Extreme to Extreme : Summary of Hydrologic Conditions in , 2009 The United States Geological Survey (USGS) Georgia Water Science Center

(WSC) maintains a long-term hydrologic Tree Tree monitoring network of more than 317 real- time streamgages, more than 180 ground- water wells of which 31 are real-time, and 10 lake-level monitoring stations. One of the many benefits of data collected from Sign Sign this monitoring network is that analysis of the data provides an overview of the hydrologic conditions of rivers, creeks, , and aquifers in Georgia. reached an all-time historic low elevation of 1,050.79 feet on December 26, 2007, nearly 21 feet Hydrologic conditions are determined below full pool. From December 2008 through September 2009 the lake elevation increased more than 18 feet after Georgia received above normal precipitation and experienced two historic events. Photos by USGS. by statistical analysis of data collected during the current water year1 (WY) and comparison of the results to historical data management and conservation of Georgia’s Streamflow And Groundwater Data collected at long-term stations. During the water resources for the protection of life. 2009 WY Georgia experienced a dramatic On June 10, 2009, Governor Perdue Daily, monthly, and yearly streamflow change from drought conditions to above- met with the State Drought Response and groundwater statistics from the 2009 normal streamflows. MapsA–D indicate Committee and announced that the USGS Annual Data Report (ADR; U.S. that during the first half of the 2009 WY, Environ­mental Protection Division issued Geological Survey, 2010a) were used to most streams in Georgia had flows much a non-drought schedule for outdoor water develop this summary. The ADRs for below normal, but by the end of the year, use for the first time since June 2006 (State WYs 1999–2009 can be accessed online the majority of streams had flows much of Georgia, 2010). This announcement was at http://ga.water.usgs.gov/publications/ above normal. At the start of the 2009 WY, made as a result of substantial rainfalls and pubswdr.html. A digital map is available new historic minimum streamflows were improved water supplies in Georgia. Under at this site to interface with current and recorded at several streamgages with 20 a non-drought schedule, household outdoor historical data, graphics, and photographs or more years of record, and reservoirs water use is allowed 3 days a week. from the Georgia WSC monitoring network. approached historic low elevations. South Georgia received drought relief as a result of historic flooding from March 27–April 3, Quarterly Hydrologic Conditions in Georgia for 2009, Based on 7-Day Average Streamflows 2009. experienced historic flooding during September 16–22, 2009. A. Oct. 1, 2008 B. Mar. 1, 2009 C. June 1, 2009 D. Sept. 30, 2009 During these flood events, Georgia WSC hydrographers verified peak streamflows and flood levels, and this information was shared with Federal, State, and local GEORGIA agencies for use in protecting life and property. New record peak flows were observed in many creeks and rivers through- out the State during these epic floods, and and lake elevations approached full pool. Extreme hydrologic conditions, These maps represent hydrologic conditions in EXPLANATION the context of available historical data. The colors both drought and floods, in the 2009 WY Percentile classes represent current 7-day average streamflow as Much above normal, > 90 emphasizes the need for accurate, timely a percentile class of long-term averages. Only Above normal, 76 to 90 data to help make informed decisions by stations having at least 30 years of record were Normal, 25 to 75 state and local authorities regarding the used (U.S. Geological Survey, 2010b). Because of Below normal, 10 to 24 persistent drought conditions that began in spring Much below normal < 10 2006, streamflow conditions at the beginning of the 1Water year is the period October 1 through 2009 WY in the State were “much below normal” “below normal” to “above normal” (map B, C). September 30 and is designated by the year in (map A). Steady rainfall and spring flooding in south By September 30, 2009, the end of the water year, which it ends. For example, the 2009 water year Georgia brought much-needed relief, and 7-day the 7-day average streamflows throughout most of began on October 1, 2008, and ended on average streamflow conditions improved from Georgia were “much above normal” (map D). September 30, 2009.

