Summary of Hydrologic Conditions in Georgia, 2008

The United States Geological and new historic minimum flows were Survey (USGS) Georgia Water Science recorded at several streamgages with Center (WSC) maintains a long-term 20 or more years of record. New historic hydrologic monitoring network of more low water levels were recorded in some than 290 real-time streamgages, more of Georgia’s confined and unconfined than 170 groundwater wells, and 10 lake aquifers, and many recorded water levels and reservoir monitoring stations. One of were below the historic median. Several the many benefits of data collected from lake and reservoir water levels were well this monitoring network is that analysis below average and continued to decline as of the data provides an overview of the the end of the 2008 WY approached. hydrologic conditions of rivers, creeks, Historically, droughts in Georgia Lake Sidney Lanier, Georgia. Photo by Brian E. McCallum, USGS, February 2008. reservoirs, and aquifers in Georgia. typically have lasted between 2 and Hydrologic conditions are determined 5 years. The latest drought began in spring by statistical analysis of data collected 2006. Georgia’s Drought Level One Local governments asked residents to limit during the current water year1 (WY) and through Four are issued by the Georgia showers to 5 minutes or less, reuse clean comparison of the results to historical data Environmental Protection Division household water, and install low-flow collected at long-term stations. During (Regan and Cash, 2009). The drought toilets, faucets, and showerheads, if the drought that persisted through 2008, levels implement water saving techniques possible, in older homes (City of Union the USGS succeeded in verifying and with Level One Drought being the least City, 2008). documenting numerous historic low-flow conservative to Level Four Drought statistics at many streamgages and current being the most conservative. Conditions water levels in aquifers, lakes, and reser- in north Georgia developed from a Level Streamflow and Groundwater Data voirs in Georgia. Streamflow data from One Drought in June 2006, with hourly The illustrations in this Fact Sheet the 2008 WY indicate that this drought limits on outdoor watering schedules, to were created using the daily, monthly, is one of the most severe on record a Level Four Drought in September 2007. and yearly streamflow and groundwater when compared to drought periods of On October 23, 2007, the State of statistics from the 2008 USGS Annual 1950–1957, 1985–1989, and 1999–2002. Georgia mandated a 10-percent reduction Data Report (ADR), (U.S. Geological Precipitation deficits in 2008 or greater in water consumption in all Survey, 2009a). The ADRs for WYs continued from the previous 2 years, areas designated as Level Four Drought. 1999–2008 can be accessed online at Outdoor water use was restricted in http://wdr.water.usgs.gov/adrgmap/index. residential areas. Commercial water html. A digital map is available at this site 1Water year is the period October 1 through September 30 and is designated by the year in which users, such as carwashes, were asked to to interface with current and historical it ends. For example, the 2008 water year began on voluntarily reduce their consumption data, graphics, and photographs from the October 1, 2007, and ended on September 30, 2008. by 10 percent (Regan and Cash, 2009). Georgia WSC monitoring network.

New Minimum Streamflows

(A) New record-low monthly discharge A B EXPLANATION occurred at 75 of 103 streamflow-gaging Percent of normal stations with 20 or more years of record in precipitation 2008. These 75 streamflow stations are located during 2008 throughout Georgia. Most of the State received 90 percent and greater less than normal precipitation. Normal is 75–89 percent defined as a 30-year average for 1971–2000. 50–74 percent Streamgage (B) New record-low 7-day average discharge New monthly minimum occurred at 23 streamgages with 20 or more New 7-day years of record in 2008. More than half of these average minimum streamflow stations, 14 of 23, also had new 7-day average minimum streamflows in the 2007 WY. The majority of these streamflow- gaging stations were located in north Georgia, which received 75–90 percent of normal precipitation during WY 2008.

U.S. Department of the Interior Printed on recycled paper Fact Sheet 2009–3109 U.S. Geological Survey December 2009 02380500 Coosawattee River Near Ellijay, Georgia

Hydrologic Drought Map, Coosawattee River near Ellijay 02380500 7-day average streamfow conditions 10,000 August 8–14, 2008 This map represents hydrologic conditions in the 1,000 context of available historical data. Only stations having at least 30 years of record were used (U.S. Geological

