Hydrologic Streamflow Conditions for Georgia, 2007

Home , Flint River (Georgia), Lake Allatoona, Lake Seminole, Peachtree Creek, Satilla River

Lakes and Reservoirs Lake Allatoona 845 Reservoirs in Georgia are multipurpose lakes that provide flood protection, power Top of conservation generation, water supply, navigation, recreation, and fish and wildlife management. 840 Full summer pool 840 feet Reservoirs operate at the highest level possible for all these purposes when water levels are close to the top of conservation or “full pool,” which may vary from summer 835 to winter. Reservoir levels declined with low streamflow conditions during the 2007 water Water level Hydrologic Streamflow Conditions for Georgia, 2007 year, and by August and September some of the major water-supply reservoirs receded 830 towards historic low pool elevations. These reservoirs—most operated by the The U.S. Geologic Survey (USGS) Georgia Water Science U.S. Army Corps of Engineers 825 Carters Full winter pool 823 feet Center (GaWSC) maintains a long-term hydrologic monitoring and the Southern Company— Lake Hartwell had water levels that were Lake 820 network of more than 260 real-time streamflow stations and among the lowest recorded Richard B ONDJFMAMJJAS more than 100 noncontinuous streamflow stations throughout Lake Russell Lake since the impoundments were Allatoona Carters Lake Georgia. This network is operated by the USGS GaWSC in Lake Sidney J Strom Thurmond constructed. Lake Lanier, for Lanier Lake 1,080 cooperation with more than 50 different partners at Federal, example, experienced 12 percent 1,075 State, and local government levels. One of the many benefits of more outflow than inflow West Point Lake data collected from this monitoring network is that it allows for during the 2007 water year 1,070 the analysis of the overall hydrologic condition of streams and (http://lanier.sam.usace. lakes of Georgia. army.mil/ accessed on 1,065 Walter F June 13, 2008). Lake Lanier’s George 1,060 historic low occurred during Reservoir Hydrologic Conditions December 1981, at a pool 1,055 The hydrologic condition of a stream is determined elevation of 1,052.66 feet. By through statistical analysis of data from the current water year the end of September 2007, Lake Seminole 1,050 (Jim Woodruff) ONDJFMAMJJAS (October– September) compared to historical data collected at Lake Lanier was at a pool Lake Lanier’s historic low occurred during 1981, at an altitude of Lake Sidney Lanier long-term streamflow stations. During the 2007 water year, the elevation of 1,058 feet, more than 1,072 approximately 1,051 feet. By the end of September 2007, Lake Lanier 12 feet below full pool. Precipitation deficits and shortages of surface-water supplies Full summer pool 1,071 feet USGS GaWSC made significant efforts to verify and document was at an altitude of 1,058 feet, more than 12 feet below full pool. 1,070 Full winter pool 1,070 feet resulted in emergency water-conservation efforts by both State and local authorities, the numerous historic instantaneous low flows at many of (Photo by Brian E. McCallum, USGS.) similar to those during the drought of 1986. Sustained droughts in Georgia have further 1,068 the streamflow stations and also characterize the streamflow emphasized the necessity for having accurate water-resources information to aid in 1,066 conditions as compared to other historical droughts in Georgia. watershed management, conservation efforts, and reservoir operations. The 2007 water year was an extremely dry year and was Streamflow Data 1,064 classified by the State climatologist as a “severe” to “exceptional” The Annual Data Report (ADR) is a publication of USGS Full pool elevation Lowest observed 1,062 drought with the most extreme conditions occurring in northern data collected at all real-time gaging stations, measurement- pool elevation during Georgia. Current drought conditions started in the spring of 2006. only stations, peak flow stations and water-quality monitoring Reservoir Winter Summer water year 2007 1,060 The 2007 winter season had below normal rainfall and drought stations in the State for a given water year. An