Return to Normal Streamflows and Water Levels: Summary of Hydrologic Conditions in Georgia, 2013 The U.S. Geological Survey (USGS) emphasize the need for accurate, timely data Water Resources Internet Tools South Atlantic Water Science Center (SAWSC) to help Federal, State, and local officials make Georgia office, in cooperation with local, informed decisions regarding the management Historically, hydrologic data collected State, and other Federal agencies, maintains and conservation of Georgia’s water resources by the USGS were compiled into annual data a long-term hydrologic monitoring network for agricultural, recreational, ecological, and reports; however, this method of publication of more than 340 real-time continuous-record water-supply needs and for use in protecting has been discontinued. Current and historical streamflow-gaging stations (streamgages), life and property. data are now available through the National including 10 real-time lake-level monitoring Drought conditions, persistent in the area Water Information System Web interface, or stations, 67 real-time surface-water-quality since 2010, continued into the 2013 WY. In NWISWeb, at http://waterdata.usgs.gov/nwis/ monitors, and several water-quality sampling February 2013, Georgia was free of extreme (U.S. Geological Survey, 2013a). programs. Additionally, the SAWSC Georgia (D3) drought conditions, as defined by the The USGS has several water resources office operates more than 180 groundwater U.S. Drought Monitor, for the first time Internet tools designed to provide users with monitoring wells, 39 of which are real-time. The since August 2010 due to extended periods current streamflow and groundwater data, wide-ranging coverage of streamflow, reservoir, of heavy rainfall (U.S. Drought Monitor, flood inundation maps, stream statistics, and and groundwater monitoring sites allows for a 2013). According to the Office of the State water-quality information (U.S. Geological comprehensive view of hydrologic conditions Climatologist, the city of Savannah recorded Survey, 2013b). Two of these Internet tools are across the State. One of the many benefits of 9.75 inches of rain in February 2013, the highest WaterNow and WaterAlert. WaterNow, avail- this monitoring network is that the analyses of monthly total in February out of 143 years of able at http://water.usgs.gov/waternow/, allows the data provide a spatially distributed overview record. Macon and Columbus also received users to request current data for a USGS site by of the hydrologic conditions of creeks, rivers, record rainfalls in February 2013. Above- using a mobile phone through text messaging reservoirs, and aquifers in Georgia. normal precipitation continued in June 2013, or by email. WaterAlert, available at http:// Streamflow and groundwater data and the cities of Augusta and Savannah recorded water.usgs.gov/wateralert/, will notify a user are verified throughout the year by USGS the wettest June on record. In July, precipitation by text message or email when a user-defined hydro­graphers. Hydrologic conditions are for the entire State of Georgia was 3.53 inches threshold is exceeded at a real-time USGS site. determined by comparing the results of above normal (Dunkley, 2013). Above-normal statistical analyses of the data collected rainfall from February to September 2013 Selected USGS Water Resources Internet Tools during the current water year1 (WY) to increased streamflow and raised groundwater historical data collected over the period of levels, and lakes and reservoirs were raised USGS National Water Information System (NWIS) record. Changing hydrologic conditions to full-pool elevations. http://waterdata.usgs.gov/nwis

Quarterly Hydrologic Conditions in Georgia for 2013 WY, Based on Drainage Basin Runoff A. 10/01/12–12/31/12 B. 01/01/13–03/31/13 C. 04/01/13–06/30/13 D. 07/01/13–09/30/13 ­sample

GEORGIA Augusta

Macon Columbus Savannah USGS WaterNow http://water.usgs.gov/waternow/

These maps represent hydrologic conditions during the 2013 WY EXPLANATION compared to available historical data. Runoff, or flow per unit area, is Percentile classes a goodFigure indicator 1 of precipitation and streamflow conditions for a given Highest basin (Langbein and Iseri, 1960). Runoff was calculated for each basin Much above normal, >90 and is presented uniformly over the entire basin area. Only streamflow Above normal, 76 to 90 stations with a complete daily-flow dataset for the 2013 WY were used Normal, 25 to 75 USGS WaterAlert (U.S. Geological Survey, 2013c). For the first quarter of the 2013 WY Below normal, 10 to 24 http://water.usgs.gov/wateralert/ (October–December 2012, fig. 2A), the majority of the State was Much below normal <10 observing “below normal” (10 to 24 percentile class), “much below Lowest normal” (less than 10 percentile class), and “lowest” runoff conditions.