100 Survey, 2009b). EXPLANATION Hydrologic drought, 7-day

in cubic feet per second average percentile 7-day average discharge, Carters 10 Lake Extreme, new low 02380500 1,400 Severe, ≤ 5 Coosawattee River near Ellijay, Moderate, 6 to 9 1,200 Georgia. Photo by USGS. Below normal, 10 to 24 1,000 Normal, ≥ 25 Major river basin 800 The Coosawattee River is the Streamgage 600 02217475 Athens primary inflow for Carters Lake Sa 400 Savannah–Ogeechee va Daily discharge, n in north Georgia. The peak Coosa–Tallapoosa–TennesseeAtlanta n a h flow recorded for the 2008 WY in cubic feet per second 200 PIEDMONT R iv r e at Coosawattee River near e r 0 v O N D J F M A M J J A S i Ellijay was 3,420 cubic feet per R 3 2007 2008 Milledgeville second (ft /s), the 12th lowest Ocmulgee–Altamaha O c o annual peak flow in 68 years Macon n Oconee– e of record. Annual runoff was e Og ee Dublin ch less than one-half of the long-term average. New historic low 7-day average e R e iv R streamflows were observed from October through February, and streamflows e i r v e e e COASTAL O r rarely reached “normal” conditions throughout the year. The peak flow of the h c c PLAIN m year was in August when Tropical Storm Fay brought short-term relief, but o u o l 02225000 g h e Alt a r am conditions quickly returned to “much below normal” because of persistent t e e t Riv ah a a R drought conditions. h 02350512 i ve C r n a e Chattahoochee–Flint c O r e c v i i t R Satilla–Suwannee– n t a n l i St Marys–Ochlockonee t l A F

02350512 Flint River near Oakfield, Georgia Base modified from N U.S. Geological Survey 0 30 60 MILES 1:2,000,000 digital data Flint River near Oakfield 02350512 0 30 60 KILOMETERS

1,000,000 Daily Discharge

100,000 Hydrographs show 2008 daily-mean streamflow, in cubic feet per second, as compared to historical minimum and median streamflow for the entire 10,000 period of record (U.S. Geological Survey, 2009a). EXPLANATION in cubic feet per second 7-day average discharge, 1,000 Historical daily flow 12,000 Minimum Median Flint River near Oakfield, Georgia. 10,000 Photo by USGS. 2008 daily mean 8,000 The Flint River flows from the Piedmont 6,000 7-Day Average Discharge to Lake Seminole in southwest Georgia 4,000 Hydrographs show the 7-day average for 2008 as

(U.S. Geological Survey, 1975). The Daily discharge, 2,000 compared to historical 7-day averages. Data are

Flint River is one of only 40 rivers in in cubic feet per second categorized in percentile ranges from “much the contiguous United States that flow 0 above normal” (greater than the 90th percentile) unimpeded for more than 200 river miles O N D J F M A M J J A S to “much below normal” (less than the (Georgia Humanities Council, 2009). 2007 2008 10th percentile) (U.S. Geological Survey, 2009b).

In 2000, the General Assembly passed House Bill 1362, “Flint River Drought Protection Act” EXPLANATION (Georgia General Assembly, 2000). This Act aims to maintain a minimum flow by providing incentives for farmers in southwest Georgia to not irrigate their land during a severe drought. Historical (percentile) Much above normal, ≥ 90 The peak flow for the 2008 WY was 11,700 ft 3/s, this is the second lowest in 52 years of Above normal, 76 to 89 record. Annual runoff was one-half the long-term average. New historic low 7-day average Normal, 25 to 75 Below normal, 11 to 24 discharge and historic low daily-mean streamflows were observed. Flow was “normal” Much below normal ≤ 10 from January to April and during Tropical Storm Fay in August and September but otherwise was “below normal.” 2008 water year

2 02217475 Middle Oconee River near Arcade, Georgia Climate Response Network Middle Oconee River near Arcade 02217475

10,000 The USGS maintains a network of wells to monitor the effects of droughts and other climate variability on groundwater levels. These wells 1,000 are part of the Climate Response Network, which is designed to reflect the effects of climate on

100 groundwater levels in unconfined aquifersor near- surface confined aquifers where minimal pumping in cubic feet per second 7-day average discharge, or other human influences on groundwater levels 10 occur (U.S. Geological Survey, 2007). The 1,400 national network consists of about 140 wells, and Middle Oconee River near Arcade, Georgia. 1,200 15 of these wells are located in Georgia. Informa- Photo by USGS. 1,000 tion obtained for the 2008 WY from 4 of these 800 The Oconee River, which begins in the wells is summarized in this section. These wells Piedmont, joins the Ocmulgee River to 600 are monitored as part of the USGS Groundwater 400 form the Altamaha River in Georgia’s Daily discharge, Resources and Cooperative Water Programs. Upper Coastal Plain. Several cities are in cubic feet per second 200 Current conditions of groundwater wells in the located along the Oconee River, including 0 Climate Response Network can be accessed online O N D J F M A M J J A S Athens, Milledgeville, and Dublin (U.S. at http://groundwaterwatch.usgs.gov. Geological Survey, 1975). 2007 2008

