Civil Systems Engineering, Inc.

Development of a digital flood insurance map (DFIRM) for the entirety of Hidalgo County based on new LiDAR topographic data. The scope involved base map DFIRM database development, LiDAR topographic data processing, detailed hydrologic and hydraulic modeling analyses, and digital floodplain database and mapping across more than 1,850 square miles.

Formulation and design of a flood control plan to divert floodwater from the North Main Drain to Raymondville Drain to reduce existing flooding problems within urbanized areas. The project involved extensive LiDAR data processing, ArcGIS mapping, and GeoHMS/HEC-HMS and GeoRAS/HEC-RAS hydrologic and hydraulic modeling for over 800 square miles of watershed and more than 100 miles of manmade drainage channels.

Preparation of a master drainage plan alongside a Capital Improvement Plan (CIP) for the City of Harlingen. Tasks included field surveys, LiDAR processing, GIS base mapping, drainage basin delineations, HEC-HMS modeling analysis, HEC-RAS modeling analysis for 49 drainage systems, and EPA-SWMM modeling analysis for 128 storm sewer systems, along with cost estimates for channel crossings, storm sewer improvements, and detention basins.

Development of a cost-effective master drainage plan to assist with outfall and storm sewer system improvements. The work scope encompassed field surveys, LiDAR processing, GIS mapping, drainage basin delineations, HEC-HMS modeling, HEC-RAS modeling for 49 drainage systems, and EPA-SWMM modeling for storm sewer systems.