FRM: [email protected] During the second quarter of the 2013 WY (January –March 2013, fig. 2B ), the majority of the State MSG: 144 cfs Streamflow, 2013-11-10 9:42:00 Scioto River below O’Shaughnessy Dam nr received above-normal precipitation, and runoff conditions returned to normal (25 to 75 percentile Dublin, OH h p://water.usgs.gov/bns? YUhd6:03221000 class) for the majority of the State. During the fourth quarter (July– September 2013, fig. 2D ), runoff (From U.S. conditions in the majority of the State were “above normal” (76 to 90 percentile class), “much Geological above normal” (greater than 90 percentile class), and “highest” on record. Survey, 2013b)

U.S. Department of the Interior Fact Sheet 2015 –3024 U.S. Geological Survey March 2015 Figure 2. Daily Discharge and 7-Day Average Streamflow Conditions, 2013 Water Year

CUMBERLAND PLATEAU 02398000 Chattooga River R BLUE EXPLANATION 02337000 Sweetwater Creek a g RIDGE SOUTH Chattooga River at Summerville, Ga. 02398000 at Summerville, Georgia o Sweetwater Creek near Austell, Ga. 02337000 o t [Map] near Austell, Georgia t CAROLINA a h 10,000 The Chattooga River flows 10,000 C 02398000 River basin boundary Sweetwater Creek is a major tribu­ VALLEY Physiographic boundary tary of the Chattahoochee River from the northwestern corner AND Coosa– 02213000 1,000 of Georgia, in the Blue Ridge RIDGE Tallapoosa– Streamgage and number in the Piedmont Physiographic­ Weiss Tennessee Physiographic Province, into Lake Sweetwater Province­ (U.S. Geological Survey, 1,000 reek C PIEDMONT Savannah–Ogeechee 1975). For the first half of the 2013 WY, 100 Alabama where it flows into Sa Atlanta va 02337000 n n 7-day average streamflow conditions Weiss Lake (U.S. Geological Jackson a h r Lake e R were “below normal” to “much 10 Survey, 1975). For the majority v i i v e 100 R GEORGIA r below normal,” and record low 7-day in cubic feet per second of the 2013 WY, 7-day average in cubic feet per second 7-day average discharge, Ocmulgee–Altamaha 7-day average discharge, streamflow conditions were O average streamflows were observed 1 40 c 02213000 Oconee– o n in November and December. “normal” to “much above e e O 100,000 100,000 ge ec Steady precipitation in the area, normal.” Daily discharge for h e e R R starting in December, brought in 10,000 most of the 2013 WY was in the 10,000 iv e i e r v e O e much needed rainfall, and the 7-day “maximum” range. New record c r h m c COASTAL PLAIN o u 1,000 1,000 l average streamflows fluctuated high daily discharges were o g Altam h e r ah a e a t e v mostly between “normal” and observed in January, April, t Ri Ri a ve 100 100 h r “much above normal” for the rest May, June, and July. C n a e

Satilla–Suwannee– c Daily discharge, Daily discharge, of the 2013 WY. New minimum daily 10 O 10 r St Marys–Ochlockonee Chattahoochee–Flinte c v i

i t mean discharges were observed in in cubic feet per second

in cubic feet per second R t n e a n e l 1 ALABAMA i t October, November, and December, 1 l h

c A F o r OND JFMAMJJAS OND JFMAMJJAS o e c v followed by streamflows in the la i 2012 2013 h R 2012 2013 FLORIDA t

i 02318500 “median” and “maximum” ranges W N for the remainder of the 2013 WY.

