The State of Louisiana experienced widespread flooding during the extreme rainfall events of March and August 2016. The City of Central, Louisiana, which lies above the confluence of the Amite and Comite Rivers, is bordered on the East and West respectively by these rivers. The city had extensive damage from both events, in particular the August 2016 flood in which the river basins received up to 30 inches of documented rainfall. Many streamgages in the area recorded peak of record flood levels from the event. The US Geological Survey (USGS) in cooperation with the City of Central, created a digital flood inundation map library to depict estimated areal extents and depth of flooding along 14.5 and 20.2 mile reach lengths of the Amite and Comite Rivers. The maps were created using a 2-dimensional flow model calibrated to the March and August 2016 events as well as to the current stage-discharge ratings at USGS streamgaging stations 07377300 Amite River at Magnolia, Louisiana and 07378000 Comite River near Comite, Louisiana. The maps range from flood stage to the peak of record stage at the gaging stations. Annual peak flow data was analyzed to determine multiple flooding scenario possibilities between the two gages. This data release provides the ArcGIS files and metadata for these maps. In addition, the maps will be hosted by the USGS on an interactive web mapper accessible to the cooperator and the public at: https://www.usgs.gov/mission-areas/water-resources/science/flood-inundation-mapping-fim-program Use of the maps aids city officials and emergency managers in pre-planning for a flood event in areas such as road and bridge closures, staging of man power and materials, and estimation of affected population. The maps also aid the public in foreseeing their flood risk potential and helps them in their decision making regarding life and property.

Polygon geometry with attributes displaying the 2000 Census tracts and respective population stats in East Baton Rouge Parish, Louisiana.

A slow-moving area of low pressure and a high amount of atmospheric moisture produced heavy rainfall across Louisiana and southwest Mississippi in August 2016. Over 31 inches of rain was reported in Watson, 30 miles northeast of Baton Rouge, over the duration of the event. The result was major flooding that occurred in the southern portions of Louisiana and included areas surrounding Baton Rouge and Lafayette along rivers such as the Amite, Comite, Tangipahoa, Tickfaw, Vermilion, and Mermentau. The U.S. Geological Survey (USGS) Lower Mississippi-Gulf Water Science Center operates many continuous, streamflow-gaging stations in the impacted area. Peak streamflows of record were measured at 10 locations, and seven other locations experienced peak streamflows ranking in the top 5 for the duration of the period of record. In August 2016, USGS personnel made fifty streamflow measurements at 21 locations on streams in Louisiana. Many of those streamflow measurements were made for the purpose of verifying the accuracy of the stage-streamflow relation at the associated gaging station. USGS personnel also recovered and documented 590 high-water marks after the storm event by noting the location and height of the water above land surface. Many of these high water marks were used to create twelve flood-inundation maps for selected communities of Louisiana that experienced flooding in August 2016. This data release provides the actual flood-depth measurements made in selected river basins of Louisiana that were used to produce the flood-inundation maps published in the companion product (Watson and others, 2017). Reference Watson, K.M., Storm, J.B., Breaker, B.K., and Rose, C.E., 2017, Characterization of peak streamflows and flood inundation of selected areas in Louisiana from the August 2016 flood: U.S. Geological Survey Scientific Investigations Report 2017–5005, 26 p., https://doi.org/10.3133/sir20175005.

Digital flood-inundation maps for a 9.9-mile reach of Dardenne Creek, St. Charles County, Missouri, were created by the U.S. Geological Survey (USGS) in cooperation with St. Charles County, Missouri Department of Transportation, and the cities of O'Fallon and St. Peters, Missouri. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Program at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to select water levels (stages) at the USGS streamgages 05514860 Dardenne Creek at Old Town St. Peters, Missouri, and 05587450 Mississippi River at Grafton, Illinois. Near-real-time stages at these streamgages may be obtained from the USGS National Water Information System database at https://doi.org/10.5066/F7P55KJN or the National Weather Service Advanced Hydrologic Prediction Service at https://water.weather.gov/ahps2/hydrograph.php?wfo=lsx&gage=drcm7 (USGS streamgage 05514860) and https://water.weather.gov/ahps2/hydrograph.php?wfo=lsx&gage=grfi2 (USGS streamgage 05587450), which also forecasts flood hydrographs at these sites. Flood profiles were computed for the Dardenne Creek stream reach by means of a one-dimensional model for simulation of water-surface profiles with steady-state flow computations. The model was calibrated using the current stage-discharge relation at the USGS streamgages 05514840 Dardenne Creek at O’Fallon, Missouri, and 05514860 Dardenne Creek at St. Peters, Missouri, and documented high-water marks from the flood of December 2015. The hydraulic model was then used to compute 16 water-surface profiles for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from 16 ft (near bankfull) to 32 ft, at the USGS streamgage 05514860 Dardenne Creek at Old Town St. Peters, Missouri. The upper stage for each map library exceeds the stage corresponding to the estimated 0.2-percent annual exceedance probability flood (500-year recurrence interval flood) at the streamgage locations. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from light detection and ranging (lidar) data having a 0.26-ft vertical accuracy and 0.71-ft horizontal resolution) to delineate the area flooded at each water level. The availability of these maps, along with information regarding current stage from the USGS streamgages and forecasted high-flow stages from the National Weather Service, will provide emergency management personnel and residents with information that is critical for flood mitigation, preparedness and planning, flood-response activities such as evacuations and road closures, as well as for post-flood recovery efforts. The data are provided in the Environmental Systems Research Institute (ESRI) shapefile format compressed into a zip archive that is named DardenneCr_shapefile.zip. The data are provided in the Environmental Systems Research Institute (ESRI) shapefile format compressed into a zip archive that is named DardenneCr_shapefile.zip.