An investigation to document groundwater levels and stream base flow in the lower Chattahoochee-Flint and western and central Aucilla-Suwanee-Ochlockonee River basins during low-flow conditions was conducted by the U.S. Geological Survey in November 2008. During most of 2008, moderate to severe drought conditions prevailed throughout southwestern Georgia. Groundwater levels were below median daily levels throughout most of 2008; however, in some wells, groundwater levels rose to median daily levels by November. Discharge in most of the streams in the study area also had risen to median levels by November. The potentiometric surface of the Upper Floridan aquifer was constructed from water-level measurements collected in 21 counties from 376 wells during November 1-10, 2008. The potentiometric surface indicates that groundwater in the study area generally flows to the south and toward streams except in reaches discharging to the Upper Floridan aquifer. The degree of connection between the Upper Floridan aquifer and streams decreases east of the Flint River where the overburden is thicker. Decreased connectivity between ground and surface water is evident from the stream-stage altitudes measured in November 2008 east of the Flint River, which are not similar to water-level altitudes measured in the Upper Floridan aquifer. Stream-stage measurements were collected at 111 sites-26 U.S. Geological Survey streamgaging sites and 85 additional synoptic sites without gages. Streamflow measurements were made at 87 of the sites during November 2008 and were used to estimate base flow. The measurements indicate that stream reaches range from losing up to 10 cubic feet per second to gaining up to 4,559 cubic feet per second; five stream reaches were determined to be losing stream reaches. Of the 11 stream reaches in the Alapaha River subbasin, 7 were dry when measured in November 2008.

The.U.S..Geological.Survey.has.been.working. cooperatively.with.the.Albany.Water,.Gas,.and.Light. Commission.to.monitor.groundwater.quality.and.availability. since.1977..This.report.presents.an.overview.of.groundwater. conditions.and.studies.in.the.Albany.area.of.Dougherty. County,.Georgia,.during.2008..Historical.data.also.are. presented.for.comparison.with.2008.data..Ongoing.monitoring. activities.include.continuous.water-level.recording.in.24.wells. and.periodic.water-level.measurements.in.5.wells..During. 2008,.water.levels.in.10.of.the.continuous-recording.wells. were.below.normal,.corresponding.to.lower.than.average. rainfall..Groundwater.samples.collected.from.25.wells.in. the.Upper.Floridan.aquifer.indicate.that.nitrate.levels.during. 2008.were.similar.to.values.from.2007,.with.a.maximum.of. 12.5.milligrams.per.liter.at.one.well.. Water.samples.collected.from.the.Flint.River.and.wells.. at.the.Albany.well.field.were.analyzed.and.plotted.on.a.trilinear.diagram.to.show.the.percent.composition.of.selected.major. cations.and.anions..Groundwater.constituents.(major.cations. and.anions).of.the.Upper.Floridan.aquifer.at.the.Albany.well. field.remain.distinctly.different.from.those.in.the.water.. of.the.Flint.River. To.improve.the.understanding.of.the.groundwater-flow. system.and.nitrate.movement.in.the.Upper.Floridan.aquifer,. the.U.S..Geological.Survey.is.developing.a.groundwater-flow. model.in.the.Albany.area.of.southwestern.Georgia..The.model. is.being.calibrated.to.simulate.periods.of.dry.(October.1999). hydrologic.conditions..Preliminary.results.of.particle.tracking. indicate.that.water.flows.to.the.well.field.from.the.northwest.

The U.S. Geological Survey, in cooperation with the Albany Water, Gas, and Light Commission has conducted water resources investigations and monitored groundwater conditions and availability in the Albany, Georgia, area since 1977. This report presents an overview of hydrologic conditions, water quality, and groundwater studies in the Albany area of Dougherty County, Georgia, during 2009. Historical

Schematic cross sections showing the hydrologic connection between the Flint River, the overburden sediments of the upper semiconfining unit, and the Upper Floridan aquifer in Georgia during the wet season and the dry, summer growing season .

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