02213000 Ocmulgee River 02318500 Withlacoochee River Ocmulgee River at Macon, Ga. 02213000 EXPLANATION Withlacoochee River at US 84 near Quitman, Ga. 02318500 at Macon, Georgia [Graphs] at US 84, near Quitman, Georgia 50,000 50,000 The Ocmulgee River flows 7-Day Average Discharge The Withlacoochee River flows out of Jackson Lake and joins Hydrographs show the 7-day average discharge for 2013 as compared to in the Suwannee River Basin 10,000 the Oconee River to form the 10,000 historical 7-day averages. Data are categorized in percentile ranges from in the southern coastal plain of Altamaha River in the Coastal “much above normal” (greater than the 90th percentile)EXPLANATION to “much below Georgia (U.S. Geological Survey, 1,000 Plain Physiographic Province in normal” (less than the 10th percentile) (U.S. Geological[Graphs] Survey, 2013c). 1975). For much of the 2013 WY, 1,000 central Georgia (U.S. Geological Historical 7-day average discharge— 7-day average streamflow 100 Survey, 1975). At the start of Percentile in parentheses conditions were “normal” to

the 2013 WY, streamflows were Much above normal (≥90) “much above normal,” and in cubic feet per second 7-day average discharge, 10 in cubic feet per second approaching a new record low. 7-day average discharge, 100 AboveEXPLANATION normal (76 to 89) record-high 7-day average 5 Normal (25 to 75) Starting in December 2012, [Graphs] streamflows were observed 100,000 Below normal (11 to 24) 100,000 daily discharge increased Historical 7-day average discharge— during March, July, and August. Much Percentile below innormal parentheses (≤10) and fluctuated between the Daily discharge was mostly 10,000 10,000 2012 2013 2013Much water above year normal 7-day ( 90) “median” and “maximum” ≥ Aboveaverage normal discharge (76 to 89) in the “maximum” range from ranges of historical daily mean 1,000 February to September. New 1,000 Daily Discharge Normal (25 to 75) flow. In February 2013, the HistoricalBelow normal daily-mean (11 to 24) discharge maximum daily-mean discharges 100 100 7-day average discharge was Hydrographs show 2013 daily-mean discharge,MuchMaximum in cubic below feet normal per ( ≤second,10) as were recorded during February, compared to historical minimum and median dischargeMedian for the entire period Daily discharge, mostly “normal,” with several Daily discharge, 10 2012 2013 2013 water year 7-day March, July, and August. 10 of record (U.S. Geological Survey, 2013a). Minimumaverage discharge

days also having “much above in cubic feet per second in cubic feet per second normal” flows. 1 2013 daily-mean discharge 1 OND JFMAMJJAS Historical daily-mean discharge OND JFMAMJJAS 2012 2013 2012 2013 Maximum 2012 2013 Median Minimum 2013 daily-mean discharge 2012 2013

2 3 Climate Response Network Well 16MM03, White County Well 16MM03 is in White County in northeastern Georgia and 1,550 0 1,200 The USGS maintains a network of groundwater wells to monitor the effects of droughts and other climate variability on groundwater is completed in the crystalline-rock aquifer. Water is stored levels. These wells are part of the Climate Response Network, which is designed to measure the effects of climate on groundwater levels in 1 1,000 in the regolith and fractures, and the water level is affected by precipitation and evapotranspiration (Cressler and others, unconfined aquifers or near-surface confined aquifers where pumping or other human influences on groundwater levels are minimal (U.S. 1,548 2 16MM03 800 1983). Precipitation can cause a rapid water-level rise in wells Geological Survey, 2007, 2013d). The national network consists of about 130 wells, of which 15 are located in Georgia. These wells are 3 monitored as part of the USGS Groundwater Resources and Cooperative Water Programs. Current conditions of groundwater wells in the 600 tapping aquifers overlain by thin regolith (Peck and others, 1,546 4 2013). The water level in well 16MM03 responds to seasonal Climate Response Network can be accessed online at http://groundwaterwatch.usgs.gov/. The hydrographs presented in figure 4 are for 400 5 selected wells in Georgia having at least 5 years of continuous data. change similarly to streamflow at the nearby streamgage on the

