LWI Region 3 Modeling Overview

Figure 1-1: LWI Region 3 spans four Hydrologic Unit Code (HUC) 8s and covers portions of Arkansas and northeastern Louisiana.

Major rivers in the Region include Boeuf River, Bayou Lafourche, Turkey Creek, and Big Rive (Boeuf River Watershed); Bayou Macon and Joes Bayou (Bayou Macon Watershed); Tensas River and Tensas Bayou (Tensas River Watershed); and Bayou Cocodrie in the Bayou Cocodrie Watershed. Besides the flat topography of the Region, the presence of levee and pump systems, dams, and diversion structures result in complex hydrologic and hydraulic conditions. WSP modeled this system using the following software and key inputs: { Hydrologic Engineering Center – Hydrologic Modeling System (HEC-HMS) (v10.1) for the hydrologic study of the Arkansas portion of Boeuf River and Bayou Macon Watersheds

{ Hydrologic Engineering Center – River Analysis System (HEC-RAS) (v6.3.1) for two-dimensional (2D) rain-on-mesh (ROM) studies of all four watersheds in Louisiana { Light detection and ranging (LiDAR ) terrain dataset provided by the U.S. Geological Survey (USGS) { High Water Marks (Ouachita Parish, March 2016 event), USGS, and U.S. Army Corps of Engineers (USACE) gage data for calibration of models and verification of model results { Survey collection of over 600 channel cross sections and 1,350 hydraulic structures with data incorporated into the models

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Region 3 Description