U.S. Department of the Interior Printed on recycled paper Fact Sheet 2010–3101 U.S. Geological Survey October 2010 02398000 at Summerville, Georgia Chattooga River at Summerville 02398000 Daily Discharge and 7-Day Average 100,000 Streamfow Conditions, 2009 Water Year

10,000

R a 1,000 g o to t a 100 h C 02398000 10 EXPLANATION in cubic feet per second 7-day average discharge, 02213000 Streamgage 1 100,000 and number PIEDMONT S Savannah–Ogeechee a Chattooga River at Summerville, va n 10,000 Coosa–Tallapoosa–TennesseeAtlanta n 02337000 a Georgia. Photo by USGS. h Jackson R r i 1,000 e Lake v v e i r

R 100 The Chattooga River flows Ocmulgee–Altamaha

Daily discharge, O 10 c 02213000 Oconee– o in the northwest corner of n

in cubic feet per second e e Og Georgia into and 1 ee O N D J F M A M J J A S ch e 2008 2009 e is an inflow to Wiess Lake R R iv i e v r e in Alabama (U.S. Geological e r e Oc h m c COASTAL u PLAIN Survey, 1975). At the beginning o l o g Alt h e r am a e e a of the 2009 WY, the 7-day t iv h t a R a Ri

h v er average streamflow was “much below normal,” and near-historic minimum C n a Satilla–Suwannee– e daily values were observed. In December 2008, 7-day average streamflow c O r St Marys–Ochlockonee e c v i conditions changed from “much below normal” to “normal.” During the Chattahoochee–Flinti t R n R t a e l n t i e l September 2009 flood in northern Georgia, streamflow conditions were h A F c o “much above normal,” and the annual peak flow exceeded the 2-percent co la

h t

i 02318500 annual exceedance probability (50-year recurrence interval). W N 0 30 60 MILES

0 30 60 KILOMETERS Base modified from U.S. Geological Survey 1:2,000,000-scale digital data

Ocmulgee River at Macon 02213000 02213000 at Macon, Georgia 7-Day Average Discharge 100,000 Hydrographs show the 7-day averages for 2009 as compared to historical 7-day averages. Data are

10,000 categorized in percentile ranges from “much above normal” (greater than the 90th percentile) to “much

1,000 below normal” (less than the 10th percentile; U.S. Geological Survey, 2009b). in cubic feet per second 7-day average discharge, 100 EXPLANATION 100,000 Historical (percentile) Ocmulgee River at Macon, Georgia. Much above normal, ≥ 90 Photo by USGS. Above normal, 76 to 89 10,000 Normal, 25 to 75 Below normal, 11 to 24 Much below normal ≤ 10 The Ocmulgee River flows 1,000 2009 water year out of and joins Daily discharge, Daily Discharge in cubic feet per second the to form the 100 O N D J F M A M J J A S Hydrographs show 2009 daily-mean streamflow, in cubic (U.S. Geological 2008 2009 Survey, 1975). In 2009, new feet per second, as compared to historical maximum, record daily low streamflows median, and minimum streamflow for the entire period were observed for the month of record (U.S. Geological Survey, 2009a). of February. During the historic floods in March–April and September 2009, EXPLANATION however, record high streamflows were observed when 7-day average Historical daily flow streamflows were “much above normal” and daily streamflows were near Maximum Median record maximum. Minimum 2009 daily mean

2 02337040 Sweetwater Creek Below Austell, Georgia Climate Response Network Sweetwater Creek near Austell 02337000 The USGS maintains a network of ground- 10,000 water wells to monitor the effects of and other climate variability on groundwater levels. 1,000 R These wells are part of the Climate Response a g o o t Network, which is designed to measure the effects t a 100 h C 02398000 of climate on groundwater levels in unconfined 10 aquifers or near-surface confined aquifers where in cubic feet per second

7-day average discharge, pumping or other human influences on groundwater­ 1 100,000 levels are minimal (U.S. Geological Survey, 2007, PIEDMONT S Savannah–Ogeechee a va n 2009a). The national network consists of about Coosa–Tallapoosa–TennesseeAtlanta n Sweetwater Creek near Austell, Georgia. 02337000 a 10,000 h Jackson R Photo by USGS. 130 wells, of which 15 are located in Georgia. r i e Lake v v e 1,000 i r Information obtained for the 2009 WY from four

