The 1993 Flood on the Mississippi River in Illinois by Nani G. Bhowmik, Scientific Editor and Coordinator Andrew G. Buck Stanley A. Changnon Robert H. Dalton Ali Durgunoglu Misganaw Demissie Arlan R. Juhl H. Vernon Knapp Kenneth E. Kunkel Sally A. McConkey Robert W. Scott Krishan P. Singh Ta-Wei David Soong Richard E. Sparks Adrian P. Visocky Donald R. Vonnahme Wayne M. Wendland Illinois State Water Survey Miscellaneous Publication 151 The 1993 Flood on the Mississippi River JULY 4, 1988 JULY 18, 1993 Counterclockwise from top to bottom - Confluence of the Illinois, Mississippi, and Missouri Rivers (Landsat imagery courtesy of the Earth Observation Satellite Company, Lanham, Maryland) Metric Conversions 1 foot = 0.305 meter 1 mile = 1.61 kilometers 1 square mile = 2.590 square kilometers 1 cubic foot per second = 28.32 cubic decimeters per second 1 inch = 2.54 centimeters First Printing January 1994 Second Printing January 1995 This second printing was made possible by a grant from the National Biological Survey, Environmental Management Technical Center, Onalaska,WI, with Bob Delaney as Program Director. Printed on recycled and recyclable papers using soybean oil ink. 1.5M-84479-1/95 The 1993 Flood on the Mississippi River in Illinois by Nani G. Bhowmik, Scientific Editor and Coordinator, Illinois State Water Survey Andrew G. Buck, Illinois State Water Survey Stanley A. Changnon, Illinois State Water Survey Robert H. Dalton, Illinois Department of Transportation/Division of Water Resources Ali Durgunoglu, Illinois State Water Survey Misganaw Demissie, Illinois State Water Survey Arlan R. Juhl, Illinois Department of Transportation/Division of Water Resources H. Vernon Knapp, Illinois State Water Survey Kenneth E. Kunkel, Illinois State Water Survey Sally A. McConkey, Illinois State Water Survey Robert W. Scott, Illinois State Water Survey Krishan P. Singh, Illinois State Water Survey Ta-Wei David Soong, Illinois State Water Survey Richard E. Sparks, Illinois Natural History Survey Adrian P. Visocky, Illinois State Water Survey Donald R. Vonnahme, Illinois Department of Transportation/Division of Water Resources Wayne M. Wendland, Illinois State Water Survey Title: The 1993 Flood on the Mississippi River in Illinois. Abstract: This report on the 1993 flood on the Mississippi River in Illinois and on the lower reaches of the Illinois River was prepared by the Illinois State Water Survey with assistance from the Illinois Department of Transportation/Division of Water Resources and the Illinois Natural History Survey. The report begins with a brief description of the physical setting of the Upper Mississippi River System, including historical facts on climate, precipitation, hydrology, and floods. The 1993 flood is discussed with regard to precipitation, soil moisture, stages, flows, levee breaches, and discharge through levee breaches. Also discussed are impacts of the flood on social, economic, hydraulic and hydrologic, and environmental aspects of the river and its residents. Impacts on water quality, the environment, and public water supplies, including the beneficial and detrimental aspects of the flood, are also included. The lessons learned from this flood focus on the performance of the levees, governmental responses, the effects of flood fighting, change in stages due to levee breaches, flood modeling, and the lack of information dissemination to the public on the technical aspects of the flood. These lessons point out information gaps and the need for research in the areas of hydraulics and hydrology, meteorology, sediment transport and sedimentation, surface and ground-water interactions, water quality, and levees. The report presents a comprehensive summary of the 1993 flood as far as climate, hydrology, and hydraulics are concerned. Reference: Bhowmik, N.G., et al., The 1993 Flood on the Mississippi River in Illinois, Illinois State Water Survey, Champaign, Miscellaneous Publication 151. Indexing Terms: Flood, Mississippi River, Illinois River, 1993 flood, levees, flood flow, stages, climate, precipitation, soil moisture, flood damage, ground water. CONTENTS l. INTRODUCTION ................................................................................................................................... 1 Acknowledgments . ..................................................................................................................................... 2 2. BACKGROUND.. ................................................................................................................................ 3 Physical Setting .......................................................................................................................................... 3 UMR l: Head of Navigation to L&D 10 ......................................................................................... 6 UMR 2: L&D 10 to L&D 19 ......................................................................................................... 6 UMR 3: L&D 19 to L&D 26 ......................................................................................................... 8 UMR 4: L&D 26 to Cairo, The Middle River ................................................................................ 8 Climate of the Mississippi River Watershed ................................................................................................ 8 Hydrology of the Upper Mississippi River ............................................................................................... 10 Average Runoff ......................................................................................................................... 10 Trends in Runoff ......................................................................................................................... 10 Possible Causes of Increased Flows ............................................................................................ 17 Flooding .................................................................................................................................... 17 Flooding Magnitude.. ................................................................................................................. 20 Historical Floods and Stages ...................................................................................................... 20 Historical Background of the Levees ........................................................................................................ 24 Illinois Drainage and Levee Districts along the Mississippi River ............................................... 25 Drainage and Levee Districts along the Alton Pool of the Illinois River ...................................... 25 Levee Design, Construction, and Failure .................................................................................................. 30 Levee Design ............................................................................................................................. 30 Levee Construction .................................................................................................................... 33 Levee Failure ............................................................................................................................. 33 3. THE 1993 FLOOD ............................................................................................................................. 37 Synoptic Basis for the Flood of 1993 ....................................................................................................... 37 Precipitation Patterns ............................................................................................................................... 39 Precipitation in Early 1993 ......................................................................................................... 39 Precipitation, April through September 1993 .............................................................................. 43 Return Frequencies of Rainfall Events, Summer 1993 ................................................................ 43 Days with Principal Rainfall Amounts, June and July 1993 ......................................................... 44 Mean Statewide Precipitation, June 1993 .................................................................................... 44 Mean Statewide Precipitation, July 1993 .................................................................................... 46 Mean Statewide Precipitation, August and September 1993 ........................................................ 47 Rainfall within Major Watersheds of the Region ........................................................................ 47 Soil Moisture, Summer 1993 ................................................................................................................... 50 Soil Moisture Outlook for Fall and Winter Conditions .............................................................................. 52 Chronology of the Flood .......................................................................................................................... 56 Hydrologic Conditions Preceding the 1993 Flood ....................................................................... 56 June Flooding in Minnesota and Wisconsin ................................................................................ 57 July Flooding in Iowa and the Mississippi River Upstream of St. Louis ...................................... 58 Flooding in the Missouri River Watershed and the