1,544 Depth to water level 200 Chattahoochee River at Helen, Ga. (02330450), which indicates 6 Daily mean discharge, 02330450 in cubic feet per second below land surface, in feet 7 0 atmospheric, surface-water, and groundwater interactions. As Elevation above NGVD 29, in feet the drought continued into the 2013 WY, new minimum daily 16 mean water levels, approximately 5.5 feet below land surface, 16MM03 EXPLANATION 02330450 02330450 [Map] 12 were recorded at the end of November and beginning of 02333500 December. In December and January, the area received more 16MM03 Georgia Climate 8 than 7 and 12 inches of precipitation, respectively, and the water Response Network in inches 4 precipitation, monitoring well Total monthly level in well 16MM03 fluctuated above and below the historical and identifier 0 daily median. New maximum daily mean water levels, ranging 11FF04 02330450 O ND J F M A M JJ A S Atlanta Streamgage and from 1.5 to 2.5 feet below land surface, were recorded during 2013 number 2012 January, April, May, June, and July. 21BB04 GEORGIA 11AA01 Aquifers in Georgia [Surficial system (brown) 12Z001 present throughout State] Well 35P094, Chatham County 19 0 16,000 SC Blank where 17 2 data are missing U.S. Climate Response Network can be 02223500 Well 35P094 is in Chatham County in southeastern Georgia and Dublin Crystalline-rock 15 4 35P094 12,000 accessed online at http://groundwaterwatch. GA 21T001 is completed in the surficial aquifer. Water levels generally Upper usgs.gov/. AL 02224500 35P094 13 6 rise rapidly during wet periods and decline slowly during dry Floridan 02202600 8,000 FL 11 8 periods. The water level in well 35P094 responds to seasonal change similarly to streamflow at the nearby streamgage 13M007 02203518 9 10 4,000 on the Canoochee River at Bridge 38, at Fort Stewart, Ga. Depth to water level 7 12 02203518 Daily mean discharge, in cubic feet per second (02203518), which indicates atmospheric, surface-water, and

07H002 13J004 below land surface, in feet 5 14 0 groundwater interactions. The water level in well 35P094 was 10G313 Elevation above NGVD 29, in feet EXPLANATION 02356000 12 approximately 1 to 2 feet below the historical daily median at [Top graphs] 07H003 Bainbridge 02357000 10 the start of the 2013 WY. In February, the area received more Groundwater levels 02203518 8 than 10 inches of precipitation for the month, and the water Range of minimum and maximum historical daily means 0 30 60 MILES 6 levels rose nearly 6 feet, remaining above the historical daily 4 Historical daily median 0 30 60 KILOMETERS in inches median through the end of the WY. precipitation, 2013 daily mean Total monthly 2 Daily mean stream discharge 0 2012 2013 O ND J F M A M JJ A S [NGVD 29, National Geodetic 2012 2013 Vertical Datum of 1929]

Well 21T001 is in Laurens County in east-central Georgia and Well 07H003 is in Miller County in southwestern Georgia and Well 07H003, Miller County Well 21T001, Laurens County is completed in the semiconfined part of the Upper Floridan 157 –10 14,000 238 20 30,000 is completed in the surficial aquifer, which is an unconfined aquifer, which is an unconfined aquifer in this area. Water 12,000 21T001 levels in semiconfined areas of the Upper Floridan aquifer aquifer in this area (Peck and others, 2013). Water levels 07H003 233 25 25,000 in this well generally rise rapidly during wet periods and 167 0 10,000 fluctuate seasonally in response to variations in precipitation, 20,000 evapotranspiration, and natural drainage or discharge (Peck and decline slowly during dry periods. The water level in well 8,000 228 30 07H003 responds to seasonal change similarly to streamflow 177 10 15,000 others, 2013). The water level in well 21T001 responds to seasonal 6,000 at the nearby streamgage on Spring Creek near Iron City, Ga. 223 35 change similarly to streamflow at the nearby streamgage on 02224500 10,000 187 4,000 Oconee River near Mount Vernon, Ga. (02224500), which indicates (02357000), which indicates atmospheric, surface-water, and 20 218 40 Depth to water level

