This data release documents the digital data used to produce flood-inundation maps for a range of gage heights (stages) for the Sabinal River near Utopia, Tex. The simulated flood-inundation maps correspond to a range in stage from 7 to 24 feet (ft) at U.S. Geological Survey (USGS) streamgage 08197970 Sabinal River at Utopia, Tex. at intervals of 0.5-ft. The maps were created for a 10-mile reach of the Sabinal River extending from USGS streamgage 08197936 Sabinal River below Mill Creek near Vanderpool, Tex. to USGS streamgage 08197970 Sabinal River at Utopia, Tex. (hereinafter referred to as the “Utopia gage”) and 7-mile reach of the West Sabinal River were created by the USGS in cooperation with the Bandera County River Authority and Groundwater District and with the Texas Water Development Board. Stage data are collected every 5 minutes and used for estimating areas of inundation near the Utopia gage; the stage data are available from the USGS National Water Information System (NWIS) online database at https://dx.doi.org/10.5066/F7P55KJN (gage information are also directly accessible at https://waterdata.usgs.gov/nwis/). The companion interpretive report (larger work citation) accompanying these digital data is Choi, N., 2023, Flood-inundation maps created using a synthetic rating curve for a 10-mile reach of the Sabinal River and a 7-mile reach of the West Sabinal River near Utopia, Texas, 2021: U.S. Geological Survey Scientific Investigations Report 2023-5001, 18 p., https://doi.org/10.3133/sir20235001. Flood profiles were computed for the stream reach by means of a two-dimensional unsteady state diffusion wave model, Hydrologic Engineering Center's River Analysis System (HEC–RAS; Davidian, 1984; U.S. Army Corps of Engineers, 2016a, b, c). The model results were validated using a synthetic stage-discharge relation at the Utopia gage; the synthetic rating curve was developed based on a regional regression equation by Asquith and others (2013). Detailed information about the methods and data used for this analysis are provided in the companion interpretive report. The flood-inundation maps can be accessed through the Interagency Flood Risk Management Flood Decision Support Toolbox website at https://webapps.usgs.gov/infrm/fdst/.

This data release documents the digital data used to produce flood-inundation maps for a range of gage heights (stages) for the Sabinal River near Utopia, Tex. The simulated flood-inundation maps correspond to a range in stage from 11 to 28 feet (ft) at U.S. Geological Survey (USGS) streamgage 08197970 Sabinal River at Utopia, Tex. at intervals of 0.5-ft. The maps were created for a 10-mile reach of the Sabinal River extending from USGS streamgage 08197936 Sabinal River below Mill Creek near Vanderpool, Tex. to USGS streamgage 08197970 Sabinal River at Utopia, Tex. (hereinafter referred to as the “Utopia gage”) and 7-mile reach of the West Sabinal River were created by the USGS in cooperation with the Bandera County River Authority and Groundwater District and with the Texas Water Development Board. Stage data are collected every 5 minutes and used for estimating areas of inundation near the Utopia gage; the stage data are available from the USGS National Water Information System (NWIS) online database at https://dx.doi.org/10.5066/F7P55KJN (gage information are also directly accessible at https://waterdata.usgs.gov/nwis/). The companion interpretive report (larger work citation) accompanying these digital data is Choi, N., 2023, Flood-inundation maps created using a synthetic rating curve for a 10-mile reach of the Sabinal River and a 7-mile reach of the West Sabinal River near Utopia, Texas, 2021 (ver 2.0, September 2023): U.S. Geological Survey Scientific Investigations Report 2023-5001, 18 p., https://doi.org/10.3133/sir20235001. Flood profiles were computed for the stream reach by means of a two-dimensional unsteady state diffusion wave model, Hydrologic Engineering Center's River Analysis System (HEC–RAS; Davidian, 1984; U.S. Army Corps of Engineers, 2016a, b, c). The model results were validated using a synthetic stage-discharge relation at the Utopia gage; the synthetic rating curve was developed based on a regional regression equation by Asquith and others (2013). Detailed information about the methods and data used for this analysis are provided in the companion interpretive report. The flood-inundation maps can be accessed through the Interagency Flood Risk Management Flood Decision Support Toolbox website at https://webapps.usgs.gov/infrm/fdst/.

