FLOODS OF APRIL 1979, MISSISSIPPI, ALABAMA, AND GEORGIA by George W. Edelen, Jr., K.V. Wilson, and Joe R. Harkins, U.S. Geological Survey and John F. Miller and Edwin H. Chin, National Weather Service, National Oceanic and Atmospheric Administration Prepared by the U.S. Geological Survey in cooperation with the National Oceanic and Atmospheric Administration U.S. Geological Survey Professional Paper 1319 TABLE OF CONTENTS Glossary Abstract Introduction Acknowledgments Meteorological setting     Antecedent conditions     Early spring storms         March 3-4         March 10-11, 14, and 21         March 23-24         April 1-4         April 8-9     Major storm event: April 11-13         500-mb features         850-mb features         Surface weather features         Satellite imagery         Precipitation distribution General description of floods Magnitude of floods Flood damages Flood frequency Reservoirs Major river basins of eastern Gulf of Mexico     Coosa River basin     Tallapoosa River basin     Alabama River basin     Tombigbee River basin         Tombigbee River upstream from Gainesville, Ala.         Tombigbee River downstream from Gainesville, Ala.     Pascagoula River basin     Pearl River basin     Lower Mississippi River basin         Big Black River basin Flood-crest stages Streamflow velocities     Velocity changes during peak discharges     Velocity distribution through bridge openings Flood hydrograph data Ground-water fluctuations     Numbering system for wells Salinity and temperature data, Mobile Bay and Gulf of Mexico Aerial photography Selected references FRONTISPIECE. Sequence of photographs showing the destruction of the bridge on State Highway 50 over the Tallapoosa River below Martin Dam near Tallassee, Ala., about 4:30 p.m., April 14, 1979. FIGURES 1. Area affected by floods on the Alabama, Big Black, Chattachoochee, Chickasawhay, Coosa, Pearl, and Tombigbee Rivers and their tributaries in April 1979 2. Significant meteorological features associated with the storm of March 3-4, 1979 3. Isohyetal analysis of storm rainfall March 3-4, 1979 4. Significant meteorological features associated with the storm of March 23-24, 1979 5. Isohyetal analysis of storm rainfall, March 23-24, 1979 6. Significant meteorological features associated with the storm of April 1-4, 1979 7. Isohyetal analysis of storm rainfall, April 1-4, 1979 8. 500-mb analyses     A. 0600 CST, April 11, 1979     B. 1800 CST, April 11, 1979     C. 0600 CST, April 12, 1979     D. 1800 CST, April 12, 1979     E. 0600 CST, April 13, 1979     F. 1800 CST, April 13, 1979 9. 850-mb analyses     A. 0600 CST, April 11, 1979     B. 1800 CST, April 11, 1979     C. 0600 CST, April 12, 1979     D. 1800 CST, April 12, 1979     E. 0600 CST, April 13, 1979     F. 1800 CST, April 13, 1979 10. Surface analyses     A. 0600 CST, April 11, 1979     B. 1800 CST, April 11, 1979     C. 0600 CST, April 12, 1979     D. 1800 CST, April 12, 1979     E. 0600 CST, April 13, 1979     F. 1800 CST, April 13, 1979 11. Analysis of hourly observations at 1500 CST, April 12, 1979 12. GOES visual image for 0730 CST, April 12, 1979, with major features of surface weather map superimposed 13. Enhanced GOES infrared images (Mb curve)     A. 0000 CST, April 12, 1979     B. 0230 CST, April 12, 1979 14. Radar summary map     A. 0535 CST, April 12, 1979     B. 1435 CST, April 12, 1979 15. Rawinsonde plot, 1800 CST, April 12, 1979     A. Jackson, Miss.     B. Centreville, Ala. 16. Isohyetal analysis of storm rainfall, April 11-14, 1979 17. Rainfall mass curves 18. Map showing location of flood determination sites 19. Comparison of April 1979 peak discharges with maximum known flood peaks in Mississippi and Alabama 20-23. Hydrographs of discharge at selected gaging stations:     20. Coosa River basin in Alabama, April 1-16, 1979     21. Tallapoosa River basin in Alabama, April 3-22, 1979     22. Cahaba River basin in Alabama, April 10-22, 1979     23. Noxubee River at Macon, Miss., and near Geiger, Ala, and Sucarnoochee River at Livingston, Ala., April 2-23, 1979 24. Photograph showing overflow of Tombigbee River at Demopolis, Ala., April 19, 1979 25-27. Hydrographs of discharge at selected gaging stations:     25. Valley Creek in the Black Warrior River in Alabama, April 2-21, 1979     26. North River and Black Warrior River in Alabama, April 2-21, 1979     27. Pearl River basin at and upstream from Jackson, Miss., March 2 to April 28, 1979 28-31. Photographs showing:     28. Housing development in flooded area along Hanging Moss Creek in northern part of Jackson, Miss., April 16, 1979     29. Inundated residential area in the vicinity of Westbrook Road in northern part of Jackson, Miss., April 16, 1979     30. Business district of Jackson, Miss., inundated by Pearl River overflow, April 16, 1979     31. Flooded fairgrounds enclosed by levee, Jackson, Miss., near crest of Pearl River flood, April 16, 1979 32,33. Hydrographs of discharge at selected gaging stations:     32. Pearl River near Monticello, Miss., and near Bogalusa, La., April 1-30, 1979     33. Big Black River at West, Miss., and near Bovina, Miss, April 1-30, 1979 34. Graph showing changes in point velocity, mean velocity, stage, and