Report: Water levels good for decades
Published 7:36 pm Wednesday, January 19, 2011
Lincoln Countians may lament lengthy periods of little to norain, but the rain the county does receive appears to be enough tolast for a number of years into the future.
Even if it never rained on the county again, the aquifers beneaththe earth could supply water for decades on end without drying up,said Jimmy Baldwin, groundwater management chief with the PearlRiver Basin Development District.
Annual rainfall currently replenishes the water supply at such arate the wells’ level of depletion is among the lowest in SouthwestMississippi, he told county supervisors Tuesday during thedistrict’s annual groundwater report. His report followed testingof Lincoln County wells in December.
“Lincoln County is very fortunate. There’s a lot of water in thiscounty,” Baldwin said. “As long as the population growth doesn’tskyrocket and you don’t have a lot of industry that requires a lotof water, you’ve got several decades of water.”
Of the six wells PRBDD surveyed, the shallowest is depleting theleast. Drilled into an aquifer beneath north Brookhaven in 1979 andtagged as well H0061 by the U.S. Geological Survey, its water levelhas dropped 1.21 feet in about 31 years, an annual loss of about.04 feet per year – the lowest in the county. The 168-foot deepwell leads to 73.21 feet of water, a shallow well that easilyrecharges from local rainfall.
Lincoln Rural Water Association’s Pleasant Ridge well, C0046, isdropping by 0.31 feet per year. Drilled in 1984 at a depth of 563feet, the hole reaches into an aquifer 140.21 feet deep. It hasfallen by 8.21 feet since its first measurement was taken in1997.
The association’s Red Star well, C0072, is falling by 0.37 feet peryear. Drilled in 1984 to a depth of 350 feet, it reaches down to anaquifer that is 178.27 feet deep. It has fallen by almost 5 feetsince the development district fire measured it 13 years ago.
Another north Brookhaven well, H0008, is dropping by 0.57 feet peryear. The second north well was drilled in 1967 to a depth of 462feet, reaching into an aquifer that is 205.23 feet deep. Its waterlevel has dropped 24.23 feet in 42 years.
Topisaw Creek Water Association’s Greenwood Road well, H0077, isfalling by 0.73 feet per year. The 222-foot deep well was drilledin 1988, reaching an aquifer that is 95.05 feet deep. It has fallen5.6 feet since PRBDD first tested it in 2003.
The well in the best standing is not in use. Naturally, the Topisawassociation’s out-of-use well in Ruth, R0029, is falling by only0.02 feet per year. Drilled in 1989 to a depth of 447 feet, thewell accesses an aquifer that is 104.37 feet deep and has remainedaround that depth for the last three years. It has fallen only 0.34feet since 1990.
Lincoln County is served by four water associations – the BogueChitto Water Association, Brookhaven municipal system, and theLincoln Rural Water and Topisaw associations.
The four suppliers operate a total of 24 wells and service 11,200connections. Together they pump about 2.7 million gallons perday.
Baldwin took a moment to explain the science of water management tosupervisors.
Water is supplied to Lincoln County through soil formations thatsoak rainwater into belowground aquifers. Statewide, thesegeological formations slope toward the southwest at a decline of30-40 feet per mile and are overlain by younger formations in thatdirection.
Aquifer outcroppings on the surface recharge directly fromrainfall, but deeper aquifers – confined aquifers in the earth’ssubsurface at depths of 600 feet or more – collect rainwater thatdrains from areas up to 20 miles to the northeast in Copiah andparts of Lawrence and Simpson counties.
The geological formations that collect rainwater for the county’saquifers are the Citronelle Formation, which covers most of LincolnCounty and its neighboring counties to the south; thePascagoula/Hattiesburg Formations, which spread across southMississippi and snake into Lincoln County’s northeastern bordersfrom the southeast and into its northwestern borders from the west;and the Catahoula Formation, which barely touches Lincoln Countybut covers much of Copiah County and recharges deep aquifers.
Collectively, the wells drilled into Lincoln County compose theMiocene Aquifer, a formation that is an estimated 28 million yearsold.