Description: This dataset represents the subbasin drainage boundaries for the Salado Creek Watershed and part of the final Digital Flood Insurance Rate Map (DFIRM) project Technical Support and Data Notebook (TSDN) deliverables. These subbasins were intended to specifically support the hydrologic modeling tasks related to this DFIRM project.The subbasins used to support the DIFRM project were originally defined by HDR in a previous project that was completed in 2001. These subbasins were created to support and inform the project’s Salado Creek Hydrology model. The DFIRM project team modified those basins where appropriate using Bexar County 5-foot topography obtained from the City of San Antonio. Catchments at the headwaters of the tributaries were defined to be approximately 1 square mile; non-headwater catchments averaged 1.4 square miles. This data’s quality was largely based on the resolution of the underlying elevation datasets; the boundaries of this dataset may change based on high resolution data, more current data, utilization of different delineations processes and methods, and over intent of what the data is supporting.
Copyright Text: San Antonio River Authority, FEMA, and Atkins (project contractor; formerly PBS&J)
Description: This dataset represents the subbasin drainage boundaries for a portion of the Medina River Watershed and was developed to support hydrologic modeling tasks specific to tributaries in the Medina Watershed within Bexar County; these subbasins were part of the final Digital Flood Insurance Rate Map (DFIRM) project Technical Support and Data Notebook (TSDN) deliverables.The original subbasins were developed using Arc Hydro and based on several Digital Elevation Models (DEM) from 2003. Specific drainage points were placed along streams target for various levels of engineering studies, Arc Hydro was then used to develop the initial subbasins for areas within and influencing streams being studied in Bexar County. The resulting subbasins were reviewed and modified as needed by the project team to ensure that drainages were approx. 1.5 square miles in urban areas and 3 square miles in rural areas. For drainage areas predominately outside of Bexar County, subbasin boundaries were delineated by hand using USGS 1:24,000 scale topography. The final subbasins were created to support and inform the project’s Medina River Watershed tributaries Hydrology models. This data’s quality was largely based on the resolution of the underlying elevation datasets; the boundaries of this dataset may change based on high resolution data, more current data, utilization of different delineations processes and methods, and over intent of what the data is supporting.
Copyright Text: San Antonio River Authority, FEMA, and AECOM (project contractor)
Description: This dataset represents the subbasin drainage boundaries for the Leon Creek Watershed and part of the final Digital Flood Insurance Rate Map (DFIRM) project Technical Support and Data Notebook (TSDN) deliverables. These subbasins were intended to specifically support the hydrologic modeling tasks related to this DFIRM project.The original subbasins, developed using HEC-GeoHMS with an upper limit of 1 square mile. These subbasins were initially used to support and inform hydrologic modeling activities and were based on 5-foot contours derived from a 2003 Digital Elevation Model. These subbasins boundaries were further reviewed by the project contracting team against 2005 2-foot contours and aerial imagery. Hand delineations replaced the automated delineations where it was deemed appropriate. This data’s quality was largely based on the resolution of the underlying elevation datasets; the boundaries of this dataset may change based on high resolution data, more current data, utilization of different delineations processes and methods, and over intent of what the data is supporting.
Copyright Text: San Antonio River Authority, FEMA, and AECOM (project contractor)
Description: This dataset represents the subbasin drainage boundaries for the Upper San Antonio River Watershed and was part of the final Digital Flood Insurance Rate Map (DFIRM) project Technical Support and Data Notebook (TSDN) deliverables. These subbasins were intended to specifically support the hydrologic modeling tasks related to this DFIRM project.For the drainage area above the confluence of the San Antonio River and Salado Creek, the contracting team used delineations the originated form the LMMP study for the Upper San Antonio River. This area was further subdivided to and combined with other previous studies to meet a target drainage area of 1 square mile. For the drainage area below the confluence to the Bexar County line, the contracting team used 5-foot contours generated form a 2003 Digital Elevation Model (DEM) for delineating subbasins. Subbasins were hand-delineated based on visual inspection of the topographic data and drainage patterns. The final subbasins were created to support and inform the project’s Upper San Antonio River Hydrology model. This data’s quality was largely based on the resolution of the underlying elevation datasets; the boundaries of this dataset may change based on high resolution data, more current data, utilization of different delineations processes and methods, and over intent of what the data is supporting.
Copyright Text: San Antonio River Authority, FEMA, and Pape-Dawson Engineers, Inc. (project contractor)