AtkinsRealis USA, Inc. 20241231 Version 2.7.5.6 FEMA-DCS-Terrain Washington, DC Federal Emergency Management Agency http://hazards.fema.gov Federal Emergency Management Agency 20241231 Terrain data, as defined in FEMAs Guidelines and Standards for Flood Risk Analysis and Mapping, describe the digital topographic data that were used to create the elevation data representing the terrain environment of a watershed and/or floodplain. Terrain data requirements allow for flexibility in the types of information used to produce final terrain deliverables. Submission of the terrain data sources allows FEMA to account for the origins of the flood study elevation data. (Source: FEMA Guidelines and Standards for Flood Risk Analysis and Mapping.) Terrain data are used to represent the topography of a watershed and/or floodplain environment and to extract useful information for hydraulic and hydrologic models. (Source: FEMA Guidelines and Standards for Flood Risk Analysis and Mapping) 20241231 MIP Submission Date In work Unknown -99.688522 -95.452095 33.874994 26.962241 ISO 19115 Topic Category elevation FEMA NFIP Topic Category Land Surface Relief Topography Digital Elevation Model Elevation Data Slope LIDAR Breaklines Contours DEM Flow Vectors Bare Earth TIN Triangulated Irregular Network Hydro Enforced DEM None REGION 6 STATE TX COUNTY BLANCO COUNTY-FIPS 48031 COUNTY BURNET COUNTY-FIPS 48053 COMMUNITY CITY OF BURNET FEMA-CID 480092 COMMUNITY CITY OF COTTONWOOD SHORES FEMA-CID 481614 COMMUNITY CITY OF MARBLE FALLS FEMA-CID 480093 COMMUNITY CITY OF MEADOWLAKES FEMA-CID 481613 SPICEWOOD FEMA-CID 480895 COUNTY HAYS COUNTY-FIPS 48209 COMMUNITY CITY OF VILLAGE OF BEAR CREEK FEMA-CID 481679 COMMUNITY CITY OF BUDA FEMA-CID 481640 COMMUNITY CITY OF DRIPPING SPRINGS FEMA-CID 481667 COMMUNITY CITY OF HAYS FEMA-CID 481669 COMMUNITY CITY OF MOUNTAIN CITY FEMA-CID 481671 COUNTY LLANO COUNTY-FIPS 48299 COUNTY TRAVIS COUNTY-FIPS 48453 COMMUNITY CITY OF AUSTIN FEMA-CID 480624 COMMUNITY CITY OF BEE CAVE FEMA-CID 481610 COMMUNITY VILLAGE OF BRIARCLIFF FEMA-CID 481649 COMMUNITY CITY OF JONESTOWN FEMA-CID 481597 LAGO VISTA FEMA-CID 481588 COMMUNITY CITY OF LAKEWAY FEMA-CID 481303 COMMUNITY VILLAGE OF POINT VENTURE FEMA-CID 481691 COMMUNITY CITY OF ROLLINGWOOD FEMA-CID 481029 COMMUNITY VILLAGE OF SAN LEANNA FEMA-CID 481305 COMMUNITY CITY OF SUNSET VALLEY FEMA-CID 481127 COMMUNITY VILLAGE OF THE HILLS FEMA-CID 480063 COMMUNITY VILLAGE OF VOLENTE FEMA-CID 481696 COMMUNITY CITY OF WEST LAKE HILLS FEMA-CID 481030 COUNTY WILLIAMSON COUNTY-FIPS 48491 HYDROLOGIC UNIT 12090205 None Acknowledgement of FEMA would be appreciated in products derived from these data. These digital data are produced for the purposes of updating/creating a FIRM Database. Federal Emergency Management Agency mailing