The peak flow for the 2008 WY was 1,670 ft3/s, this is the lowest annual peak discharge in Groundwater Watch 22 years of record. Annual runoff was one-third of the long-term average. New historic low Climate Response Network 7-day average discharge and historic low daily-mean streamflows were observed from October through December, and streamflow rarely reached normal conditions throughout the year. The annual peak was in August when Tropical Storm Fay brought short-term relief, although conditions quickly returned to “much below normal” because of persistent drought conditions.

Well 07H003 –5 Tropical storm Fay is located in 0 Miller County 5 02225000 Altamaha near Baxley, Georgia in south­ western 10 Altamaha River near Baxley 02225000 Georgia and 15 is completed 20

1,000,000 in the surficial above (–) land surface, in feet

Daily mean water level below and 25 aquifer. The 8,000 0 Blank where water level data are missing 100,000 5 in this well 6,000 generally rises 10 rapidly during 4,000 10,000 wet periods 15 and declines 2,000

in cubic feet per second 20 7-day average discharge, Daily mean discharge,

slowly during in cubic feet per second 1,000 Daily mean water level dry periods. A 0 25 below land surface, in feet 25,000 15 new record- 10 Altamaha River near Baxley, Georgia. 5 20,000 low water in inches 0

Photo by USGS. Precipitation, level was O N D J F M A M J J A S 2007 2008 15,000 recorded on 10 0 December 28, The Altamaha River basin is 10,000 8 5 14,000 square miles (mi2) and drains 2007. The

Daily discharge, 6 10 nearly one-fourth of the State of 5,000 highest water in cubic feet per second level below 4 15 Georgia. The Altamaha River is the in inches 0 land surface Precipitation, 2 20 third largest contributor of fresh­ O N D J F M A M J J A S Water level below water to the Atlantic Ocean on North 2007 2008 was recorded 0 25 land surface, in feet during Tropical 21 22 23 24 25 26 27 America’s eastern shore (Georgia August 2008 Humanities Council, 2009). The watershed extends from the upper Piedmont to the Storm Fay Lower Coastal Plain and encompasses the cities of Athens, Macon, Milledgeville, and in August parts of Atlanta (U.S. Geological Survey, 1975). when some locations in southwestern Georgia received more than 13 inches of rainfall during August 21–27, 2008 The peak flow recorded for the 2008 WY at Altamaha River near Baxley was 23,600 ft3/s, (Georgia Automated Environmental Monitoring Network, the seventh lowest peak flow in 51 years of record. Annual runoff was about half of the 2008). The water level in well 07H003 responds to seasonal long-term average. New historic low 7-day average discharge and historic low daily-mean change similarly to streamflow at nearby streamgage flows were observed from October through December and “much below normal” flow was Spring Creek near Iron City 02357000, which indicates observed from June through September. atmospheric, surface-water, and groundwater interactions.

3 Georgia’s Climate Response Network Well 16MM03 is located in 0 Hydrographs are presented on the Climate Response White County in northeastern 1 Tropical storm Fay Network Web site for wells with at least 5 years of continuous Georgia and is completed 2 in the crystalline-rock 3 data. The 2008 WY data are shown here for selected wells. aquifer. Water is stored in 4 the regolith and fractures, 5 and the water level is 6 16MM03 affected by precipitation and Daily mean water level below land surface, in feet 7 evapotranspiration (Cressler 1,000 0 02330450 EXPLANATION and others, 1983). Precipitation Surface 800 water station 1 Monitoring well can cause a rapid water-level rise in wells tapping aquifers 2 Streamgage 600 Blank overlain by thin regolith (Peck Groundwater where 3 400 level data are and others, 2009). The water missing 4 Sa va level was near a record low at n 200 n 5 Daily mean discharge, a the start of the 2008 WY and Daily mean water level

h in cubic feet per second

r below land surface, in feet e R v 0 6 i iv rarely rose above the historical e R r 8 O O c daily median. The highest c o 4 m n

e water level below land surface in inches u e 0

l Precipitation, g R O N D J F M A M J J A S e i was recorded during Tropical e v O e g 2007 2008 e R r ec Storm Fay in August when the 0 i h 6 v e e e r Dahlonega area received more 5 1 02223500 R i v than 10 inches of rainfall during 2 21T001 e 4 r 3 e August 24–28, 2008 (Georgia 3 e h 4 c Automated Environmental

in inches 2 o Altam 35P094 Water level 5 o aha Precipitation, h Monitoring Network, 2008). The 1 6 a Water level below t r 02203559 land surface, in feet t e v water level in well 16MM03 a i R 0 7 h R iv 22 23 24 25 26 27 28