R

Ocmulgee–Altamaha of these wells is summarized in this section. These Sweetwater Creek is a major 100 O c wells are monitored as part of the USGS Ground- 02213000 Oconee– o Daily discharge, 10 n tributary of the Chattahoochee e e O water Resources and Cooperative Water Programs. g in cubic feet per second ee River (U.S. Geological Survey, ch 1 e O N D J F M A M J J A S Current conditions of groundwater­ wells in the e 1975). For most of the 2009 WY, R R 2008 2009 iv i e v Climate Response Network can be accessed online r e e r 7-day average streamflow e Oc h m at http://groundwaterwatch.usgs.gov. c COASTAL u PLAIN o fluctuated between “much below l o g Alt h e r am a e e a t iv h normal” and “normal” conditions. New record daily low streamflows were t a R a Ri h v Groundwater Watch er

C n observed for the month of February. During the September 2009 flood, a new a Climate Response Network Satilla–Suwannee– e c annual peak flow for the period of record was recorded on Sweetwater Creek. O r St Marys–Ochlockonee e c v i Chattahoochee–Flinti t This peak flow exceeded the 0.2-percent annual exceedance probability R n R t a e l n t i e l h (500-year recurrence interval). During the peak of this historic flood, the A F c o co Interstate 20 bridge crossing over Sweetwater Creek 300 feet downstream la

h t

i 02318500 W from the USGS streamgage was inundated and closed to traffic. N Well_07H003_Miller 0 30 60 MILES Well 07H003 0 30 60 KILOMETERS –5 Base modified from U.S. Geological Survey is in Miller 0 1:2,000,000-scale digital data County in southwestern 5 10 02318500 Withlacoochee River at US 84, near Quitman, Georgia Georgia and 15 Withlacoochee River at US 84 near Quitman 02318500 is completed in the surficial 20 100,000 25 aquifer. The and below land surface, in feet 10,000 Daily mean water level above (–) water level 20,000 0 2 1,000 in this well 07H003 16,000 4 100 generally rises 12,000 6 rapidly during 8 10 8,000 10 in cubic feet per second wet periods 7-day average discharge, 02357000 12 1 and declines 4,000

100,000 Daily mean discharge, 14 Daily mean water level in cubic feet per second

slowly during below land surface, in feet 2,000 16 10,000 dry periods. 10 1,000 The water 02357000 Withlacoochee River at U.S. 84 near 8 6 Quitman, Georgia. Photo by USGS. 100 level in well 07H003 4 in inches Daily discharge, 10 2 responds Precipitation, The Withlacoochee River flows in in cubic feet per second 0 1 to seasonal O N D J F M A M J J A S the basin in the O N D J F M A M J J A S 2008 2009 2008 2009 change southern coastal plain of Georgia similarly to streamflow at the nearby streamgage on (U.S. Geological Survey, 1975). For Spring Creek near Iron City (02357000), which indicates most of the 2009 WY, 7-day average atmospheric, surface-water, and groundwater streamflow conditions were “normal.” The March–April 2009 flood produced interactions. During the March–April 2009 flood, the a record high 7-day average streamflow, and the highest annual peak flow streamgage on Spring Creek recorded the second at this site since 1948. During the flood peak, the water surface was flowing highest peak flow in 65 years of record (18,500 cubic 5 to 6 feet above U.S. Highway 84 when USGS field crews measured the feet per second, ft3/s) at this site, and water levels in streamflow by boat. well 07H003 increased above the historic median and remained there for the remainder of the 2009 WY.

