Flood of January 19-20, 1996 in New York State
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Flood of January 19-20, 1996 in New York State By Richard Lumia U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 97-4252 Prepared in cooperation with the IISRS New York State Department of Transportation science for a changing world Albany, New York 1998 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Thomas J. Casadevall, Acting Director The use of trade, product, or firm names in this report is for identification or location purposes only and does not constitute endorsement of products by the U.S. Geological Survey, nor impute responsibility for any present or potential effects on the natural resources of the United States. For addtional information write to: Copies of this report can be purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Branch of Information Services 425 Jordan Road Box 25286 Troy, New York 12180 Denver, CO 80225-0286 CONTENTS Page Abstract....................................................................................... 1 Introduction.................................................................................... 1 Purpose and Scope ......................................................................... 2 Acknowledgments ......................................................................... 3 Physiography and Climate of New York and the Catskill Mountain Region .................................. 4 Physiography.............................................................................. 4 Climate .................................................................................. 8 Storm and Floods of January 19-20, 1996 ............................................................ 8 Antecedent Conditions ...................................................................... 8 Precipitation .............................................................................. 9 Flooding ................................................................................. 10 Flood Discharge and Frequency .......................................................... 13 Storm Runoff ........................................................................ 17 Effect of Reservoirs ................................................................... 26 Flood Profiles of Schoharie Creek ........................................................ 34 Summary ...................................................................................... 45 References Cited ................................................................................ 45 FIGURES 1-3. Maps of New York showing: 1 A. Major drainage basins, and Federal disaster areas after the flooding of January 19-20, 1996 ........ 2 B. Selected geographic features .......................................................... 3 2. Lines of equal precipitation from the storm of January 18-19, 1996 ............................. 5 3. Lines of equal snow depth on January 15, 1996 ............................................. 6 4. Map showing major geographic features of the Catskill Mountain region in southeastern New York. ...... 7 5-7. Graphs showing: 5. Daily mean discharges of two Catskill Mountain streams from October 1995 through January 1996, in relation to daily mean flows exceeded 20, 50, and 80 percent of the time ........... 9 6. Rainfall and runoff at Claryville, N.Y, during the storm of January 18-20, 1996 ................... 11 7. Snow depth, maximum air temperature and rainfall data from six selected National Weather Service stations, January 1996............................................. 12 8. Map of New York showing lines of equal water equivalent of snowpack on January 16, 1996 ............ 13 9. Photographs showing: A. Washout on Chase Brook Road across Chase Brook near Cannonsville Reservoir in Delaware County, N.Y, on January 19, 1996 ........................................................ 14 B. Fair Street bridge over the East Branch Delaware River at Margaretville, N.Y, after the flood of January 19, 1996 ................................................................... 15 C. West Branch Delaware River overflow at Delaware Street in Walton, N.Y. on January 19, 1996 ........ 16 D. Covered bridge over Schoharie Creek in North Blenheim, N.Y, with the height of the January 19, 1996 and April 1987 floods ................................................................. 17 10. Map of New York showing locations of streamflow gaging stations and peak-discharge recurrence intervals for the floods of January 19-20, 1996 ....................................................... 18-19 11. Graphs showing annual peak discharges through 1996, and discharges of 10-, 50-, and 100-year recurrence intervals, for 16 selected gaging stations ..................................................... 20-23 Contents III 12. Graphs showing peak discharge as a function of drainage area during the flood of January 19-20, 1996 at sites within the Catskill Mountain region: A. Sites within Schoharie Creek basin........................................................ 24 B. Sites within Hudson River, Esopus, Rondout, and Catskill Creek basins. .......................... 24 C. Sites within East Branch Delaware River basin .............................................. 24 D. Sites within West Branch Delaware River basin.............................................. 24 E. Sites within Neversink River basin ........................................................ 25 F. Sites on Delaware River................................................................. 25 G. All sites within Catskill Mountain region ................................................... 25 H. All sites in New York State .............................................................. 25 13. Graph showing peak discharge as a function of drainage area for sites on Schoharie Creek during the flood of January 19-20, 1996 ......................................... 26 14. Map of New York showing lines of equal storm runoff for January 18-23, 1996 ........................ 27 15. Discharge hydrographs of the January 1996 flood, the previous maximum flood, and the April 1987 flood, at six continuous-record streamflow gaging stations in the Catskill Mountain region of New York..................................................... 28 16. Discharge hydrographs for selected gaging stations in the Catskill Mountain region, N.Y, January 18-21, 1996: A. West Branch, East Branch, and main stem of the Delaware River................................ 29 B. Schoharie Creek ...................................................................... 29 17. Hydrographs of daily inflow, outflow, and lake or reservoir water-surface elevation for selected sites in New York for January 15-31, 1996 ........................................... 31-33 18. Graphs showing inflows to Cannonsville and Pepacton Reservoirs during January 19-21, 1996: A. Cannonsville Reservoir ................................................................ 34 B. Pepacton Reservoir.................................................................... 34 19. Profile of Schoharie Creek showing locations of major communities, USGS gaging stations, dams, and January 1996 floodmarks. ............................................ 35 20. Map of Schoharie Creek basin showing locations of streamflow-gaging stations and major geographic features along Schoharie Creek. ............................................................. 36 21. Water-surface profiles of Schoharie Creek during the flood of January 19-20, 1996 ..................... 37-44 TABLES 1. Disaster assistance, for Counties of New York, following the floods of January 19-20, 1996 ............... 4 2. Storage above minimum operating level in the New York City reservoir system, October 1995 through January 1996 .......................................................... 10 3. Maximum rainfall for selected durations recorded at the Claryville, N.Y. weather station during January 18-19, 1996 ................................................................. 10 4. Rainfall frequency relations for storms of 3-, 6-, 12-, and 24-hour duration at Claryville, N.Y. ............. 11 5. Peak stages and discharges for the New York floods of January 19-20, 1996............................ 47-61 6. Data on selected lakes and reservoirs in New York during the runoff period of the January 1996 storm ....... 30 IV Contents CONVERSION FACTORS AND VERTICAL DATUM Multiply By To obtain Length inch (in.) 25.4 millimeter foot (ft) 0.3048 meter mile (mi) 1.609 kilometer Area square mile (mi2) 2.590 square kilometer Volume cubic foot (ft3) 0.02832 cubic meter million gallons (Mgal) 3,785 cubic meter billion gallons (Bgal) 3.785x 106 cubic meter Flow rate cubic foot per second (ft-Vs) 0.02832 cubic meter per second cubic foot per second per square mile [(ft3/s)/mi2] 0.01093 cubic meter per second per square kilometer Air Temperature degrees Fahrenheit (° F) 0 C=5/9 (° F -32) degrees Celsius (° C) Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929) a geodetic datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929. Contents Flood of January 19-20,1996 in New York State by Richard Lumia ABSTRACT INTRODUCTION Heavy rain during January 18-19, 1996, Precipitation from a strong storm during January combined with unseasonably warm temperatures 18-20, 1996, combined with unseasonably warm that caused rapid snowmelt, resulted in wide temperatures that