C t e responds to seasonal change n r i August 2008 l similarly to streamflow F n a e at nearby streamgage Chattahoochee River at Helen 02330450, which 07H003 c O

c indicates atmospheric, surface-water, and groundwater interactions. i t n a l 02357000 t

A EXPLANATION Daily mean water level N Base modified from Range of historical daily U.S. Geological Survey 0 30 60 MILES minimum and maximum 1:2,000,000 digital data Historical median 0 30 60 KILOMETERS 2008 water year

Well 21T001 is located in 22 Well 35P094 is located 0 Laurens County in east-central in Chatham County in Well 35P094 Tropical storm Fay 26 2 Georgia and is completed southeastern Georgia 4 in a semiconfined part of 30 and is completed in the Upper Floridan aquifer. the surficial aquifer. 6 34 Water levels in semiconfined Water levels generally 8 areas of the Upper Floridan 38 rise rapidly during wet 10 Daily mean water level aquifer fluctuate seasonally Daily mean water level periods and decline below land surface, in feet below land surface, in feet 12 in response to variations 42 slowly during dry 10,000 0 200 0 in precipitation, evapo- 5 periods. During the 8,000 2 transpiration, and natural 10 2008 WY, the water 150 drainage or discharge 15 level was normal until 4 6,000 20 (Peck and others, 2009). A new several months of 100 25 record-low water level was 4,000 dry weather caused 6 30 recorded on December 14, the water level to dip 50 2,000 35 8 Daily mean discharge, Daily mean discharge, 2007. Water levels remained Daily mean water level Daily mean water level 40 below the historical in cubic feet per second in cubic feet per second below land surface, in feet below the historical daily 0 45 daily median from 0 10 below land surface, in feet 8 8 median for the entire May through July. In 4 4 in inches

2008 WY. The water levels in inches 0 August, Tropical Storm 0 Precipitation, reacted gradually during Precipitation, O N D J F M A M J J A S Fay brought relief with O N D J F M A M J J A S 2007 2008 2007 2008 and after Tropical Storm Fay 3 36.5 more than 5 inches 3 0 in August when the Dublin of rainfall during 37.0 2 area received more than 2 August 19–25, 2008 2 37.5 4 inches of rainfall during (Georgia Automated 4 August 21–27, 2008 (Georgia 38.0 Environmental in inches

in inches 1 1

Precipitation, 6 Automated Environmental Precipitation, 38.5 Monitoring Network, Water level below Water level below land surface, in feet Monitoring Network, 2008). land surface, in feet 0 39.0 2008). The water level 0 8 The water level in well 21T001 21 22 23 24 25 26 27 in well 35P094 responds 19 20 21 22 23 24 25 responds to seasonal change August 2008 to seasonal change August 2008 similarly to streamflow at similarly to streamflow nearby streamgage Oconee River near Dublin 02223500, which indicates at nearby streamgage Peacock Creek at McIntosh 02203559, which atmospheric, surface-water, and groundwater interactions. indicates atmospheric, surface-water, and groundwater interactions.

4 Lakes and Reservoirs 1,072 200,000 662 Top of conservation Major lakes and reservoirs Lake Sidney Lanier Hartwell Lake 180,000 660 throughout Georgia are 1,070 managed primarily by the U.S. 160,000 658 80,000 1,060 Army Corps of Engineers and 656 Water level 140,000 70,000 1,058 Georgia Power Company to 654 provide water to the public 60,000 120,000 and industry, flood protection, 1,056 652 50,000 100,000 power generation, wildlife 1,054 650 Inflow 80,000 management, and recreation. 40,000 Outflow 648 1,052 Vertical Datum of 1929 Vertical Vertical Datum of 1929 Vertical 60,000 Managing lakes and reservoirs 30,000 646 requires computer models, 1,050 20,000 40,000 644 climate forecasts, water- Elevation, in feet above National Geodetic Elevation, in feet above National Geodetic

