This is a 2D Hydraulic model (HEC-RAS) for the Upper San Saba River between Fort McKavett and Menard, TX. Model geometry is based on USGS 3DEP data (2018), with underwater bathymetry “burned” in using cross-sections sampled in the field in 2018. The model was calibrated based on water surface and velocities measured during data collection. ... : The following is a summary of available data utilized for developing a bathymetric terrain for 2D hydraulic modeling using HEC-RAS. Data available for model calibration and validation is also discussed. Available Data Cross-section data was collected at approximately 350-foot increments with the following devices: Table 1. Equipment used and their accuracy for field data collection. Parameter Equipment Unit Accuracy Location GPSMap 64 Handheld GPS 10-50 feet Velocity Hach Velocity Meter (Model FH950.1) 0.1 feet/second Depth An adjustable “ruler” stick with feet as units 0.1 feet Wetted Width Laser Technology Inc. TruPulse 360r 3 feet to nonideal (natural) target The data was collected from July 10 to 26, 2018. The USGS Gage on the San Saba River at Menard, TX (08144500) shows discharges varied from 8 to 18 cfs during the time period. USGS 3DEP data was used in the HEC-RAS terrain. These data were collected at a 1-meter resolution over a period of two months (February 14 to April 22, 2018) over a range of ...