FLOOD-INUNDATION MAPS FOR THE WHITE RIVER AT SPENCER, INDIANA By Elizabeth A. Nystrom, 2013 U.S. Geological Survey Scientific Investigations Map 3251 ABSTRACT: Digital flood-inundation maps for a 5.3-mile reach of the White River at Spencer, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage White River at Spencer, Indiana (sta. no. 03357000). Current conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/. NWS-forecasted peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated by using the most current stage-discharge relation at the White River at Spencer, Indiana, streamgage and documented high-water marks from the flood of June 8, 2008. The hydraulic model was then used to compute 20 water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from the National Weather Service (NWS) action stage (9 feet) to the highest rated stage (28 feet) at the streamgage. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from Light Detection and Ranging (LiDAR) data) in order to delineate the area flooded at each water level. The availability of these maps along with Internet information regarding the current stage from the Spencer USGS streamgage and forecasted stream stages from the NWS will provide emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures, as well as for post-flood recovery efforts. DISCLAIMERS: This data base, identified as SIM 3251, has been approved for release and publication by the Director of the U.S. Geological Survey. Although this database has been subjected to rigorous review and is substantially complete, the U.S. Geological Survey reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the U.S. geological Survey nor the U.S. Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other System, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein. 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 information product, for the most part, is in the public domain, it also contains copyrighted materials as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. Disclaimer for Flood-Inundation Maps: Inundated areas shown should not be used for navigation, regulatory, permitting, or other legal purposes. The USGS provides these maps “as-is” for a quick reference, emergency planning tool but assumes no legal liability or responsibility resulting from the use of this information. Uncertainties and Limitations for Use of Flood-Inundation Maps: Although the flood-inundation maps represent the boundaries of inundated areas with a distinct line, some uncertainty is associated with these maps. The flood boundaries shown were estimated based on water stages (water-surface elevations) and streamflows at USGS streamgage 03357000 White River at Spencer, Ind. Water-surface elevations along the stream reaches were estimated by steady-state hydraulic modeling, assuming unobstructed flow, and using streamflows and hydrologic conditions anticipated at the USGS streamgage(s). The hydraulic model reflects the land-cover characteristics and any bridge, dam, levee, or other hydraulic structures existing as of November 2011. Unique meteorological factors (timing and distribution of precipitation) may cause actual streamflows along the modeled reach to vary from those assumed during a flood, which may lead to deviations in the water-surface elevations and inundation boundaries shown. Additional areas may be flooded due to unanticipated conditions such as: changes in the streambed elevation or roughness, backwater into major tributaries along a main stem river, or backwater from localized debris or ice jams. The accuracy of the floodwater extent portrayed on these maps will vary with the accuracy of the digital elevation model used to simulate the land surface. Additional uncertainties and limitations pertinent to this study may be dscribed elsewhere in this report. If this series of flood-inundation maps will be used in conjunction with National Weather Service (NWS) river forecasts, the user should be aware of additional uncertainties that may be inherent or factored into NWS forecast procedures. The NWS uses forecast models to estimate the quantity and timing of water flowing through selected stream reaches in the United States. These forecast models (1) estimate the amount of runoff generated by precipitation and snowmelt, (2) simulate the movement of floodwater as it proceeds downstream, and (3) predict the flow and stage (water-surface elevation) for the stream at a given location (AHPS forecast point) throughout the forecast period (every 6 hours and 3 to 5 days out in many locations). For more information on AHPS forecasts, please see: http://water.weather.gov/ahps/pcpn_and_river_forecasting.pdf. CONTENTS: This report consists of a pamphlet and 20 map sheets. The single metadata file pertains to all of the maps and the shapefile. 00Readme.txt SIM3251_pamphlet.pdf SIM3251_dep_grd_metadata.xml SIM3251_shp_metadata.xml Datafiles depth_grids.zip shapefile.zip The shapefile is as follows: shapefile.zip SpenIN.shp (.dbf/.prj/.sbn/.sbx/.shp.xml/.shx) map_sheets map_sheets.zip (sheets 1 through 13 in .pdf format) sheet01_534.63_sim3251.pdf sheet02_535.63_sim3251.pdf sheet03_536.63_sim3251.pdf sheet04_537.63_sim3251.pdf sheet05_538.63_sim3251.pdf Sheet06_539.63_sim3251.pdf sheet07_540.63_sim3251.pdf sheet08_541.63_sim3251.pdf sheet09_542.63_sim3251.pdf sheet10_543.63_sim3251.pdf sheet11_544.63_sim3251.pdf sheet12_545.63_sim3251.pdf sheet13_546.63_sim3251.pdf sheet14_547.63_sim3251.pdf sheet15_548.63_sim3251.pdf Sheet16_549.63_sim3251.pdf sheet17_550.63_sim3251.pdf sheet18_551.63_sim3251.pdf sheet19_552.63_sim3251.pdf sheet20_553.63_sim3251.pdf A low-resolution version of the maps is also available: map_sheets_jpg map_sheets_jpg.zip sheet01_534.63_SIM3251.jpg Sheet02_535.63_sim3251.jpg Sheet03_536.63_sim3251.jpg Sheet04_537.63_sim3251.jpg Sheet05_538.63_sim3251.jpg Sheet06_539.63_sim3251.jpg Sheet07_540.63_sim3251.jpg Sheet08_541.63_sim3251.jpg Sheet09_542.63_sim3251.jpg Sheet10_543.63_sim3251.jpg Sheet11_544.63_sim3251.jpg Sheet12_545.63_sim3251.jpg Sheet13_546.63_sim3251.jpg Sheet14_547.63_sim3251.jpg Sheet15_548.63_sim3251.jpg Sheet16_549.63_sim3251.jpg Sheet17_550.63_sim3251.jpg Sheet18_551.63_sim3251.jpg Sheet19_552.63_sim3251.jpg Sheet20_553.63_sim3251.jpg INSTRUCTIONS AND DOCUMENTATION FOR U.S. GEOLOGICAL SURVEY SCIENTIFIC INVESTIGATIONS MAP 3251 To access the data: The data files can be downloaded via the web from http://pubs.usgs.gov/sim/3251.The main product is a Portable Document Format (.pdf) map and pamphlet which requires Adobe Acrobat for viewing. Acrobat software runs on a variety of systems, and is available for download free of charge from Adobe at http://www.adobe.com. Software preferred: Adobe Acrobat (6.x, 7.x, or 8.x), or Adobe Acrobat Pro (6.x, 7.x, or 8.x), or the free Adobe Reader (6.x, 7.x, or 8.x), 8.x is preferred.ArcGIS 9.3 preferred, older versions may also work. ArcReader may be downloaded free of charge from http://www.esri.com/software/arcgis/arcreader/download.htm for viewing additional files included in this report.