1,048 in cubic feet per second Inflow and outflow, demand forecasts, and USGS 10,000 20,000 642 Inflow and outflow, in cubic feet per second Inflow and outflow, data to address all of these 0 1,046 0 640 O N D J F M A M J J A S O N D J F M A M J J A S needs. During the 2008 WY, 2007 2008 2007 2008 Georgia’s lakes and reservoirs Hartwell 332 continued to have record Carters 300,000 Lake Lake J. Strom Thurmond Lake minimum levels as a result 330 of the continued drought. 250,000 328 Emergency water-conservation Richard B Russell Lake 326 efforts by both State and local Allatoona Lake Lake Sidney J Strom Thurmond 200,000 324 authorities were in place for the Lanier Lake entire 2008 WY. The drought 322 has further emphasized the Sa 150,000 va 320 n n need for accurate, timely data a West h 318 R to make informed decisions Point i 100,000 v e Datum of 1929 Vertical regarding the management Lake r 316 and conservation of Georgia’s 50,000 314 Elevation, in feet above National Geodetic water resources. in cubic feet per second Inflow and outflow, 312 Lake Sidney Lanier Savannah 0 310 (Lake Lanier) is the primary Walter F O N D J F M A M J J A S George 2007 2008 drinking-water source for Lake n a e the Atlanta metropolitan c O 350,000 192 c area and is located on i t Walter F. George Lake n a 191 the Chattahoochee River. l t

A 300,000 Lake Lanier is the most 190 upstream reservoir in a series Lake Seminole 250,000 189 of reservoirs that include West (Jim Woodruff) Point Lake, Walter F. George 188 200,000 Lake, and Lake Seminole. Lake Lanier On July 4, 2008, the lake elevation was 187 186 had 3.7 times more outflow than inflow 15 feet below full pool and more than 150,000 and the pool elevation declined more half of the public launch sites were 185 than 7 feet from October through closed causing significant economic 100,000 184 Datum of 1929 Vertical December 2007. On December 26, 2007, impact (Lake Lanier Association 183 Lake Lanier reached an all-time historic Inc., 2008). 50,000 Elevation, in feet above National Geodetic low elevation of 1,050.79 feet. The Hartwell Lake is a manmade in cubic feet per second Inflow and outflow, 182 U.S. Army Corps of Engineers releases lake bordering Georgia and 0 181 O N D J F M A M J J A S water from Lake Lanier to manage water South Carolina on the Savannah, 2007 2008 in downstream reservoirs and to help Tugaloo, and Seneca Rivers. Hartwell (Data from U.S. Army Corps of Engineers, 2009a) assure a healthy environment for aquatic is the most upstream reservoir on the and animal life. Savannah River. Water is released to the Lake Lanier water levels increased downstream reservoirs Richard B. Russell Hartwell Lake water levels increased from from January through May 2008; and J. Strom Thurmond. These three lakes January through April 2008; however, however, the levels were still well below on the Savannah River are managed by the levels remained well below the average of the average of 1,067.5 feet. Water levels U.S. Army Corps of Engineers for water 657.0 feet. Water levels declined rapidly began to decline again in June. Outflows supply, power generation, and water quality from May to September 2008, and the lake were necessary to manage downstream needs of the Savannah River from below elevation approached a new historic low. reservoirs, including Walter F. George, to Thurmond Dam all the way to Savannah, J. Strom Thurmond Lake is the largest meet power-generation needs. The low Georgia, and the Atlantic Ocean (U.S. Army reservoir in Georgia, and it is used primar- lake levels adversely affected recreation. Corps of Engineers, 2009b). Hartwell Lake ily for flood control and power generation. The July 4 holiday is typically one of had twice as much outflow as inflow, and Water levels are affected by inflow from the busiest recreational times of the year the pool elevation fell more than 4 feet Hartwell Lake and Richard B. Russell for boating and other water recreation. from October through December 2007. Lake, but outflows remain nearly constant.