3 Well_16MM03_White Georgia’s Climate Response Network Well 16MM03 is in White 0 Hydrographs are presented on the Climate Response County in northeastern Georgia 1 Network Web site for wells with at least 5 years of continuous and is completed in the 2 3 data. The 2009 WY data are shown here for selected wells. crystalline-rock aquifer. Water 4 is stored in the regolith and 5 16MM03 fractures, and the water level 6 Daily mean water level 02330450 EXPLANATION is affected by precipitation and below land surface, in feet 7 Helen 02331000 07H003 Monitoring well evapotranspiration (Cressler 1,200 0 and identifier and others, 1983). Precipitation 02198980 1,000 1 Streamgage 02330450 can cause a rapid water-level 800 2 and number rise in wells tapping aquifers 600 16MM03 3 Sa va n overlain by thin regolith (Peck n 4 a 400 r h e R and others, 2009). The water v i 200 5 i v Daily mean discharge, Daily mean water level e in cubic feet per second R r level in well 16MM03 responds O below land surface, in feet O c 0 6 c o m n e to seasonal change similarly u e l 16 g R e i to streamflow at the nearby e v O e g 02331000 e 12 R r ec i h v e streamgage Chattahoochee e e 8 r 02223500 R River at Helen (02330450), which

iv in inches Dublin e 4 21T001 r indicates atmospheric, surface- Precipitation, e 0 e 02198980 h O N D J F M A M J J A S c water, and groundwater o 35P094P 2008 2009 o Altam e a a h ha c interactions. The water level a oc t r k t e v C a i 02203559 r in well 16MM03 rarely rose above the historic daily median during n h R McIntosh a

C t e n R c i the 2009 WY. The highest water level below land surface occurred l i v O F e S r p r in September 2009 when the area received more than 12 inches of in g 07H003 C precipitation during the month, most of which occurred near the end r c i t n a of September and contributed to the flooding. 02357000 l t

Iron City A EXPLANATION EXPLANATION N Daily mean Daily mean water level 0 30 60 MILES Stream discharge Range of historical daily minimum and maximum 0 30 60 KILOMETERS Groundwater level Historical median Base modified from U.S. Geological Survey 1:2,000,000-scale digital data 2009 groundwater level Well_21T001_Laurens Well_35P094_Chatham Well 21T001 is in Laurens Well 35P094 is in County in east-central 22 Chatham County 0 Georgia and is completed 26 in southeastern 2 4 in a semiconfined part of 30 Georgia and is the Upper Floridan aquifer. completed in the 6 34 Water levels in semiconfined surficial aquifer. 8 38 parts of the aquifer fluctuate Water levels in this 10 Daily mean water level Daily mean water level below land surface, in feet seasonally in response to 40 well generally rise below land surface, in feet 12 variations in precipitation, 50,000 0 rapidly during wet 250 0 evapotranspiration, and 5 periods and decline 1 40,000 10 200 02203559 35P094 2 natural drainage or discharge 15 slowly during dry 3 (Peck and others, 2009). The 30,000 20 periods. The water 150 4 02223500 25 water level in well 21T001 20,000 21T001 level in well 35P094 100 30 5 6 responds to seasonal change 10,000 35 responds to seasonal 50 Daily mean discharge, Daily mean water level Daily mean discharge, 40 7 Daily mean water level in cubic feet per second similarly to streamflow at change similarly to in cubic feet per second below land surface, in feet 0 45 8 below land surface, in feet the nearby streamgage on streamflow at the 0 6 12 Oconee River near Dublin 5 02223500 nearby streamgage 10 02198980 (02223500), which indicates 4 on Peacock Creek at 8 3 6 atmospheric, surface- 2 McIntosh (02203559),

in inches 4 in inches

Precipitation, 1 water, and groundwater which indicates Precipitation, 2 0 0 interactions. At the beginning O N D J F M A M J J A S atmospheric, O N D J F M A M J J A S 2008 2009 2009 of WY 2009, water levels in well 21T001 were well below the historic surface-water, and groundwater 2008interactions. During the daily median. During the March–April 2009 flood, the streamgage on March–April 2009 flood, the Peacock Creek streamgage the Oconee River recorded the second highest peak flow in 10 years recorded the highest peak flow at this site for the 2009 WY (46,400 ft3/s), and water levels in well 21T001 increased above the (210 ft3/s), and water levels in well 35P094 increased above historic median and remained there until June 2009 before dipping the historic median and remained there for the remainder of below the historic daily median for the remainder of the water year. the 2009 WY.