Hurricane Harvey made landfall near Rockport, Texas on August 25 as a category 4 hurricane with wind gusts exceeding 150 miles per hour. As Harvey moved inland the forward motion of the storm slowed down and produced tremendous rainfall amounts to southeastern Texas and southwestern Louisiana. Historic flooding occurred in Texas and Louisiana as a result of the widespread, heavy rainfall over an 8-day period in Louisiana in August and September 2017. Following the storm event, U.S. Geological Survey (USGS) hydrographers recovered and documented 2,123 high-water marks in Texas, noting location and height of the water above land surface. Many of these high-water marks were used to create flood-inundation maps for selected communities of Texas that experienced flooding in August and September, 2017. Nineteen flood-inundation maps in 11 river and coastal basins were created by using GIS for areas near rivers that flooded as a result of Harvey in southeastern Texas and southwestern Louisiana. The study area consists of the Brazos, Neches, Pine Island Bayou, Sabine, San Bernard, and San Jacinto River Basins along the coast of the Gulf of Mexico, also including six smaller coastal basins that drain directly to the Gulf of Mexico, and coastal areas from Port Aransas to Matagorda Bay. The HWM elevation data from the USGS Short-tern Network (STN) was used to create the flood water-surface raster file (U.S. Geological Survey [USGS], 2018, Short-Term Network Data Portal: USGS flood information web page, accessed February 13, 2018, at https://water.usgs.gov/floods/FEV.). The water-surface raster was the basis for the creation of the final flood inundation polygon and depth layer to support the development of flood inundation map for the Federal Emergency Management Agency's (FEMA) response and recovery operations.

Hurricane Harvey made landfall near Rockport, Texas on August 25 as a category 4 hurricane with wind gusts exceeding 150 miles per hour. As Harvey moved inland the forward motion of the storm slowed down and produced tremendous rainfall amounts to southeastern Texas and southwestern Louisiana. Historic flooding occurred in Texas and Louisiana as a result of the widespread, heavy rainfall over an 8-day period in Louisiana in August and September 2017. Following the storm event, U.S. Geological Survey (USGS) hydrographers recovered and documented 2,123 high-water marks in Texas, noting location and height of the water above land surface. Many of these high-water marks were used to create flood-inundation maps for selected communities of Texas that experienced flooding in August and September, 2017. Nineteen flood-inundation maps in 11 river and coastal basins were created by using GIS for areas near rivers that flooded as a result of Harvey in southeastern Texas and southwestern Louisiana. The study area consists of the Brazos, Neches, Pine Island Bayou, Sabine, San Bernard, and San Jacinto River Basins along the coast of the Gulf of Mexico, also including six smaller coastal basins that drain directly to the Gulf of Mexico, and coastal areas from Port Aransas to Matagorda Bay. The HWM elevation data from the USGS Short-tern Network (STN) was used to create the flood water-surface raster file (U.S. Geological Survey [USGS], 2018, Short-Term Network Data Portal: USGS flood information web page, accessed February 13, 2018, at https://water.usgs.gov/floods/FEV.). The water-surface raster was the basis for the creation of the final flood inundation polygon and depth layer to support the development of flood inundation map for the Federal Emergency Management Agency's (FEMA) response and recovery operations.

This data release documents the digital data used to produce flood-inundation maps for a range of gage heights (stages) for the Sabinal River near Utopia, Tex. The simulated flood-inundation maps correspond to a range in stage from 7 to 24 feet (ft) at U.S. Geological Survey (USGS) streamgage 08197970 Sabinal River at Utopia, Tex. at intervals of 0.5-ft. The maps were created for a 10-mile reach of the Sabinal River extending from USGS streamgage 08197936 Sabinal River below Mill Creek near Vanderpool, Tex. to USGS streamgage 08197970 Sabinal River at Utopia, Tex. (hereinafter referred to as the “Utopia gage”) and 7-mile reach of the West Sabinal River were created by the USGS in cooperation with the Bandera County River Authority and Groundwater District and with the Texas Water Development Board. Stage data are collected every 5 minutes and used for estimating areas of inundation near the Utopia gage; the stage data are available from the USGS National Water Information System (NWIS) online database at https://dx.doi.org/10.5066/F7P55KJN (gage information are also directly accessible at https://waterdata.usgs.gov/nwis/). The companion interpretive report (larger work citation) accompanying these digital data is Choi, N., 2023, Flood-inundation maps created using a synthetic rating curve for a 10-mile reach of the Sabinal River and a 7-mile reach of the West Sabinal River near Utopia, Texas, 2021: U.S. Geological Survey Scientific Investigations Report 2023–5001, 18 p., https://doi.org/10.3133/sir20235001. Flood profiles were computed for the stream reach by means of a two-dimensional unsteady state diffusion wave model, Hydrologic Engineering Center's River Analysis System (HEC–RAS; Davidian, 1984; U.S. Army Corps of Engineers, 2016a, b, c). The model results were validated using a synthetic stage-discharge relation at the Utopia gage; the synthetic rating curve was developed based on a regional regression equation by Asquith and others (2013). Detailed information about the methods and data used for this analysis are provided in the companion interpretive report. The flood-inundation maps can be accessed through the Interagency Flood Risk Management Flood Decision Support Toolbox website at https://webapps.usgs.gov/infrm/fdst/.

