FLOOD-INUNDATION MAPS FOR THE DUPAGE RIVER FROM PLAINFIELD TO SHOREWOOD, ILLINOIS, 2013 By Elizabeth A. Murphy and Jennifer B. Sharpe 2013 U.S. Geological Survey Scientific Investigations Map 3275 ABSTRACT: Digital flood-inundation maps for a 15.5-mi reach of the DuPage River from Plainfield to Shorewood, Illinois, were created by the U.S. Geological Survey (USGS) in cooperation with the Will County Stormwater Management Planning Committee. 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 of flooding corresponding to selected water levels (gage heights or stages) at the USGS streamgage at DuPage River at Shorewood, Illinois (sta. no. 05540500). Current conditions at the USGS streamgage may be obtained on the Internet at http://waterdata.usgs.gov/usa/nwis/uv?05540500. In addition, the information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that are often co-located at USGS streamgages. The NWS forecasted peak-stage information, also shown on the DuPage River at Shorewood inundation Web site, 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 hydraulic model was then used to determine nine water-surface profiles for flood stages at 1-ft intervals referenced to the streamgage datum and ranging from NWS Action stage of 6 ft to the historic crest of 14.0 ft. The simulated water-surface profiles were then combined with a Digital Elevation Model (DEM) (derived from Light Detection And Ranging (LiDAR) data) by using a Geographic Information System (GIS) in order to delineate the area flooded at each water level. These maps, along with information on the Internet regarding current gage height from USGS streamgages and forecasted stream stages from the NWS, 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: 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. 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.This data base, identified as SIM 3275, 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.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. 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 on the basis of gage heights (water-surface elevations) and streamflows (discharges) at a selected USGS streamgage. 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. The hydraulic model reflects the land-cover characteristics and any bridge, dam, levee, or other hydraulic structures existing in 2010. 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 described 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: 00Readme.txt SIM3275.pdf SIM3275_metadata.met SIM3275_map_sheets.zip (sheets 1 through 7 in .pdf format) datafiles: This report consists of a report with 9 map sheets, each sheet has data files, and the single metadata file pertains to all of the maps. SIM3275_Shapefiles.zip The shapefiles are as follows: 05540500_6.shp (.dbf/.prj/.sbn/.sbx/.shx) 05540500_7.shp (.dbf/.prj/.sbn/.sbx/.shx) 05540500_8.shp (.dbf/.prj/.sbn/.sbx/.shx) 05540500_9.shp (.dbf/.prj/.sbn/.sbx/.shx) 05540500_10.shp (.dbf/.prj/.sbn/.sbx/.shx) 05540500_11.shp (.dbf/.prj/.sbn/.sbx/.shx) 05540500_12.shp (.dbf/.prj/.sbn/.sbx/.shx) 05540500_13.shp (.dbf/.prj/.sbn/.sbx/.shx) 05540500_14.shp (.dbf/.prj/.sbn/.sbx/.shx) study_extents.shp (.dbf/.prj/.sbn/.sbx/.shx) SIM3275_Grids.zip The depth grids are as follows: depth_grid6 depth_grid7 depth_grid8 depth_grid9 depth_grid10 depth_grid11 depth_grid12 depth_grid13 depth_grid14 SIM3275_kmz (folder) VI. INSTRUCTIONS AND DOCUMENTATION FOR U.S. GEOLOGICAL SURVEY SCIENTIFIC INVESTIGATIONS MAP 3275 To access the data: The data files can be downloaded via the web from http://pubs.usgs.gov/sim/3275.The main product is a Portable Document Format (.pdf) report 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. To access the .kmz files in this report, download and install Google Earth free of charge at http://www.google.com/earth/index.htm. Launch Google Earth, click the file menu and choose open. Locate and select the .kmz file on your computer. References to non-U.S. Department of the Interior (DOI) products do not constitute an endorsement by the DOI. By viewing the Google Maps API on this web site the user agrees to these terms(terms found at: http://code.google.com/apis/maps/terms.html) of Service set forth by Google. Software Recommended: 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 10.0 preferred, older versions may also work.