4 Lakes and Reservoirs Alatoona Lake Major lakes and reservoirs 180,000 855 160,000 660 throughout Georgia are managed Top of 160,000 primarily by the U.S. Army Corps conservation 850 140,000 pool of Engineers and 140,000 Water 655 level 120,000 Company to provide water for 845 120,000 public and industrial use, flood 100,000 650 protection, power generation, 100,000 840 wildlife management, and Inflow 80,000 80,000 835 recreation. Managing lakes and Outflow 645 60,000 reservoirs requires computer models 60,000 830 that predict changes in climate and 40,000 40,000 Geodetic Vertical Datum of 1929 Geodetic Vertical 640 Datum of 1929 Geodetic Vertical water demands and rely on USGS 825 20,000 Inflow and outflow, in cubic feet per second Inflow and outflow, 20,000 Water level elevation, in feet above National Water Inflow and outflow, in cubic feet per second Inflow and outflow, data. During the first half of the level elevation, in feet above National Water

2009 WY, lakes and reservoirs in 0 820 0 635 O N D J F M A M J J A S Georgia continued to have record O N D J F M A M J J A S 2008 2009 2008 2009 minimum levels as a result of the lengthy drought that began in 2006. Lake 120,000 1,072 Emergency water-conservation efforts by both State and local authorities 1,070 T a 100,000 1,068 ga were in place at the beginning of the lo ah R o Hartwell Lake tow R 1,066 2009 WY. After an extremely wet E Richard B Lake Russell Lake 80,000 spring, however, State climatologists Allatoona Sidney 1,064 R J Strom Lake e declared an end to the drought and the he Lanier Thurmond 1,062 oc ho Lake entire State returned to a non-drought a 60,000 tt a Lake 1,060 h outdoor watering schedule in June C Sinclair Sa va 1,058 n 2009 as lake and reservoir elevations n 40,000 a h West 1,056 approached R i v

Point Datum of 1929 Geodetic Vertical e full pool. Lake r 20,000 1,054 Inflow and outflow, in cubic feet per second Inflow and outflow, Lake Sidney Lanier (Lake 1,052 level elevation, in feet above National Water

Lanier) on the Savannah 0 1,050 is the primary drinking-water source O N D J F M A M J J A S Walter F 2008 2009 for the Atlanta metropolitan area. n George a e Lake Lanier is the most upstream Lake c O 400,000 640 c i reservoir in a series of reservoirs that t n

a l include West Point Lake, Walter F. t 350,000 A 638 George Lake, and . Lake Seminole Lake Lanier had 80 percent more (Jim Woodruff) 300,000 636 inflow than outflow during the 2009 250,000 WY, and lake elevation increased more than 18 feet from December 2008 Hartwell Lake is on the 200,000 634 through September 2009. Flooding in the between Georgia and South Carolina 150,000 watershed in September 2009 contributed on the Savannah and Tugaloo Rivers. 632 a large amount of inflow—50 percent Hartwell is the most upstream reservoir 100,000 Geodetic Vertical Datum of 1929 Geodetic Vertical more than in June, July, and August on the . Water is released 630 50,000 Inflow and outflow, in cubic feet per second Inflow and outflow, combined, and the lake elevation increased to the downstream reservoirs, Richard level elevation, in feet above National Water 4.5 feet from September 19 to September 30. B. Russell and J. Strom Thurmond. 0 628 Approximately 150 river miles down- These three lakes on the Savannah River O N D J F M A M J J A S stream, the elevation of West Point Lake are managed by the U.S. Army Corps 2008 2009 also increased 4 feet during the September of Engineers for water supply, power (Data from U.S. Army Corps of Engineers, 2009a) floods, but released discharge was nearly generation, and water-quality needs of Allatoona Lake is on the equal to the inflow, which resulted in the the Savannah River from below Thurmond and is managed by the U.S. Army Corps of lake elevation being maintained at pre- Dam all the way to Savannah, Georgia, and Engineers. During the 2009 WY, Allatoona flood levels. The volume of Lake Lanier is the Atlantic Ocean (U.S. Army Corps of Lake had 20 percent more inflow than out- nearly 14 times greater than the volume of Engineers, 2009c). On December 9, 2008, flow, and lake elevation increased more West Point Lake, which remains near full Hartwell Lake reached an all-time historic than 27.5 feet from December 2008 through pool elevation even in times of drought. low elevation of 637.49 feet. Shortly September 2009. The September 2009 flooding West Point Dam provides flood protection thereafter, however, lake elevation began in the watershed contributed a large amount of and hydroelectric power to Troup County, to rise (from December 2008 through inflow. Nearly 50 percent more inflow occurred and construction was authorized by the June 2009), and Hartwell Lake had nearly in September than in May, June, July, and Act of 1962 (U.S. Army 2.6 times more inflow than outflow; lake August combined, and lake elevation increased Corps of Engineers, 2009b). elevation increased more than 20 feet. 13 feet from September 19 to September 30.

