Flood Plain Delineation for the Fremont River and Bull Creek, Hanksville, Utah Prepared in cooperation with US Army Corps of Engineers ® Scientific Investigations Report 2008–5233 U.S. Department of the Interior U.S. Geological Survey Cover photo: Looking upstream, view of Fremont River north of Hanksville, Utah. Source: Terry Kenney, USGS, 2007. Flood Plain Delineation for the Fremont River and Bull Creek, Hanksville, Utah By Terry A. Kenney and Susan G. Buto US Army Corps of Engineers ® Scientific Investigations Report 2008–5233 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DIRK KEMPTHORNE, Secretary U.S. Geological Survey Mark D. Myers, Director U.S. Geological Survey, Reston, Virginia: 2008 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS--the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Kenney, T.A., and Buto, S.G., 2008, Flood plain delineation for the Fremont River and Bull Creek, Hanksville, Utah: U.S. Geological Survey Scientific Investigations Report 2008-5233, 28 p. Available at http://pubs.usgs.gov/sir/2008/5233 iii Contents Abstract ......................................................................................................................................................... 1 Introduction ................................................................................................................................................... 1 Purpose and Scope ............................................................................................................................. 1 Description of Study Area .................................................................................................................. 1 Flood Plain Delineation ............................................................................................................................... 6 Hydrologic Analyses ........................................................................................................................... 6 Fremont River .............................................................................................................................. 6 Bull Creek .................................................................................................................................... 8 Hydraulic Analyses ........................................................................................................................... 10 Data Acquisition and Processing Methods ......................................................................... 10 Fremont River ............................................................................................................................ 10 Bull Creek .................................................................................................................................. 13 Determination of Roughness Characteristics ...................................................................... 13 Results .......................................................................................................................................................... 13 Fremont River ..................................................................................................................................... 13 Bull Creek ........................................................................................................................................... 15 Model Limitations .............................................................................................................................. 21 Summary ...................................................................................................................................................... 22 References Cited ........................................................................................................................................ 22 Appendix A .................................................................................................................................................. 24 Appendix B .................................................................................................................................................. 25 Supplemental Map ..................................................................................................................................... 26 Figures 1. Map showing location of Fremont River and Bull Creek study reaches near Hanksville, Utah .......................................................................................................................... 2 2. Photographs of observed banks on the edge of the Fremont River flood plain, Utah ............................................................................................................................................... 4 3. Photograph of upstream view of Bull Creek south of Hanksville, Utah, near cross- section 11 ...................................................................................................................................... 7 4. Photograph of downstream view of Bull Creek south of Hanksville, Utah, near cross-section 8 .................................................................................................................. 7 5. Map showing individual survey data points for the Fremont River and Bull Creek study reaches, Utah ................................................................................................................. 11 6. Map showing reach characteristics and cross-sections that were input into HEC-RAS for the Fremont River study reach, Utah ............................................................. 12 7. Map showing predicted inundation associated with the 1 percent chance peak streamflow for the Fremont River study reach, Utah .......................................................... 16 8. Map showing predicted inundation associated with the 1 percent chance peak streamflow for the Bull Creek study reach, Utah ................................................................ 17 9. Graph showing predicted water-surface elevation profile for the 1 percent chance peak stream-flow for the Fremont River study reach, Utah ................................ 19 iv 10. Graph showing predicted water-surface elevation profile for the 1 percent chance peak stream-flow for the Bull Creek study reach, Utah ...................................... 20 11. Photograph of 100 South Bridge in Bull Creek, Utah .......................................................... 20 12. Photograph of Main Street culvert in Bull Creek, Utah ...................................................... 21 Tables 1. Annual (water year, October–September) peak streamflows for USGS streamflow- gaging stations 09330400, Fremont River near Hanksville, Utah, and 09333500 Dirty Devil River above Poison Spring near Hanksville, Utah ....................................................... 3 2. Annual (water year, October–September) peak streamflows for USGS streamflow gaging stations 09330410, Bull Creek near Hanksville, Utah, and 09329050, Seven Mile Creek near Fish Lake, Utah .............................................................................................. 9 3. Manning’s roughness coefficients and predicted water-surface elevations for Fremont River study reach, Utah ............................................................................................ 14 4. Manning’s roughness coefficients and predicted water-surface elevations for Bull Creek study reach, Utah .................................................................................................. 15 5. Predicted hydraulic parameters for cross-sections of the Fremont River study reach, Utah ................................................................................................................................ 18 6. Predicted hydraulic parameters for cross-sections of Bull Creek study reach ............ 19 v Conversion Factors and Datums Multiply By To obtain Length foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) Area square mile (mi2) 2.590 square kilometer (km2) Flow rate cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s) Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88). Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83). vi Acronyms Used in the Text (Clarification or additional information given in parentheses) DEM Digital Elevation Model ESRI Environmental Systems Research Institute FPMS Flood Plain Management Services (USACE) GIS geographic information system HEC-RAS Hydrologic Engineering Center River Analysis System MD_SWMS Multi-Dimensional Surface Water Modeling System (USGS) NED National Elevation Dataset (USGS) NGS National Geodetic Survey NSRS National Spatial Reference System OPUS Online Positioning User Service RTK-GPS real-time kinematic global positioning system SAM Slope Area Measurement USACE U.S. Army Corps of Engineers USGS