Depth to water level 5,000 Daily mean discharge, 02357000 2,000 Daily mean discharge, atmospheric, surface-water, and groundwater interactions. In in cubic feet per second groundwater interactions. The water level in well 07H003 was in cubic feet per second below land surface, in feet below land surface, in feet the 2013 WY, well 21T001 recorded new minimum daily median below the historical daily median at the start of the 2013 WY 197 30 0 213 45 0 Elevation above NGVD 29, in feet until February when the area received more than 10 inches Elevation above NGVD 29, in feet water levels, 40 to 42 feet below land surface, from October to 16 12 February. In February, the area received more than 11 inches of of precipitation for the month and the water level rose 14 feet 10 12 02357000 02224500 precipitation, and the water level in well 21T001 rose from 40 to and was above the historical daily median. The water level 8 slowly declined below the historical daily median from March 8 6 31 feet below land surface and was above the historical daily 4 median from May through the remainder of the water year. In July, in inches through June. New maximum daily mean water levels were in inches 4 precipitation, precipitation, Total monthly recorded during the months of July and August after the Total monthly 2 August, and September, new maximum daily mean water levels 0 0 were recorded after the area received more than 8 inches of area received more than 13 and 9 inches of precipitation, O ND J F M A M JJ A S O ND J F M A M JJ A S precipitation in July and nearly 7 inches in August. respectively, during these months. 2012 2013 2012 2013

4 5 Discrete and Continuous Water-Quality Conditions Chattahoochee River near Fairburn, Ga. 02337170 Yellow River at GA 124 near Lithonia, Ga. 02207120 typically greater during stormflow samples compared to base-flow samples because these constituents are washed from the land and in Georgia The Chattahoochee River near Fairburn, Ga., station (02337170), located Yellow River station 02207120, located in Gwinnett County, impervious surfaces into streams during periods of rainfall runoff just south of Atlanta in the Metro North Georgia Water Planning District Water-quantity and quality information are both important Ga., in the Altamaha River Basin, has a drainage area of 162 square and suspended in the water column, demonstrating a relation between planning region, has a drainage area of 2,060 square miles. Water use for this for ensuring adequate water availability for human consumption, miles. During the 2013 WY, real-time continuous turbidity was water quality and water quantity (graphs below). stream reach is classified as “fishing” under Georgia Code 391-3-6-.03, which industrial uses, and aquatic ecosystems. Water-quality conditions measured, and 10 total suspended solids (TSS) samples were Real-time continuous specific-conductance measurements were requires the daily mean dissolved oxygen concentration in the stream be equal are related strongly to water quantity. Precipitation and streamflow collected, 7 during stormflow and 3 during base flow. Turbidity is a collected at this station during the 2013 WY. Specific conductance to or greater than 5.0 milligrams per liter (Georgia Department of Natural conditions are primary agents of delivery and transport of both measure of water clarity and light reflected off particles in streamflow is a measure of dissolved ionic constituents, such as salts, in water. Resources, 2013). No daily mean dissolved oxygen level fell below point- and nonpoint-source contaminants (Hirsch and others, 2006). caused by clay, silt, and fine suspended inorganic and organic matter; Specific conductance and total dissolved solids were typically lower the “fishing” criteria at station 02337170 during the 2013 WY (graph below). therefore, TSS and turbidity react similarly during changing stream- in samples collected during stormflow because dissolved constituents Georgia Environmental Protection Division flow conditions. Chronic levels of suspended materials in streams are in streams can be diluted during rainfall runoff, as compared to lower Urban Water-Quality Program often the cause of stream impairment (U.S. Environmental Protection flows. At times, however, some dissolved constituents are transported The USGS provides the Georgia Department of Natural Numerous real-time water-quality monitors are co-located at streamflow Agency, 2012). TSS concentrations and turbidity levels were during higher discharges. Resources Environmental Protection Division (GaEPD) and the stations around the Atlanta metropolitan area: Gwinnett County (15), Fulton public with a relevant, nationally consistent database of long- County (8), Dekalb County (15), and Douglas County (1). These water-quality term water-quality data, which assists the GaEPD in meeting its monitors collect water-temperature, specific-conductance, and turbidity data; 02207120 Yellow River at GA 124, near Lithonia, Ga., total suspended sediment (TSS) responsibilities under the Clean Water Act. The USGS-GaEPD in addition, several monitors collect pH and dissolved oxygen data. Some of 4,000 200 discrete water-quality sampling program is designed to collect these parameters can be used as surrogates for other constituents. For example, 180 data systematically, regardless of hydrologic conditions. Water- specific conductance is a useful surrogate for total dissolved solids or other 3,500 quality data for Georgia streams are available to the public at dissolved constituents. Turbidity can be used as a surrogate for suspended 160 http://waterdata.usgs.gov/ga/nwis/qw/. In addition, the USGS- 3,000 sediment as well as other constituents that adhere to suspended-sediment Discharge 140 GaEPD program collects continuous water-quality data at three 300 particles, such as heavy metals, pesticides, and fecal coliform. Relating sites, including the Chattahoochee River near Fairburn, Ga. 2,500 120 streamflow to continuous water-quality data and discrete water-quality Turbidity samples can facilitate surrogate identification, be used to evaluate the effects 100 EXPLANATION 240 of watershed characteristics on constituent concentrations, and determine 2,000 300 Water planning region name 150 80 Altamaha water-quality trends. Data like these are summarized in scientific investigations reports, such as Watershed Characteristics and Water-Quality Trends and Loads 1,500 60 Coastal Georgia in 12 Watersheds in Gwinnett County, Georgia (Joiner and others, 2014). Atlanta Coosa–North Georgia 40 1,000 02337170 Lower Flint–Ochlockonee GWINNETT 20 Metro North Georgia DIscharge, in cubic feet per second 500 Water Planning District Turbidity, in Formazin Nephelometric units 31 0 Middle Chattahoochee 18 DOUGLAS 3 14 5 4 Middle Ocmulgee 0 –20 Savannah–Upper Ogeechee Atlanta 02207120 Suwannee–Satilla DE KALB 02207120 Yellow River at GA 124, near Lithonia, Ga., total dissolved solids (TDS) FULTON 4,000 350 Upper Flint GEORGIA Upper Oconee EXPLANATION 3,500 300 2013 USGS-GaEPD water- Continuous water-quality monitoring site quality station Water temperature (WT), specific 3,000 Discharge Discrete Continuous conductance (SC), and turbidity 57 Specific conductance 250 WT, SC, turbidity, pH, and dissolved oxygen (DO) 2,500 WT, SC, pH, and DO 200 Figure 6. 72 02337170 Chattahoochee River near Fairburn, GA 2,000 68 12 18,000 54 150 1,500