5 Flooding in South Georgia, Flooding in North Georgia, September 2009 March–April 2009 Flooding in South Georgia during Flooding in North Georgia occurred over March–April 2009 resulted in the highest several days, during September 18–22, 2009, 85° 84°30' 84° streamflows recorded since 1948 on several as a result of precipitation totals that were rivers and since 1929 on a few others. Rainfall as high as 20 inches in some areas. Georgia totals ranged from 5.6 to 14.0 inches during the WSC field crews were mobilized and made 6-day event across southern Georgia (National 118 discharge measurements before, during, and Weather Service, 2010a). Seven USGS field after (September 16–30, 2009) the flood. These 34° crews worked extensively for 10 days and measurements were made in a timely manner made 84 flood measurements in south Georgia. sometimes during perilous peak-flow or close to These measurements were used to extend peak-flow conditions and were used to extend or or verify the highest streamflow ratings. verify streamflow ratings. Although 20 USGS Atlanta Six streamgages in the flooded area had peak streamgages throughout the northern part of

streamflows that exceeded the 1-percent annual the State were destroyed during the flood, all 33°30' exceedance probability (100-year recurrence were restored to active status within 5 days. At interval). The Federal Emergency Management several streamgages, temporary instrumentation Agency declared 46 counties in Georgia as was installed hundreds of feet away from the disaster areas as a result of the flooding (U.S. main channel. Peak flows that exceeded the Base modified from 0 15 30 MILES Geological Survey, 2009b). 0.2-percent annual exceedance probability U.S. Geological Survey (500-year recurrence interval) were recorded 1:2,000,000-scale digital files 0 15 30 KILOMETERS March 27, 2009 March 28, 2009 March 29, 2009 at 15 streamgages throughout the flooded area (U.S. Geological Survey, 2010c). EXPLANATION GEORGIA The Federal Emergency Management Precipitation—September 18–22, 2009, Agency reported that nearly $220 million in flood in inches damage claims were submitted as a result of this 0 to 2 10 to 12 April 1, 2009 April 2, 2009 April 3, 2009 flood event, and 14 counties declared Federal 2 to 4 12 to 14 disaster areas (The Atlanta Journal-Constitution, 4 to 6 14 to 16 6 to 8 16 to 18 2009). Eleven fatalities were attributed to this 8 to 10 18 to 20 flood, many of which occurred during early morning hours when drivers attempted to cross Flood discharge—Measurement made between September 16–30, 2009 EXPLANATION flooded roads. Significant damage to hundreds Real-time streamgage Observed daily precipitation, in inches of roads and bridges across the region severely 5.0 2.0 0.50 Crest-stage streamgage 10 4.0 1.5 0.25 affected traffic conditions for months after the 8.0 3.0 1.0 0.10 6.0 2.5 0.75 0.01 event (National Weather Service, 2010b). 5.0 2.0 0.50

