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Effects of La Niña ENSO on Groundwater Levels in the ACF. Woody Hicks, Scientist Joseph W. Jones Ecological Research Center. November 18, 2010. Radium Spring near Albany. 2010 Rainfall Deviation from Normal. ACF Basin. Rainfall Cumulative Departure, 1896-2009. NOAA Albany 3 Southeast.
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Effects of La Niña ENSO on Groundwater Levels in the ACF Woody Hicks, Scientist Joseph W. Jones Ecological Research Center November 18, 2010 Radium Spring near Albany
2010 Rainfall Deviation from Normal ACF Basin
Rainfall Cumulative Departure, 1896-2009 NOAA Albany 3 Southeast
Water Balance for the ACF WB = P - ET Long-Term Normal Water Balance, in Inches 2007 La Niña Drought Year
Agricultural Water Use More than 24,000 permits statewide for irrigation Nearly 8,000 in SW Georgia (21-county area) In SW Georgia our agricultural pumping averages 1 billion gallons per day during the 6-month growing season—water source is about 74% groundwater in the ACF Basin
Stream Flow Impacts of Agricultural Use Fall Line Gaining GW Capture - 497 ft3/sec
Groundwater Hydrologic Cycle Neutral ENSO Discharge Recharge Recharge Recovery
Groundwater Hydrologic Cycle La Niña ENSO Long Discharge Limited Recharge
Groundwater Levels on November 18, 1980-2010 Upper Floridan Aquifer Dougherty County La Nina La Nina Current Level
Likely Outcomes • Rainfall amounts during January, February, and March of 2011 • will determine the scale of drought impacts during Summer 2011. • If La Niña ENSO persists through Spring 2011, it is likely that • groundwater level declines will result in intermittent flows in • parts of Spring Creek sub basin by mid Summer. • If La Niña ENSO persists into Winter 2012, groundwater level • declines will occur throughout the lower ACF Basin resulting in • significant stream flow declines and the need for supplemental • releases from federal reservoirs on the Chattahoochee River to • meet target state line flows during Summer 2012. • In addition, a persistent La Niña will result in diminished spring • discharge in the lower Flint River Basin enhancing the possibility • of flow reversals from the river into the Upper Floridan aquifer.