DEVELOPMENT OF A FLOOD WARNING NETWORK AND FLOOD-INUNDATION MAPPING IN LICKING COUNTY, OHIO By Chad J. Ostheimer 2012 Scientific Investigations Report 2012-5137 ABSTRACT: Digital flood-inundation maps for selected reaches of South Fork Licking River, Raccoon Creek, North Fork Licking River, and the Licking River in Licking County, Ohio, were created by the U.S. Geological Survey (USGS), in cooperation with the Ohio Department of Transportation; U.S. Department of Transportation, Federal Highway Administration; Muskingum Watershed Conservancy District; U.S. Department of Agriculture, Natural Resources Conservation Service; and the City of Newark and Village of Granville, Ohio. The inundation maps depict estimates of the areal extent of flooding corresponding to water levels (stages) at the following USGS streamgages: South Fork Licking River at Heath, Ohio (03145173); Raccoon Creek below Wilson Street at Newark, Ohio (03145534); North Fork Licking River at East Main Street at Newark, Ohio (03146402); and Licking River near Newark, Ohio (03146500). The maps were provided to the National Weather Service (NWS) for incorporation into a Web-based flood-warning system that can be used in conjunction with NWS flood-forecast data to show areas of predicted flood inundation associated with forecasted flood-peak stages. As part of the flood-warning streamflow network, the USGS re-installed one streamgage on North Fork Licking River, and added three new streamgages, one each on North Fork Licking River, South Fork Licking River, and Raccoon Creek. Additionally, the USGS upgraded a lake-level gage on Buckeye Lake. Data from the streamgages and lake-level gage can be used by emergency-management personnel, in conjunction with the flood-inundation maps, to help determine a course of action when flooding is imminent. Flood profiles for selected reaches were prepared by calibrating steady-state step-backwater models to selected, established streamgage rating curves. The step-backwater models then were used to determine water-surface-elevation profiles for up to 10 flood stages at a streamgage with corresponding streamflows ranging from approximately the 50 to 0.2-percent chance annual-exceedance probabilities for each of the 4 streamgages that correspond to the flood-inundation maps. The computed flood profiles were used in combination with digital elevation data to delineate flood-inundation areas. Maps of Licking County showing flood-inundation areas overlain on digital orthophotographs are presented for the selected floods. The USGS also developed an unsteady-flow model for a reach of South Fork Licking River for use by the NWS to enhance their ability to provide advanced flood warning in the region north of Buckeye Lake, Ohio. The unsteady-flow model was calibrated based on data from four flooding events that occurred from June 2008 to December 2011. Model calibration was approximate due to the fact that there were unmeasured inflows to the river that were not able to be considered during the calibration. Information on unmeasured inflow derived from NWS hydrologic models and additional flood-event data could enable the NWS to further refine the unsteady-flow model. 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. Purpose and Scope Flood-warning systems typically involve major elements including streamflow, lake-level and precipitation networks, hydrologic and hydraulic modeling, flood-inundation mapping, and various means of disseminating the flood-warning information. This study addresses several of those elements including a streamflow and lake-level network, hydraulic modeling, flood-inundation mapping, and Web-based access to the project results. This report describes methods and results of hydrologic and hydraulic analyses of selected streams within Licking County, Ohio, and presents a series of flood-inundation maps developed for selected stages of streamgages located at Licking River near Newark (03146500); North Fork Licking River at East Main Street, Newark (03146402); Raccoon Creek below Wilson Street at Newark (03145534); and South Fork Licking River at Heath (03145173). Tasks specific to this study and discussed in this report are to (1) re-establish one previously discontinued streamgage, install three new streamgages, and upgrade one lake-level gage; (2) develop flood-inundation maps depicting the areal extent of flooding that may occur along each of the studied reaches within Licking County at selected stages and their corresponding streamgages based on steady-state model estimates; and (3) develop a one-dimensional unsteady-flow model for a reach of the South Fork Licking River for use by the NWS. 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 which may be inherent or factored into NWS forecast procedures. The NWS uses river forecast models to estimate the quantity and timing of water flowing through selected river reaches in the United States. These forecast models (1) estimate the amount of runoff generated by a precipitation event, (2) compute how the water will move downstream, and (3) predict the flow and stage (water-surface elevation) for the river at a given location (AHPS forecast point) throughout the forecast period (every six hours over 3 to 5 days). For more information on AHPS forecasts, please see: http://water.weather.gov/ahps/pcpn_and_river_forecasting.pdf A brief description of the contents: readme.txt - this readme document depth_grids - subfolder containing four zipped files (one for each modeled stream) with up to 10 depth grids, one for each flood profile with file extensions: .aux/.rrd polygons - - subfolder containing four zipped files (one for each modeled stream) with up to 10 shapefiles, one for each flood profile with file extensions: .dbf/.prj/.sbn/.bsx/.shp/.shp.xml/.shx LR_Licking_OH.kmz - kmz file for all flood profiles of the Licking River with turn on/off capability using Google Earth software NF_Licking_OH.kmz - kmz file for all flood profiles of North Fork Licking River with turn on/off capability using Google Earth software RC_Licking_OH.kmz - kmz file for all flood profiles of Raccoon Creek with turn on/off capability using Google Earth software SF_Licking_OH.kmz - kmz file for all flood profiles of South Fork Licking River with turn on/off capability using Google Earth software To access the data: The data files can be downloaded via the web from http://pubs.usgs.gov/sir/2012/5137/. The Report and Plates are in Portable Document Format (.pdf) 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 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. Software Required: 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. Any questions regarding this report may be directed to: Chad Ostheimer US Geological Survey, Ohio Water Science Center 6480 Doubletree Avenue Columbus, Ohio 43229 or via e-mail at ostheime@usgs.gov