References Cressler, C.W., Thurmond, C.J., and Hester, W.G., September 25, 2009, accessed March 15, 2010, U.S. Geological Survey, 2009b, Historic Flooding 1983, Groundwater in the greater Atlanta region, at http://www.ajc.com/news/atlanta/six-more- in South Georgia, March 27–April 3, 2009: Georgia: Georgia Geological Survey Information counties-added-147169.html. U.S. Geological Survey Fact Sheet 2009–3079, Circular 63, 144 p. 2 p., accessed June 1, 2010, at http://pubs.usgs. U.S. Army Corps of Engineers, 2009a, Lake gov/fs/2009/3079/. National Weather Service, 2010a, Advanced Hydro- elevations, inflows and outflows, accessed May logic Prediction Service, precipitation maps for 1, 2010, at http://www.sas.usace.army.mil/. U.S. Geological Survey, 2010a, U.S. Geological Georgia, accessed June 24, 2009, at http://www. Survey annual data report for Georgia, water U.S. Army Corps of Engineers, 2009b, West Point srh.noaa.gov/rfcshare/precip_analysis_new.php. year 2009, accessed May 1, 2010, at http:// Lake: U.S. Army Corps of Engineers, Mobile ga.water.usgs.gov/publications/pubswdr.html. National Weather Service, 2010b, Southeast United District, accessed May 1, 2010 at http://westpt. States floods, September 18–23, 2009: Silver sam.usace.army.mil/. U.S. Geological Survey, 2010b, Water Watch— Current water resources conditions, accessed Spring, MD, U.S. Department of Commerce, U.S. Army Corps of Engineers, 2009c, Hartwell May 1, 2010, at http://waterwatch.usgs.gov. National Oceanic and Atmospheric Administration, Dam & Lake: U.S. Army Corps of Engineers, Service Assessment, accessed March 15, 2010, Savannah District, accessed May 1, 2010 at U.S. Geological Survey, 2010c, Historic Flooding at http://www.nws.noaa.gov/os/assessments/ http://www.sas.usace.army.mil/lakes/hartwell/ in Northern Georgia, September 16–22, pdfs/se_floods10.pdf. intro.htm#funfacts. 2009: U.S. Geological Survey Fact Sheet 2010–3061, 2 p., accessed August 10, 2010, Peck, M.F., Painter, J.A., and Leeth, D.C., 2009, U.S. Geological Survey, 1975, Hydrologic unit at http://pubs.usgs.gov/fs/2010/3061/. Ground-water conditions and studies in Georgia, map 1974, State of Georgia: U.S. Geological 2006–2007: U.S. Geological Survey Scientific Survey, scale 1:500,000, 1 sheet. Investigations Report 2009–5070, 86 p.; By Andrew E. Knaak, Timothy K. Pojunas, and U.S. Geological Survey, 2007, U.S. Geological at http://pubs.usgs.gov/sir/2009/5070/. Michael F. Peck Survey Ground-Water Climate Response State of Georgia, 2010, Governor, EPD Ease Network: U.S. Geological Survey Fact Sheet For more information contact: Out­door Water Use Schedules, accessed 2007–3003, 4 p., accessed July 1, 2009, Director, USGS Georgia Water Science Center May 1, 2010, at http://gov.georgia.gov/00/press/det at http://pubs.usgs.gov/fs/2007/3003/. 3039 Amwiler Road, Suite 130 ail/0,2668,78006749_141938033_143196762,00.html. U.S. Geological Survey, 2009a, U.S. Geological Atlanta, Georgia 30360 The Atlanta Journal-Constitution, 2009, Six more Survey Groundwater Watch, Climate Response 770-903-9100 counties added to federal disaster list: The Network, accessed May 1, 2010, at http://ga.water.usgs.gov/ Atlanta Journal-Constitution Cox Media Group, http://groundwaterwatch.usgs.gov/.

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