11 at 25 degrees Celsius 16,000 100 1,000 10 Figure 7. DIscharge, in cubic feet per second 14,000 50 9 500 80 110 120 80 Dissolved oxygen 160

81 Specific conductance, in microsiemens per centimeter 8 12,000 0 0 Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. 7 2012 2013 10,000 6 GaEPD daily mean DO EXPLANATION minimum threshold (5 mg/L) 8,000 5 Discrete sample and concentration of TSS and TDS, in milligrams per liter 4 Discharge 6,000 160 Base flow 120 Stormflow

3 4,000

2 Daily mean discharge, in cubic feet per second Daily mean dissolved oxygen, in milligrams per liter 2,000 1

0 0 Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept. 2012 2013

6 7

Figure 6. Figure 7. Allatoona Lake 160,000 850 Lake SC 120,000 840 Sidney Hartwell Lake Lanier Richard B 80,000 830 Weiss Allatoona Russell Lake Lake Lake J Strom Atlanta 40,000 820 Thurmond Lake Lake West Sinclair 0 810 Point Lake Hartwell Lake GEORGIA 14,000 670 Savannah

12,000 n Walter F a 660 e 10,000 George c O Lake c 8,000 i AL t 650 n a 6,000 l FL t 4,000 A 640 Lake Seminole 2,000 (Jim Woodruff) 0 630

Lake Sidney Lanier 160,000 1,075

120,000 1,065 80,000 1,055 40,000

0 1,045

Total monthly inflow and outflow, in cubic feet per second monthly inflow and outflow, Total West Point Lake 350,000 640 300,000 635

