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Water resources data for the 1999 water year for Georgia consists of records of stage, discharge, and water quality of streams; and the stage and contents of lakes and reservoirs published in one volume in a digital format on a CD-ROM. This volume contains discharge records of 121 gaging stations; stage for 13 gaging stations; stage and contents for 18 lakes and reservoirs; continuous water quality records for 10 stations; and the annual peak stage and annual peak discharge for 75 crest-stage partial-record stations. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Georgia.
Records of discharge and stage of streams, and contents or stage of lakes and reservoirs were first published in a series of U.S. Geological water-supply papers entitled, "Surface-Water Supply of the United States." Through September 30, 1960, these water-supply papers were in an annual series and then in a 5-year series for 1961-65 and 1966-70. Records of chemical quality, water temperature, and suspended sediment were published from 1941 to 1970 in an annual series of water-supply papers entitled, "Quality of Surface Waters of the United States." Records of ground-water levels were published from 1935 to 1974 in a series of water-supply papers entitled, "Ground-Water Levels in the United States." Water-supply papers may be consulted in the libraries of the principal cities in the United States or may be purchased from the U.S. Geological Survey, Branch of Information Services, Federal Center, Box 25286, Denver, CO 80225.
For water years 1961 through 1970, streamflow data were released by the U.S. Geological Survey in annual reports on a State-boundary basis prior to the two 5-year series water-supply papers, which cover this period. The data contained in the water-supply papers are considered the official record. Water-quality records for water years 1964 through 1970 were similarly released either in separate reports or in conjunction with streamflow records.
Beginning with the 1971 water year, water data for streamflow, water quality, and ground water are published in official Survey reports on a State-boundary basis. These official Survey reports carry an identification number consisting of the two-letter State abbreviation, the last two digits of the water year, and the volume number. For example, this volume is identified as "U.S. Geological Survey Water-Data Report GA-99-1." These water-data reports are for sale in various formats, by the National Technical Information Service, U.S. Department of Commerce, Springfield, VA 22161.
Additional information, including current prices, for ordering specific reports may be obtained from the District Office at the address provided at the end of this text in the section titled Access to USGS Water Data.
Station Identification Numbers
Each data station in this report, whether stream site, or other site, is assigned a unique identification number. This number is unique in that it applies specifically to a given station and to no other. The number usually is assigned when a station is first established and is retained for that station indefinitely. The system used by the U.S. Geological Survey to assign identification numbers for surface-water stations and for ground water well sites differ, but both are based on geographic location. The "downstream order" system is used for surface-water stations and the "latitude-longitude" system is used for wells and other off-stream sites.
Downstream Order System
Since October 1, 1950, the order of listing hydrologic-station records in Survey reports is in a downstream direction along the main stream. All stations on a tributary entering upstream from a mainstream station are listed before that station. A station on a tributary that enters between two mainstream stations is listed between them. A similar order is followed in listing stations on first rank, second rank, and other ranks of tributaries. This downstream order and system of indention show in stations are on tributaries between any two stations and the rank of the tributary on which each station is situated.
The station-identification number is assigned according to downstream order. In assigning station numbers, no distinction is made between partial-record stations and other stations; therefore, the station number for a partial-record station indicates downstream-order position in a list made up of both types of stations. Gaps are left in the series of numbers to allow for new stations that may be established; hence, the numbers are not consecutive. The complete number for each station, such as 02351890, which appears just to the left of the station name, includes the two-digit Part number "02" plus the downstream-order number "351890", which can be from six to 12 digits. Most of the station-identification numbers in this report are eight digits; however, up to 14 digit numbers are permissible.
Latitude-Longitude System
The identification numbers for wells and other off-stream sites, such as rain gages, are assigned according to the grid system of latitude and longitude. The number consists of 15 digits. The first six digits denote the degrees, minutes, and seconds of latitude, the next seven digits denote degrees, minutes, and seconds of longitude, and the last two digits (assigned sequentially) identify the wells or other sites within a 1-second grid. This site-identification number, once assigned, is a pure number, and has no location significance. In the rare instance where the initial determination of latitude and longitude are found to be in error, the station will retain its initial identification number; however, its true latitude and longitude will be listed in the LOCATION paragraph of the station description.