This data release documents the digital data used to produce flood-inundation maps for a range of gage heights (stages) for the Sabinal River near Utopia, Tex. The simulated flood-inundation maps correspond to a range in stage from 11 to 28 feet (ft) at U.S. Geological Survey (USGS) streamgage 08197970 Sabinal River at Utopia, Tex. at intervals of 0.5-ft. The maps were created for a 10-mile reach of the Sabinal River extending from USGS streamgage 08197936 Sabinal River below Mill Creek near Vanderpool, Tex. to USGS streamgage 08197970 Sabinal River at Utopia, Tex. (hereinafter referred to as the “Utopia gage”) and 7-mile reach of the West Sabinal River were created by the USGS in cooperation with the Bandera County River Authority and Groundwater District and with the Texas Water Development Board. Stage data are collected every 5 minutes and used for estimating areas of inundation near the Utopia gage; the stage data are available from the USGS National Water Information System (NWIS) online database at https://dx.doi.org/10.5066/F7P55KJN (gage information are also directly accessible at https://waterdata.usgs.gov/nwis/). The companion interpretive report (larger work citation) accompanying these digital data is Choi, N., 2023, Flood-inundation maps created using a synthetic rating curve for a 10-mile reach of the Sabinal River and a 7-mile reach of the West Sabinal River near Utopia, Texas, 2021 (ver 2.0, September 2023): U.S. Geological Survey Scientific Investigations Report 2023–5001, 18 p., https://doi.org/10.3133/sir20235001. Flood profiles were computed for the stream reach by means of a two-dimensional unsteady state diffusion wave model, Hydrologic Engineering Center's River Analysis System (HEC–RAS; Davidian, 1984; U.S. Army Corps of Engineers, 2016a, b, c). The model results were validated using a synthetic stage-discharge relation at the Utopia gage; the synthetic rating curve was developed based on a regional regression equation by Asquith and others (2013). Detailed information about the methods and data used for this analysis are provided in the companion interpretive report. The flood-inundation maps can be accessed through the Interagency Flood Risk Management Flood Decision Support Toolbox website at https://webapps.usgs.gov/infrm/fdst/.

This data release documents the digital data used to produce flood-inundation maps for a range of gage heights (stages) for the Sabinal River near Utopia, Tex. The simulated flood-inundation maps correspond to a range in stage from 7 to 24 feet (ft) at U.S. Geological Survey (USGS) streamgage 08197970 Sabinal River at Utopia, Tex. at intervals of 0.5-ft. The maps were created for a 10-mile reach of the Sabinal River extending from USGS streamgage 08197936 Sabinal River below Mill Creek near Vanderpool, Tex. to USGS streamgage 08197970 Sabinal River at Utopia, Tex. (hereinafter referred to as the “Utopia gage”) and 7-mile reach of the West Sabinal River were created by the USGS in cooperation with the Bandera County River Authority and Groundwater District and with the Texas Water Development Board. Stage data are collected every 5 minutes and used for estimating areas of inundation near the Utopia gage; the stage data are available from the USGS National Water Information System (NWIS) online database at https://dx.doi.org/10.5066/F7P55KJN (gage information are also directly accessible at https://waterdata.usgs.gov/nwis/). The companion interpretive report (larger work citation) accompanying these digital data is Choi, N., 2023, Flood-inundation maps created using a synthetic rating curve for a 10-mile reach of the Sabinal River and a 7-mile reach of the West Sabinal River near Utopia, Texas, 2021: U.S. Geological Survey Scientific Investigations Report 2023–5001, 18 p., https://doi.org/10.3133/sir20235001. Flood profiles were computed for the stream reach by means of a two-dimensional unsteady state diffusion wave model, Hydrologic Engineering Center's River Analysis System (HEC–RAS; Davidian, 1984; U.S. Army Corps of Engineers, 2016a, b, c). The model results were validated using a synthetic stage-discharge relation at the Utopia gage; the synthetic rating curve was developed based on a regional regression equation by Asquith and others (2013). Detailed information about the methods and data used for this analysis are provided in the companion interpretive report. The flood-inundation maps can be accessed through the Interagency Flood Risk Management Flood Decision Support Toolbox website at https://webapps.usgs.gov/infrm/fdst/.

The development and the generation of the datasets that are published through this data release, were based on the results and findings of the report mentioned here: Kim, M.H., 2018, Flood-inundation maps for the Wabash River at Lafayette, Indiana: U.S. Geological Survey Scientific Investigations Report 2018–5017, 10 p., https://doi.org/10.3133/sir20185017. The geospatial dataset contain final versions of the raster and vector geospatial data and its related metadata, and the model archive dataset contains all relevant files to document and re-run the surface-water (SW) hydraulic model that are discussed in the report.

