Client: Army Corps of Engineers
Completion Date: N/A
GEC is working with the Army Corps of Engineers and Gravity Drainage District 1 in Alexandria, Louisiana to determine alternatives to alleviate flooding in the City of Alexandria. The HEC-HMS (Hydrologic Management System) program was used to develop a hydrologic model based on NRCS GIS soils data, the National Land Cover Dataset, LIDAR data, quandrangles and DOQQ. Flow hydrographs from the HEC-HMS model were incorporated into the HEC-RAS (River Analysis System) Unsteady Flow model through HEC-DSS (Data Storage System) to model the Existing Conditions and various flood reduction alternatives. The existing conditions model was calibrated to a historical event using available stage gages. The HEC-GeoRAS extension to ArcView 3.2 was used with a LIDAR generated TIN to develop floodplains from the HEC-RAC water surface profiles.