250,000 Datum of 1929 elevation, in feet above National Geodetic Vertical Water-level 200,000 630 150,000 625 100,000 620 50,000 0 615 OND JFMAM JJAS 2012 2013 Lakes and Reservoirs than the outflow, EXPLANATION Allatoona Lake 160,000 850 and the lake level Inflow Inflow and outflow data Major lakes and reservoirs throughout increased nearly from U.S. Army Corps Lake SC Outflow of Engineers (2013b) 120,000 840 Sidney Hartwell Lake Georgia are managed primarily by the U.S. 16 feet to a full- Lanier Army Corps of Engineers and Georgia Power pool elevation of Lake water level Richard B 80,000 830 Weiss Allatoona Russell Lake Company to provide water for public and 1,072.24 feet, and Top of conservation pool Lake Lake J Strom industrial use, flood protection, power gener­ Atlanta remained near full 40,000 820 Thurmond ation, wildlife management, and recreation. Lake pool for the remainderFigure of the5. 2013 WY. Lake To manage lakes and reservoirs, tools such as West Sinclair West Point Dam provides flood protection 0 810 Point computer models that rely on real-time USGS and hydroelectric power to Troup County. The Lake streamflow data help to predict changes in Hartwell Lake GEORGIA water-level elevation of West Point Lake at 14,000 670 climatic conditions and water demands. the start of the 2013 WY was approximately Savannah 12,000 n Lake Sidney Lanier on the Chattahoochee Walter F a 10 feet below full pool. From December 2012 660 e River is the primary drinking-water source for 10,000 George c O to January 2013, the water level was raised Lake c 8,000 i much of Metropolitan Atlanta. Lake Sidney AL t 13 feet to maintain a level near the top of 650 n a 6,000 l Lanier is the farthest upstream reservoir in a conservation pool for the remainder of the FL t series of reservoirs that include West Point 4,000 A water year. 640 Lake Seminole Lake, Walter F. George Lake, and Lake Allatoona Lake is on the Etowah River 2,000 (Jim Woodruff) Seminole. On December 23, 2012, Lake and is managed by the U.S. Army Corps of 0 630 Sidney Lanier reached the 2013 WY minimum Engineers. During the 2013 WY, the water Lake Sidney Lanier elevation of 1,056.33 feet. From January to level of Allatoona Lake remained above or 160,000 1,075 April 2013, the inflow was 3.6 times greater just below the top of conservation pool. Hartwell Lake is the most upstream major 120,000 1,065 Lake SC reservoir on the Savannah River in a series Sidney Hartwell Lake 80,000 Lanier of reservoirs that include Richard B. Russell Richard B and J. Strom Thurmond Lakes. These three 1,055 Weiss Allatoona Russell Lake 40,000 Lake lakes on the Savannah River are managed by Lake J Strom Atlanta the U.S. Army Corps of Engineers for water Thurmond 0 1,045 Lake Lake supply, power generation, and water-quality West Sinclair needs of the Savannah River from below in cubic feet per second monthly inflow and outflow, Total West Point Lake Point 350,000 640 Lake Thurmond Dam to Savannah, Georgia, and the GEORGIA 300,000 Atlantic Ocean (U.S. Army Corps of Engineers, 635

Savannah 2013a). During the 2013 WY, Hartwell Lake 250,000 Datum of 1929 elevation, in feet above National Geodetic Vertical Water-level 630 n 200,000 Walter F a reached a minimum elevation of 644.77 feet e George c on December 15, 2012. Between January and 150,000 O 625 Lake c i AL t April 2013, the inflow was 2 times greater than 100,000 n

