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–AltamahaO 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.