5 Tropical Storm Fay, August 17–29, 2008 Runoff Tropical Storm Fay provided Runoff is the average streamflow Georgia with some relief from drought per unit area, or streamflow yield. conditions during 2008. Fay dropped as Runoff for the 2008 WY was computed much as 20 to 25 inches of rain in the from data recorded at 174 streamgages southwest corner of the State and 3 to EXPLANATION in Georgia. The median runoff from Precipitation, 10 inches along the Georgia–Alabama in inches these gages is shown in the bar chart border (National Oceanic and Atmospheric 1 for selected drought years. The median Track 3 Administration, 2008). Georgia WSC 5 runoff for the 2007 and 2008 WYs was personnel made 133 discrete discharge 7 less than one-half of the average of the 10 measurements at 101 streamgaging stations 15 medians from 1955 to 2008 before, during, and after Tropical Storm 20 (U.S. Geological Survey, 2009b). Fay during August 21–31, 2008, to verify 25 Streamgage and extend streamflow ratings. with discharge 1.4 measurement duringTropical Storm Fay 1.2

1.0

0.8

0.6

0.4

Runoff, in millimeters per day 0.2

0 1955 1988 2000 2002 2007 2008 Average Upatoi Creek near Columbus, Georgia. A USGS 1955–2008 Drought water year technician making a flood measurement using an acoustic Doppler current profiler (ADCP). Photo by Andrew E. Knaak, USGS.

References City of Union City, 2008, Welcome to “The National Oceanic and Atmospheric Admin- U.S. Geological Survey, 2007, U.S. Geological Progressive City” City News, accessed istration, 2008, National Weather Service Survey Ground-Water Climate Response June 1, 2009, at http://ga-unioncity.civicplus. Advanced Hydrologic Prediction Service, Network: U.S. Geological Survey Fact Sheet com/CivicAlerts.aspx. 2008 precipitation maps for Georgia, 2007–3003, 4 p., accessed July 1, 2009, at accessed June 2, 2009, at http://water. http://pubs.usgs.gov/fs/2007/3003/. Cressler, C.W., Thurmond, C.J., and Hester, W.G., weather.gov. 1983, Groundwater in the greater Atlanta U.S. Geological Survey, 2008, U.S. Geological region, Georgia: Georgia Geological Survey Peck, M.F., Painter, J.A., and Leeth, D.C., Survey Groundwater Networks, Climate Information Circular 63, 144 p. 2009, Ground-water conditions and Response Network, accessed July 1, 2009, studies in Georgia, 2006–2007: U.S. at http://groundwaterwatch.usgs.gov/. Georgia Automated Environmental Monitoring Geological Survey Scientific Investigations Network, 2008, Climate data for Georgia, U.S. Geological Survey, 2009a, U.S. Geological Report 2009–5070, 86 p. accessed June 5, 2009, at http://www. Survey annual data report for Georgia, GeorgiaWeather.net. Regan, Jeffrey, and Cash, Tim, 2009, Monitor- water year 2008, accessed July 1, 2009, at ing and integrating water use data in North http://ga.water.usgs.gov/pubswdr.html. Georgia General Assembly, 2000, House Georgia drought response area, in Georgia U.S. Geological Survey, 2009b, WaterWatch—­ Bill 1362: Flint River Drought Protection Act, Water Resources Conference 2009, Athens, Current water resources conditions, accessed accessed July 1, 2009, at http://www.legis. GA, April 27–29, 2009, Proceedings: July 1, 2009, at http://waterwatch.usgs.gov. state.ga.us/legis/1999_00/fulltext/hb1362.htm. Athens, GA, Georgia Water Resources Georgia Humanities Council, 2009, The New Institute, 5 p., accessed October 30, 2009, Georgia Encyclopedia, accessed June 5, 2009, at http://www.gwri.gatech.edu/uploads/ at http://www.georgiaencyclopedia.com/ proceedings/2009/4.5.2_Regan.pdf. nge/Home.jsp. U.S. Army Corps of Engineers, 2009a, By Andrew E. Knaak, John K. Joiner, and Lake Lanier Association Inc., 2008, Effects Lake elevations, inflows and outflows, of low water levels, accessed July 1, 2009, accessed July 1, 2009, at http://www.sas. Michael F. Peck at http://www.lakelanier.com. usace.army.mil/. U.S. Army Corps of Engineers, 2009b, accessed For more information contact: National Oceanic and Atmospheric July 1, 2009 at http://www.sas.usace.army. Director, USGS Georgia Water Science Center Administration, 2008, National Weather mil/lakes/hartwell/intro.htm#funfacts. Service Advanced Hydrologic Prediction 3039 Amwiler Road, Suite 130 Service, 2008 Tropical Storm Fay maps, U.S. Geological Survey, 1975, Hydrologic Atlanta, Georgia 30360 accessed June 2, 2009, at http://water. unit map 1974, State of Georgia: U.S. 770-903-9100 weather.gov. Geological Survey, scale 1:500,000, 1 sheet.

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