a 620 l outflow, and the lake level increased more than FL t 50,000 A 20 feet to a full-pool elevation of 664.79 feet. 0 615 Lake Seminole (Jim Woodruff) The water-level elevation remained near full OND JFMAM JJAS pool for the remainder of the 2013 WY. 2012 2013 EXPLANATION Inflow Inflow and outflow data Peck, M.F., Gordon, D.W., and Painter, J.A., 2013, U.S. Geological Survey, 2013a,from U.S.National Army Corps Water References Cited Outflow of Engineers (2013b) Groundwater conditions in Georgia, 2010 –2011: Information System: Web Interface, accessed Cressler, C.W., Thurmond, C.J., and Hester, W.G., U.S. Geological Survey Scientific Investigations July 1, 2014, atLake http://waterdata.usgs.gov/nwis water level . 1983, Groundwater in the greater Atlanta region, Report 2013–5084, 63 p. (Also available at U.S. Geological Survey,Top of conservation2013b, U.S. Geologicalpool Georgia: Georgia Geological Survey Information http://pubs.usgs.gov/sir/2013/5084/.) Survey water resources Internet tools: U.S. Circular 63, 15 p. U.S. Army Corps of Engineers, 2013a, Hartwell Dam Geological Survey Fact Sheet 2013–3072, 2 p., Dunkley, N., 2013, 2013 Climate summaries: Georgia and Lake: U.S. Army Corps of Engineers, Savannah accessedFigure July 1, 5. 2014, at http://pubs.usgs.gov/ Department of Natural Resources, Environmental District, accessed June 1, 2013, at http://www. fs/2013/3072/. Protection Division, accessed August 14, 2014, at sas.usace.army.mil/About/DivisionsandOffices/ U.S. Geological Survey, 2013c, WaterWatch— https://epd.georgia.gov/office-state-climatologist. OperationsDivision/HartwellDamandLake.aspx. Current water resources in Georgia, accessed Georgia Department of Natural Resources, Environ- U.S. Army Corps of Engineers, 2013b, Lake July 1, 2011, at http://waterwatch.usgs.gov/. mental Protection Division, 2013, Existing rules elevations, inflows and outflows, accessed U.S. Geological Survey, 2013d, USGS groundwater and corresponding laws, 391-3-6 Water quality June 1, 2013, at http://www.sas.usace.army.mil/. watch, Climate Response Network, accessed control, accessed July 16, 2013, at https://epd. U.S. Drought Monitor, 2013, U.S. Drought July 1, 2014, at http://groundwaterwatch.usgs.gov/. georgia.gov/georgia-water-quality-standards. Monitor maps and data, accessed July 1, 2014, Hirsch, R.M., Hamilton, P.A., and Miller, T.L., 2006, at http://droughtmonitor.unl.edu/MapsAndData/ By Andrew E. Knaak, Kerry Caslow, U.S. Geological Survey perspective on water- DataTables.aspx?southeast. and Michael F. Peck quality monitoring and assessment: Journal of U.S. Environmental Protection Agency, 2012, For more information contact: Environmental Monitoring, v. 8, p. 512–518. Georgia water quality assessment report, Georgia Director, USGS South Atlantic Water Joiner, J.K., Aulenbach, B.T., and Landers, M.N., cumulative TMDLs by pollutant, accessed Science Center, Georgia 2014, Watershed characteristics and water- July 1, 2014, at http://ofmpub.epa.gov/waters10/ quality trends and loads in 12 watersheds in attains_state.control?p_state=GA. 1770 Corporate Drive Norcross, Georgia Gwinnett County, Georgia: U.S. Geological U.S. Geological Survey, 1975, Hydrologic unit (770) 624-6700 Survey Scientific Investigations Report map—1974, State of Georgia: U.S. Geological 2014–5141, 79 p., accessed February 27, 2015, Survey, scale 1:500,000, 1 sheet. http://ga.water.usgs.gov/ at http://dx.doi.org/10.3133/sir20145141. U.S. Geological Survey, 2007, U.S. Geological Langbein, W.B., and Iseri, K.T., 1960, General Survey ground-water Climate Response 1Water year is the period October 1 through introduction and hydrologic definitions: U.S. Network: U.S. Geological Survey Fact Sheet September 30 and is designated by the year in which Geological Survey Water-Supply Paper 1541–A, 2007–3003, 4 p., accessed July 1, 2009, at it ends. For example, the 2013 water year began on 29 p. http://pubs.usgs.gov/fs/2007/3003/. October 1, 2012, and ended on September 30, 2013.

ISSN 2327– 6932 (online) 8 http://dx.doi.org/10.3133/fs20153024