Development of HEC-HMS and HEC-RAS models for urban floodplain mapping and flood damage reduction in Brownsville, Texas

The primary objective of this project was to develop hydrologic and hydraulic models for the floodplain analysis for Brownsville, Texas and analyze mitigation alternatives within a Geographic Information Systems (GIS) and digital data framework. This framework allowed for flexible manipulation of data and easy interpretation of the results. A methodology was developed that would make improvements to the more standard floodplain analysis approach with respect to both cost-effectiveness and accuracy. The project relied extensively on readily available digital data with a minimum, but sufficient, incorporation of field data for model verification purposes. Examples of this type of data included a LIDAR digital elevation model, global positioning system data, aerial photographs, and land use and land cover data. Another project objective included the collection and organization of various hydrologic and hydraulic data sources within an ArcView GIS system. The consolidation of this data will allow for rapid and efficient model updates as required in the future, and for the analysis of various alternatives for future flood control.