electronic map Feet above National Geodetic Vertical Datum of 1929 1,058 conditions continued into the spring, resulting in emergency water interface of the streamflow monitoring network allows users to Apalachicola–Chattahoochee–Flint River Basin ONDJFMAMJJAS ELEVATION, IN FEET ABOVE NATIONAL GEODETIC VERTICAL DATUM OF 1929 GEODETIC VERTICAL DATUM IN FEET ABOVE NATIONAL ELEVATION, conservation efforts by Federal, State and local water authorities. view and access current and historical data with graphics and Lanier Sidney Lanier 1070.0 1,071.0 1,058.84 Lake Seminole 78.0 Historically, droughts in Georgia can last between 2 to 5 years. photographs. The following figures were developed using daily, West Point Lake 628.0 635.0 623.36 Streamflow data from the 2007 water year indicates this is monthly, and yearly statistics from the 2007 GaWSC ADR. Walter F. George Reservoir 188.0 190.0 184.90 77.5 one of the worst droughts on record as compared to previous Electronic ADRs from 1999 –2007 can be viewed online at Lake Seminole 77.5 77.5 75.78 77.0 drought periods of 1950 –1957, 1985 –1989, 1999 –2002. http://ga.water.usgs.gov/pubswdr.html Alabama–Coosa–Tallapoosa River Basin Allatoona Lake 823.0 840.0 822.92 76.5 Carters Lake 1072.0 1,074.0 1,051.80 76.0 Savannah River Basin Hartwell Lake 656.0 660.0 651.66 75.5 New Historic Minimums A. B. EXPLANATION Richard B. Russell Lake 475.0 475.0 472.63 Percent of normal 75.0 North Georgia received less precipitation J. Strom Thurmond Lake 326.0 330.0 320.30 OND JFMAMJJAS 2006 2007 than 75 percent of normal 75 percent and greater precipitation (30-year average). 50 to 75 percent 25 to 50 percent References by Andrew E. Knaak and John K. Joiner (A) New record low monthly New monthly minimum Precipitation maps modified from National Oceanic and Atmospheric Administration, accessed streamflows occurred at 80 of Design and layout by Bonnie J. Turcott on June 2, 2008, at http://water.weather.gov/index.php?layer%5B%5D=0&layer%5B%5D= 101 stations with 20 or more New 7-day-average and Caryl J. Wipperfurth minimum 1&layer%5B%5D=3&layer%5B%5D=4&timetype=YM&loctype=STATE&units=engl&timeframe= years of record. current&timeYYYY=2007&timeMM=13&timeDD=1&product=per_normal&loc=stateGA For more information contact: Seven-day-hydrograph data from U.S. Geological Survey, accessed on August 1, 2008, at Director, USGS Georgia Water Science Center (B) New record low 7-day- http://water.usgs.gov/waterwatch/?m=sitedur&r=ga&w=pa07d_dry%2Cmap 3039 Amwiler Road, Suite 130 average streamflows occurred Hydrologic drought map from U.S. Geological Survey, accessed on September 27, 2007, at Atlanta, Georgia 30360 at 21 of 101 stations with 20 or http://water.usgs.gov/waterwatch/?m=dryw&r=ga 770-903-9100 more years of record. Runoff data from U.S. Geological Survey, accessed on August 1, 2008, at http://water.usgs.gov/waterwatch/?m=statesum&r=ga&w=statesum%2Cmedian Or visit the following Web sites: Reservoir data from U.S. Army Corps of Engineers, accessed on June 13, 2008, at http;//ga.water.usgs.gov and http://water.sam.usace.army.mil/ http://www.usgs.gov U.S. Department of the Interior Fact Sheet 2008–3099 U.S. Geological Survey December 2008 Peachtree CreekatAtlanta Flint RivernearNewton Rainfall recordedatthegagingstationwasabout20incheslessthanaverageannualrainfallfor historic lowdailydischargewasrecordedinAugust,andrunoffabouthalfoftheannualaverage. not bringenoughrelieftoovercomeseveralmonthsof“muchbelownormal”streamflow. Anew less thanaverage annualrainfallforthewatershed. (PhotobyBrianE.McCallum, USGS.) was abouthalfof theannualaverage.Rainfallrecorded atthegagingstationwas about15inches September 2007.Newhistoriclow dailydischargewasrecordedinMay andAugust,runoff the ApalachicolaRiver. “Muchbelownormal”streamflowwasobservedfrom March2007to The FlintRiverjoinstheChattahoochee RiveratLakeSeminoleinsouthwestern Georgiatoform watershed. (PhotobyChristopherA.Smith,USGS.) graph Peachtree Creekishighlyurbanizedwith30percentimperviousarea.The dailydischargehydro DAILY DISCHARGE, SEVEN-DAY AVERAGE DISCHARGE, DAILY DISCHARGE, SEVEN-DAY AVERAGE DISCHARGE, IN CUBIC FEET PER SECOND IN CUBIC FEET PER SECOND