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Washington District of Columbia 20472 USA 1-877-336-2627 miphelp@riskmapcds.com ArcGIS software was used to create a digital surface model for this watershed's project area. The LiDAR datasets were added to a mosaic dataset and prioritized using the data's age and accuracy. The mosaic dataset was exported to make a seamless bare earth 5-foot DEM for mapping and modeling according to the model area extents, including a 1,000 meter buffer. A 5-meter DEM was used during the stream centerlines creation. Stream centerlines were auto-generated using Python scripts and the 5-meter DEM for the 0.5-square-mile drainage area. The streams were manually edited using the 5-meter DEMs as a source for horizontal alignment and vertical elevation. These stream centerlines were created for use in the hydraulic analysis. The final streams were delivered with the BFE deliverable. DEM files are the source dataset. Accuracy reports were acquired and confirmed the accuracy of the DEMs was sufficient for use in this project. Checks were performed to ensure the data files can be opened, are georeferenced properly, and cover the geographic area completely. Additionally, field survey checkpoints are obtained to evaluate the accuracy of LiDAR products. As specified in the American Society for Photogrammetry and Remote Sensing (ASPRS) Positional Accuracy Standards for Digital Geospatial Data, checkpoints in vegetated and non-vegetated areas are tested in a project area. A statistical analysis between the difference in elevations of the field survey checkpoints and LiDAR-derived, bare earth elevations at the same locations provides a quality assessment of the LiDAR data. The bare earth surface data is an estimation of the bare earth surface and does not include vegetative and built features. Likewise, it contains estimates of water edges at the time of data collection, and may not reflect current conditions. The bare earth surface will contain voids where insufficient energy was reflected from the surface to generate a valid return from the terrain. Voids in the bare earth surface tend to occur in heavily vegetated areas, water bodies, and beneath buildings, motor vehicles, bridges etc. Fresh or wet asphalt, wet sand and certain types of vegetation can also cause voids or anomalous elevations. The data may have been further processed to remove points found to be within delineated water bodies. Low confidence areas are delineated and provided in a separate dataset. The LiDAR data horizontal accuracy is in compliance with the National Standard for Spatial Data Accuracy (NSSDA) RMSE estimation of elevation data in support of 2-ft contour mapping products as it is referenced in the FEMA Guidelines and Standards for Flood Risk Analysis and Mapping. The 1-meter DEM is comprised of the following data sets with their computed vertical accuracy of 3.4-03.9 cm RMSEz at the 95 percent confidence level. 0.034 Vertical accuracy assessment for the various sources was calculated according to ASPRS and NSSDA specifications. USGS 20200716 digital 20200716 Ground Conditions TOPO1 This USGS LiDAR project covers portions of Blanco, Burnet, Hays, Travis, and Williamson Counties, Texas within the Austin Travis-Lakes HUC8 study area. This USGS lidar project covers portions of 45 counties in the central to coastal regions of Texas. The acquisition was conducted from January 4, 2019, through February 20, 2019. Fugro served as the prime contractor for the project and was responsible for planning, acquiring, processing, and producing derivative products of high resolution lidar data (QL2) over the project area. The vertical accuracy (RMSEz, or root mean square error in the z direction) of this dataset is 3.8 centimeters (cm). The native cell size of the data is 1 square meter. STRATMAP 20210409 digital 20180420 Ground Conditions TOPO2 This STRATMAP LiDAR project covers Burnet County, Texas within the Austin Travis-Lakes HUC8 study area. This StratMap lidar project covers portions of 21 counties in northern and central Texas. This project was managed by the Texas Strategic Mapping (StratMap) Program and utilized the StratMap contracts held by the Texas Department of Information Resources (DIR). Collection took place January 7, 2020, through April 24, 2020 with re-flights in June and August 2020. Data was collected and processed by the Sanborn Mapping Company, LLC with third party quality assurance/quality control performed by AECOM. Eisenhower State Park was collected at a higher point density of 8 points per square meter. The vertical accuracy (RMSEz) of this dataset is 3.9 cm. The native cell size of the data is 1 m2. Using NSSDA methodology, the horizontal accuracy at the 95 percent confidence level was reported as 22.4 cm (target was 100 cm). USGS 20171214 digital 20171214 Ground Conditions TOPO3 This USGS LiDAR project covers Blanco, Burnet, and Llano Counties, Texas within the Austin Travis-Lakes HUC8 study area. This project was managed by the Texas Strategic Mapping (StratMap) Program and utilized the StratMap Contracts held by the Department of Information Resources (DIR). Collection took place January 28,2017, through March 22,2017. Data was collected and processed by Fugro EarthData, Inc. with third party quality assurance/quality control performed by AECOM. The vertical accuracy (RMSEz) of this dataset is 3.4 cm. The native cell size of the data is 1 m2. Terrain data used for flood risk analysis go through LiDAR preliminary processing and the unclassified point cloud data are tested as specified in the USGS National Geospatial Program Base LiDAR Specification Version 1.0. Where the Mapping Activity Statement (MAS) requires bare earth post-processing of the floodplain area of interest (AOI), the elevation data are tested and comply with both the Fundamental Vertical Accuracy (FVA) and Consolidated Vertical Accuracy (CVA) requirements. Where no bare earth post-processing is specified, only the FVA requirements apply for LiDAR preliminary processing. The processing of this leveraged data was performed in State Plane Lambert Conformal Conic, Texas North Central Zone (projection), 4202 (projection zone). The FEMA spatial files required are submitted in the Geographic Coordinate System (GCS). Using NSSDA methodology, the horizontal accuracy at the 95 percent confidence level was reported as 47.7 cm (target was 100 cm). 20220805 7.8441500000000005e-008 7.8441500000000005e-008 Decimal degrees North American Datum of 1983 Geodetic Reference System 80 6378137.0 298.257222101 North American Vertical Datum of 1988 0.0001 feet Attribute values S_Submittal_Info A spatial data set consisting of polygons depicting the extents of the studied area. FEMA FIRM Database Technical Reference (available at http://www.fema.gov/guidelines-and-standards-flood-risk-analysis-and-mapping and on the FEMA Risk MAP Knowledge Sharing Site). Bare Earth DEM An elevation model where bare-earth elevation values have regularly spaced intervals in latitude and longitude (x and y). FEMA Guidelines and Standards for Flood Risk Analysis and Mapping (available at http://www.fema.gov/guidelines-and-standards-flood-risk-analysis-and-mapping and on the FEMA Risk MAP Knowledge Sharing Site) The Terrain data package is made up of several data themes containing primarily spatial information. These data supplement the elevation datasets by providing additional information to aid flood risk evaluation and flood hazard area delineations. FEMAs Guidelines and Standards for Flood Risk Analysis and Mapping contains a detailed description of the data themes and references to other relevant information. FEMA, Mapping Information Platform mailing

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Washington District of Columbia 20472 USA 1-877-336-2627 miphelp@riskmapcds.com No warranty expressed or implied is made by FEMA regarding the utility of the data on any other system nor shall the act of distribution constitute any such warranty. FEMA-Terrain-Capture http://hazards.fema.gov Contact Distributor 20220805 MIPHelp Federal Emergency Management Agency mailing

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Washington District of Columbia 20472 USA 1-877-336-2627 miphelp@riskmapcds.com FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 http://hazards.fema.gov http://www.epsg.org FEMA NFIP Metadata Content and Format Standard