discharge of Alabama River near Montgomery, Ala, April 13-20, 1979 35-43. Graphs showing velocity distribution and cross sections:     35. Alabama River at U.S. Highway 31 north, near Montgomery, Ala., April 15, 1979     36. Mulberry Creek at highway bridge at Jones, Ala., April 14, 1979     37. Hashuqua Creek near Macon, Miss., April 12, 1979     38. Noxubee River at U.S. Highway 45 bypass near Macon, Miss., April 14, 1979     39. Noxubee River at State Highway 17 near Geiger, Ala., April 15, 1979     40. Tombigbee River at Gainesville, Ala. (main channel), April 15, 1979     41. North River near Samantha, Ala., April 13, 1979     42. Pearl River at Interstate Highway 55 at Jackson, Miss., April 17, 1979     43. Zilpha Creek at State Highway 35 near Kosciusko, Miss., April 12, 1979 44,45. Hydrographs of water levels in observation wells:     44. At Centreville, Ala. (Centreville Gin and Cotton Co.), March-April 1979     45. Near Pickensville, Ala., in the Tombigbee River basin, March-April 1979 46. Map showing location of specific-conductance sampling sites along the Intracoastal Waterway at the mouth of Mobile Bay, April 28-29, 1979 47. Map showing location of flight lines along streams where aerial photographs were obtained on or near the crest of the flood, April 1979 TABLES 1. Supplementary rainfall data, storm of April 11-13, 1979 2. Summary of flood stages and discharges 3. Summary of flood damages on main streams and principal tributaries, March 1979 and April 1979 floods 4. Summary of stages and contents of storage reservoirs 5. Flood-crest stages 6. Streamflow velocities, Alabama River near Montgomery, Ala., April 12-20, 1979 7. Gage height, discharge, and accumulated runoff, flood of April 1979 8. Ground-water levels in selected observation wells in Alabama and Mississippi, April 1979 9. Specific conductance and temperature and samples at selected sites along the Intracoastal Waterway at the mouth of Mobile Bay, April 28-29, 1979 10. Aerial photographs obtained at or near the crest of the flood, April 1979 ABSTRACT A major storm brought large amounts of rainfall over the southeastern United States April 11-13, 1979. Heaviest rain fell over north-central Mississippi and Alabama. Although the storm extended into the head-waters of the Chattahoochee River basin in northwestern Georgia, most flooding there was only moderate. A maximum of 21.5 inches was observed at a site 14 miles southeast of Louisville, Miss. Areal average rainfall exceeded 12 and 8 inches over the upper Pearl and upper Tombigbee River basins, respectively. Owing to a series of antecedent storms in March and April over the Mississippi-Alabama area, soils were saturated and many rivers were already bankfull. Additional rains April 21-23 in Mississippi and April 24-26 in Alabama averaged less than 2 inches over the flooded area. A maximum of 6.4 inches was reported at Ruth, Miss., about 65 miles south of Jackson, where little or no rain fell during the major storm of April 11-13. Floods in Mississippi and Alabama caused by the series of storms were the maximum of record at 60 streamflow gaging stations in the Coosa, Alabama, Tombigbee, Chickasawhay, Pearl, and Big Black River basins. On the Pearl River, peak discharges at main stem gaging stations generally approached or exceeded those of the great flood of 1874, and recurrence intervals generally were greater than 100 years. On some streams, maximum stages and discharges produced by the March 3-4 storm, although greater than those previously observed, were exceeded during the April 11-13 storm. Other storms in April extended the flood duration and added materially to the flood volume. A comparison with the greatest known floods indicates that floods generally one-third greater than those in 1979 may occur in large basins and that floods two or three times greater may occur in small basins. Floods much greater than those observed in April 1979 or than the greatest known floods in the area are likely to occur if the probable maximum precipitation occurs. Nine lives were reported lost. Estimated damages from the March and April flooding totaled nearly $400 million. During April 1979, 75 percent of the total damage occurred in the Pearl River Basin, and 65 percent of the damage occurred in Jackson, Miss., and vicinity. Seventeen thousand people were driven from their homes in Jackson, Miss. The report presents analyses of the meteorological settings of the storms, the distribution of rainfall, and supplementary rainfall data that have not been published elsewhere. It also gives summaries of flood stages and discharges at 221 streamflow gaging stations, stages and contents of 10 reservoirs, flood-crest stages and hydrograph data (gage height, discharge, and accumulated runoff at selected times) at 46 gaging stations, groundwater fluctuations in 11 observation wells, and water salinity and temperature at 22 sites along the Intracoastal Waterway in Mobile Bay. The availability of aerial photography obtained during the flood is summarized, and flood damages are discussed. LizardTech's Djvu plug-in is needed to view these reports. CLICK HERE TO VIEW THE ENTIRE REPORT For questions or comments, contact K. Van Wilson.