IN CUBIC FEET PER SECOND 100,000 IN CUBIC FEET PER SECOND 100,000 10,000 10,000 10,000 10,000 1,000 1,000 s 1,000 1,000 100 100 hows highpeakdischargesduringstormeventsduetourbanization.Summershowersdid 100 100 10 10 1 1 D N O D N O 50 yearsofrecord 62 yearsofrecord 2006 2006 S A J J M A M F J S A J J M A M F J 2007 2007 from 1955to2007. one-half oftheaveragemedians years. Themedianrunofffor2007 was average isshownforseveraldrought gages inGeorgia.Themedianrunoff 2007 wascomputedfrom167streamflow area, orstreamflowyield.Runofffor Runoff isaveragestreamflowperunit Runoff record, incubicfeetpersecond. median streamflowfortheentireperiodof flow ascomparedtohistoricalminimumand Hydrographs shows2007dailymeanstream- Hydrographs: DailyDischarge Hydrographs: Seven-DayAverage Discharge “much belownormal.” from “muchabovenormal”to Data arecategorizedinranges to historical7-dayaverages. average for2007ascompared Hydrographs showthe7-day Ch att ah oo 060MILES 60KILOMETERS 30 30 0 0 c h e e River

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r e Hydrologic DroughtMap— Historical dailyflow

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9518 0020 2007 2002 2000 1988 1955 i EXPLANATION the contextofallhistoricaldata. v

e September 20–26,2007 r streamfow conditions 2007 dailymean Only stationshavingatleast Seven-day average 30 yearsofrecordareused. (http://water.usgs.gov/ DROUGHT WATER YEAR waterwatch/) 7-dayaverage New minimum 2007

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EXPLANATION D N O D N O 50 years of record 50 years of record 2006 2006 1955–2007 Average S A J J M A M F J S A J J M A M F J

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than averageannual rainfallforthewatershed.(Photo byGregoryB.Donley, USGS.) lower thantheannual average.Rainfallrecorded atthegagingstationwasabout 10inchesless was recorded in November, December, January, April, and May, and runoff was about 90 percent streamflow wasobservedfromOctober 2006toAugust2007.Newhistoric lowdailydischarge The SatillaRiverislocatedinthe southeasterncoastalplainofGeorgia. “Muchbelownormal” Satilla RivernearWaycross Chattahoochee RivernearCornelia annual rainfallforthewatershed.(PhotobyChristopherA.Smith,USGS.) annual average.Rainfallrecordedatthegagingstationwasabout28incheslessthanaverage daily dischargewasrecordedinAugustandSeptember, andrunoffwasabouttwo-thirdsofthe below normal”streamflowwasobservedfromMarch2007toSeptember 2007.Newhistoriclow The ChattahoocheeRiveristheprimaryinflowforLakeSydneyLanierinNorth Georgia.“Much

DAILY DISCHARGE, SEVEN-DAY AVERAGE DISCHARGE, DAILY DISCHARGE, SEVEN-DAY AVERAGE DISCHARGE, IN CUBIC FEET PER SECOND IN CUBIC FEET PER SECOND IN CUBIC FEET PER SECOND IN CUBIC FEET PER SECOND 100,000 100,000 10,000 10,000 10,000 10,000 1,000 1,000 1,000 1,000 100 100 100 100 10 10 10 10 1 1 D N O D N O data are 51 yearsofrecord missing where Blank 2006 2006 71 yearsofrecord S A J J M A M F J S A J J M A M F J 2007 2007