Stantec Consulting Services 88880808 Version 2.5.3.6 FEMA-DCS-Terrain Austin, TX Texas Natural Resources Information System https://tnris.org/ Federal Emergency Management Agency Unknown Terrain data, as defined in FEMA's 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) 88880808 MIP Submission Date In work Unknown -99.62 -98.18 28.54 27.53 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 06 STATE TX COUNTY Dimmit COUNTY-FIPS 48127 COMMUNITY Dimmit County FEMA-CID 48127 HYDROLOGIC UNIT 12110105 None REGION 06 STATE TX COUNTY Duval COUNTY-FIPS 48131 COMMUNITY Duval County FEMA-CID 48131 HYDROLOGIC UNIT 12110105 None REGION 06 STATE TX COUNTY La Salle COUNTY-FIPS 48283 COMMUNITY La Salle County FEMA-CID 48283 HYDROLOGIC UNIT 12110105 None REGION 06 STATE TX COUNTY Live Oak COUNTY-FIPS 48297 COMMUNITY Live Oak County FEMA-CID 48297 HYDROLOGIC UNIT 12110105 None REGION 06 STATE TX COUNTY McMullen COUNTY-FIPS 48311 COMMUNITY McMullen County FEMA-CID 48311 HYDROLOGIC UNIT 12110105 None REGION 06 STATE TX COUNTY Webb COUNTY-FIPS 48479 COMMUNITY Webb County FEMA-CID 48479 HYDROLOGIC UNIT 12110105 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

500 C Street, S.W.

Washington District of Columbia 20472 USA 1-877-336-2627 miphelp@riskmapcds.com Original data development environment may vary. The classification and quality control (QC) of LiDAR data is carried out using TerraScan software v. 8.003 by Terrasolid Limited of Helinski, Finland. The tiling and final LAS file creation was performed using LiDAR CuePac v5.0 from GeoCue Corporation of Madison, Alabama, USA. Finishing of the data is done using Esri's ArcGIS software. The submitted geodatabase was created using ArcGIS version 10.0. Ground classification routines are used to remove any non-ground points and generate an accurate ground surface. The ground routine consists of three main parameters (building size, iteration angle, and iteration distance); by adjusting these parameters and running several iterations of this routine an initial ground surface is developed. The building size parameter sets a roaming window size. Each tile is loaded with neighboring points from adjacent tiles and the routine classifies the data section by section based on this roaming window size. The second most important parameter is the maximum terrain angle, which sets the highest allowed terrain angle within the model. Once the ground routine has been completed a manual quality control routine is done using hillshades, cross-sections, and profiles. After this QC step, a peer review and supervisor manual inspection is completed on a percentage of the classified tiles based on the project size and variability of the terrain. After the ground classification corrections are completed, the dataset is processed through a water classification routine that utilizes breaklines to automatically classify hydrographic features. The water classification routine selects ground points within the breakline polygons and automatically classifies them as class 9, water. During this water classification routine, points which are in close proximity (1 m) to the hydrographic features are moved to class 10, ignored ground. In addition to classes 1, 2, 8, 9, and 10, the project allows for a Class 7, noise points. This class is only used if needed when points can manually be identified as low/high points. The fully classified dataset is then processed through a comprehensive quality control program. The data are classified as follows: Class 1 = Unclassified. This class includes vegetation, buildings, noise etc. Class 2 = Ground Class 7 = Noise Class 8 = Model Key Points Class 9 = Water Class 10 = Ignored Ground Class 11 = Withheld The LAS header information was verified to contain the following: Class (Integer) GPS Week Time (0.0001 seconds) Easting (0.01 m) Northing (0.01 m) Elevation (0.01 m) Echo Number (Integer 1 to 4) Echo (Integer 1 to 4) Intensity (8 bit integer) Flight Line (Integer) Scan Angle (Integer degree) 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. A minimum of 100 checkpoints are tested in a project area. At least 20 for 5 different land vegetation categories (forest, built-up, scrub, weeds/crop, and bare-earth/low grass) are tested with forested areas requiring a minimum of 40 checkpoints. 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 2ft. contour mapping products as it is referenced in the FEMA Guidelines and Standards for Flood Risk Analysis and Mapping. NSSDA 0.125 Vertical accuracy assessment was computed at 0.125 meters according to ASPRS and NSSDA specifications. Texas Natural Resources Information System 1/1/2018 ONLINE 20180101 Publication Date TOPO1 S_Submittal_Info Texas Natural Resources Information System 1/1/2018 ONLINE 20180101 Publication Date TOPO2 S_Submittal_Info Texas Natural Resources Information System 1/1/2018 ONLINE 20180101 Publication Date TOPO3 S_Submittal_Info Texas Natural Resources Information System 1/1/2019 ONLINE 20190101 Publication Date TOPO4 S_Submittal_Info State Plane Coordinate System 1983 4204 28.3833333333 30.2833333333 -99.0000000000 27.8333333333 1968500.0000000000 13123333.3333333302 coordinate pair 0.0000000784 0.0000000784 Foot_US North American Datum of 1983 GRS_1980 6378137.0000000000 0.0033528107 North American Vertical Datum of 1988 0.0001000000 Foot_US Implicit coordinate 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) Tiling Index A spatial dataset that describes the tiling system used for multiple files of the same type. 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. FEMA's 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

500 C Street, S.W.

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-DCS-Terrain http://hazards.fema.gov Contact Distributor 20211101 Mason Liebau Stantec mailing

70 NE Interstate 410 Loop #1100

San Antonio Texas 78216 USA (210)714-9980 mason.liebau@stantec.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