FLOODS OF JULY 12, 1972, MARCH 19, 1979, AND JUNE 15, 1991, IN THE TURKEY RIVER BASIN, NORTHEAST IOWA U.S. GEOLOGICAL SURVEY Open-File Report 96-560 Prepared in cooperation with the IOWA HIGHWAY RESEARCH BOARD and the PROJECT DEVELOPMENT DIVISION of the IOWA DEPARTMENT OF TRANSPORTATION (IOWA DOT Research Project HR-140) FLOODS OF JULY 12, 1972, MARCH 19, 1979, AND JUNE 15, 1991, IN THE TURKEY RIVER BASIN, NORTHEAST IOWA By David A. Eash and Barbara A. Koppensteiner U.S. GEOLOGICAL SURVEY Open-File Report 96-560 Prepared in cooperation with the IOWA HIGHWAY RESEARCH BOARD and the PROJECT DEVELOPMENT DIVISION of the IOWA DEPARTMENT OF TRANSPORTATION (IOWA DOT Research Project HR-140) Iowa City, Iowa 1996 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY GORDON P. EATON, Director For additional information Copies of this report can be write to: purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Room 269, Federal Building Branch of Information Services 400 South Clinton Street Box25286,DenverFederalCe~er Iowa City, Iowa 52244 Denver, Colorado 80225-0286 CONTENTS Page Abstract ................................................................................................................................................................................ Introduction .......................................................................................................................................................................... Purpose and scope ...................................................................................................................................................... Acknowledgments....................................................................................................................................................... 1 Study area.............................................................................................................................................................................. 2 Hydrologic data..................................................................................................................................................................... 2 Floodflow frequencies........................................................................................................................................................... 4 Flood history .. .. .. .. ... .. .. .. .. .. ... .. .. ... ... ... ... ... .. .. .. .. .. .. .. .. 5 Flood of February 23, 1922 ............................................................................. :.......................................................... 5 Flood of June 13, 1947................................................................................................................................................ 5 Flood of July 12, 1972 ................................................................................................................................................ 7 Flood of March 19, 1979 ............................................................................................................................................ 7 Flood of June 15, 1991................................................................................................................................................ 7 Flood profile.......................................................................................................................................................................... 10 _Considerations....................................................................................................................................................................... 11 Summary............................................................................................................................................................................... 11 References . .. ... 11 Appendix A. Peak stages and discharges for streamflow-gaging stations in the Turkey River Basin, northeast Iowa, 1902-95 ....................................................................................................................................... ............ 13 Appendix B. Water-surface-elevation profiles for the Turkey River Basin, northeast Iowa................................................ 33 Appendix C. Temporary bench marks and reference points in the Turkey River Basin, northeast Iowa............................. 49 FIGURES 1. Map of the Turkey River Basin showing location of bridge sites used in July 12, 1972, March 19, 1979, and June 15, 1991, flood profiles and U.S. Geological Survey streamflow-gaging stations................................... 3 2. Graph showing water-surface-elevation profiles for the Turkey River, river miles 1.71-117.94 ............................. 35 3. Graphs showing water-surface-elevation profiles for the Turkey River,: 3A. river miles 1.71-15 ........................................................................................................................................... 36 3B. river miles 15-30.............................................................................................................................................. 37 3C. river miles 30-45 .............................................................................................................................................. 38 3D. river miles 45-60.............................................................................................................................................. 39 3E. river miles 60-75 .............................................................................................................................................. 40 3F. river miles 75-90............................................................................................................................................... 41 3G.rivermiles90-105 ............................................................................................................................................ 42 3H. river miles 105-117.94..................................................................................................................................... 43 4. Graph showing water-surface-elevation profiles for the Volga River, river miles 0.42-27.68 ................................. 44 5. Graphs showing water-surface-elevation profiles for the Volga River,: 5A. river miles 0.42-15 ........................................................................................................................................... 45 5B. river miles 15-27.68 ......................................................................................................................................... 46 6. Graph showing water-surface-elevation profiles for Roberts Creek, river miles 0.18-11.27 ................................... 47 7. Graph showing water-surface-elevation profiles for Otter Creek, river miles 0.13-10.16 ....................................... 48 TABLES 1. Floodflow frequencies for streamflow-gaging stations in the Turkey River Basin .................................................. 6 2. Selected flood-peak discharges, recurrence intervals, and unit runoff for streamflow-gaging stations in the Turkey River Basin............................................................................................................................................ 8 CONTENTS iii CONVERSION FACTORS, ABBREVIATIONS, AND VERTICAL DATUM Multiply By To obtain inch (in.) 25.4 millimeter foot (ft) 0.3048 meter mile (mi) 1.609 kilometer square mile (mi 2) 2.590 square kilometer cubic foot per second (ft3/s) 0.02832 cubic meter per second cubic foot per second per 0.01093 cubic meter per second square mile [(ft3/s)/mi2] per square kilometer ton per acre 2.242 megagram per square hectometer Sea Level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929--a geodetic datum derived from a general adjustment of the first-order level nets of the United States and Canada, formerly called Sea Level Datum of 1929. iv FLOODS IN THE TURKEY RIVER BASIN, NORTHEAST IOWA Floods of July 12, 1972, March 19, 1979, and June 15, 1991, in the Turkey River Basin, Northeast Iowa By David A. Eash and Barbara A. Koppensteiner ABSTRACT used by planners and engineers to evaluate the magni­ tude and frequency of floods in a river basin. Water-surface-elevation profiles and peak discharges for the floods of July 12, 1972, March Purpose and Scope 19, 1979, and June 15, 1991, in the Turkey River Basin, northeast Iowa, are presented in this report. The profiles illustrate the 1979 and 1991 floods This report presents water-surface-elevation pro­ files for the floods of July 12, 1972,March 19, 1979, along the Turkey River in Fayette and Clayton and June 15, 1991, in the Turkey River Basin in north­ Counties and along the Volga River in Clayton east Iowa. Profiles for the flood of March 19, 1979, use County; the 1991 flood along Roberts Creek in flood elevations collected by the Iowa Natural Clayton County and along Otter Creek in Fayette Resources Council (1980, p. 12) and are presented in County; and the 1972 flood along the Turkey River this report for comparative purposes. The report pro­ in Winneshiek and Fayette Counties. Water­ vides information on flood stages and discharges, and surface elevations for the flood of March 19, 1979, floodflow frequencies for streamflow-gaging stations were collected by the Iowa Natural Resources in the Turkey River Basin using flood information col­ Council.