The development and generation of the datasets that are published in this data release, were based on the methods and findings of the report: Kohn, M.S. and Patton, T.T., 2018, Flood-Inundation Maps for the South Platte River at Fort Morgan, Colorado, 2018: U.S. Geological Survey Scientific Investigations Report 2018-5114, 14 p., https://doi.org/10.3133/sir20185114. The geospatial datasets contain final versions of the raster and vector geospatial data and related metadata, and the model archive dataset contains all relevant files to document and re-run the surface-water hydraulic model that are discussed in the report. Digital flood-inundation maps for a 4.5-mile reach of the South Platte River at Fort Morgan, Colorado from Morgan County Road 16 to Morgan County 20.5, were created by the U.S. Geological Survey (USGS) in cooperation with the Colorado Water Conservation Board. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science web site (https://water.usgs.gov/osw/flood_inundation/), depict estimates of the areal extent and depth of flooding corresponding to select water levels (stages) at USGS streamgage 06759500, South Platte River at Fort Morgan. Current conditions for estimating near-real-time areas of inundation using USGS streamgage information are available through the National Water Information System web interface or the National Weather Service (NWS) Advanced Hydrologic Prediction Service (http:/water.weather.gov/ahps/). Water-profiles were computed for the stream reach by means of a one-dimensional, step-backwater model. The September 15, 2013 and May 20, 2017 floods were used to calibrate the model, and the June 15, 2015 and May 29, 2017 floods were used to independently validate the model. Nine pressure transducers were deployed to record the stage at nine different locations along the reach and to document the floods of May 20 and 29, 2017 at the South Platte River at Fort Morgan streamgage. The calibrated hydraulic model was then used to determine 16 water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from 12 ft (3.66 m) or below bankfull to 27 ft (8.23 m), which is 1 ft (0.3 m) greater than the highest recorded water level (25.73 ft [7.84 m] on September 15, 2013) at the South Platte River at Fort Morgan streamgage during its period of record and the 2013 flood exceeds the major flood stage of 21.5 ft (6.55 m) by more than 4 ft (1.2 m) as defined by the National Weather Service. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from light detection and ranging) to delineate the area flooded at stages ranging from 12-ft to 27-ft. The availability of these inundation maps, along with internet information regarding the current stage from the USGS streamgage 06759500, South Platte River at Fort Morgan, Colorado, and forecast river stages from the NWS Advanced Hydrologic Prediction Service, provides 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.

The development and generation of the datasets that are published through this data release, were based on the results and findings of the report: Kohn, M.S. and Patton, T.T., 2018, Flood-Inundation Maps for the South Platte River at Fort Morgan, Colorado, 2018: U.S. Geological Survey Scientific Investigations Report 2018-5114, 14 p., https://doi.org/10.3133/sir20185114. The geospatial dataset contain final versions of the raster and vector geospatial data and related metadata. The geospatial data include inundation extents, corresponding inundation depths, and the study area boundaries. Digital flood-inundation maps for a 4.5-mile reach of the South Platte River at Fort Morgan, Colorado from Morgan County Road 16 to Morgan County 20.5, were created by the U.S. Geological Survey (USGS) in cooperation with the Colorado Water Conservation Board. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science web site (https://water.usgs.gov/osw/flood_inundation/), depict estimates of the areal extent and depth of flooding corresponding to select water levels (stages) at USGS streamgage 06759500, South Platte River at Fort Morgan. Current conditions for estimating near-real-time areas of inundation using USGS streamgage information are available through the National Water Information System web interface or the National Weather Service (NWS) Advanced Hydrologic Prediction Service (http:/water.weather.gov/ahps/). Water-profiles were computed for the stream reach by means of a one-dimensional, step-backwater model. The September 15, 2013 and May 20, 2017 floods were used to calibrate the model, and the June 15, 2015 and May 29, 2017 floods were used to independently validate the model. Nine pressure transducers were deployed to record the stage at nine different locations along the reach and to document the floods of May 20 and 29, 2017 at the South Platte River at Fort Morgan streamgage. The calibrated hydraulic model was then used to determine 16 water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from 12 ft (3.66 m) or below bankfull to 27 ft (8.23 m), which is 1 ft (0.3 m) greater than the highest recorded water level (25.73 ft [7.84 m] on September 15, 2013) at the South Platte River at Fort Morgan streamgage during its period of record and the 2013 flood exceeds the major flood stage of 21.5 ft (6.55 m) by more than 4 ft (1.2 m) as defined by the National Weather Service. The simulated water-surface profiles were then combined with a geographic information system digital elevation model (derived from light detection and ranging) to delineate the area flooded at stages ranging from 12-ft to 27-ft. The availability of these inundation maps, along with internet information regarding the current stage from the USGS streamgage 06759500, South Platte River at Fort Morgan, Colorado, and forecast river stages from the NWS Advanced Hydrologic Prediction Service, provides 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.