Using HEC-GeoRAS as a Design Tool for the San Antonio River Mission Reach Restoration Project

摘要

The Mission Reach Ecosystem Restoration and Recreation (MR-ERR) is one of the largest civil works projects within the USACE Fort Worth District, restoring an 8-mile stretch of the San Antonio River downstream of the SART outlet to a more natural river ecosystem by designing wildlife habitat in the form of vegetation, rock riffles, embayments and restored river remnants.HEC-GeoRAS is both a pre-processor to build HEC-RAS models from GIS data and a postprocessor to map the resulting floodplain. Typically the ultimate goal is just to map the floodplain; however, a process has been developed to use the capabilities of GeoRAS as a tool to aid in the iterative design of channel improvements. By utilizing HEC-GeoRAS, as modifications are made to the design DTM for various purposes, they can be quickly reflected in the HEC-RAS model, allowing more design iterations within the project schedule. The DTM is then contoured to produce the grading plan, providing a direct correlation between the plans and HEC-RAS model.This paper will focus on how the import and export capabilities of HEC-GeoRAS are being used as design tools on a project to restore habitat while maintaining hydraulic capacity of 8 miles of the San Antonio River. Additional methods for modifying or comparing hydraulic data using the Graphical Cross Section Editor in HEC-RAS will also be discussed.