 600 gallons a minute.
• Use (2014): about 0.02 Mgal/d rural domestic, under 0.01 livestock.

Water levels in wells Bi-144 (Sparta), Bi-214 (Carrizo-Wilcox) and Bi-234 (Upland terrace), in feet above NGVD 29.

Groundwater quality

The state's long-term monitoring sampled fresh groundwater from 112 Sparta wells (1940–2014) and 59 Carrizo-Wilcox wells (1941–2004), and compared it with the EPA's secondary maximum contaminant levels (SMCLs) — non-enforceable guidelines for taste, colour, staining and similar effects.

Results were generally within the SMCLs for chloride, sulfate, manganese and dissolved solids. pH fell outside the range in more than 60 percent of Sparta samples and about 35 percent of Carrizo-Wilcox samples, and iron exceeded its limit in more than 70 percent of Sparta samples.

Surface water

Surface water flows generally south, through five subbasins. In 2014 about 0.15 Mgal/d was taken from small streams for farming — about 0.12 for irrigation and 0.02 for livestock.

Surface-water quality

Samples from Loggy Bayou near Ninock (1954–81) and Kepler Lake near Castor (1959–74) were generally within the SMCLs for chloride and sulfate.

Five mg/L of dissolved oxygen is considered the minimum for a diverse community of freshwater warm-water life, including sport fish.

Sources

• Robinson, A.L., and White, V.E., 2020, Water resources of Bienville Parish, Louisiana: U.S. Geological Survey Fact Sheet 2020–3052, prepared in cooperation with the Louisiana Department of Transportation and Development. https://pubs.usgs.gov/publication/fs20203052
• The tables, figures and captions come from the fact sheet's PDF, which the web version lacks.
• For Black Lake Bayou and Saline Bayou the fact sheet gives the same figure for the annual average streamflow as for the lowest monthly average (549 and 171 ft³/s); since an average cannot equal the lowest month unless every month is the same, neither is given here.
• Rewritten in hubnx's own words.