Lower Ouachita - Bayou De Loutre (OL) Louisiana Watershed Initiative (LWI) Models and Data

This package consolidates the HUC08040202 Lower Ouachita - Bayou De Loutre (OL) Louisiana Watershed Initiative modeling program and related data that was developed by Freese and Nichols, Inc. (FNI).

For project planning and design, it is recomended to use the final LWI base models: "Lower Ouachita - Bayou De Loutre - Design Storm Atlas 14 Everywhere HEC-RAS Model for Louisiana Watershed Initiative" and "Lower Ouachita - Bayou De Loutre - Design Storm HEC-HMS Model for Louisiana Watershed Initiative." Within the HEC-RAS design storm model, final design storm plans are provided for the 35 design storm frequency (5-year, 10-year, 25-year, 50-year, 100-year, 200-year, 500-year) and duration combinations (6-hr, 12-hr, 24-hr, 48-hr, 72-hr). The critical duration is 24-hr, and the associated plans are recommended for design. Results rasters are provided for each of the 24 hr event. These rasters were created by running the 24-hr event in HEC-RAS and exporting the WSE, Depth and Velocity rasters. The depth rasters created from the design storm models were used in the provided Go-Consequences consequence analyses. The Go-Consequences analysis was verified using select events in the consequence analysis software HEC-FIA; these results are also provided.

Calibration and Validation models are provided in this package for reference.

The modeled streams include: Ouachita River, Bayou De Loutre, Bayou De Butte, Big Creek, Frank Lapere Creek, Rock Creek, Shiloh Creek, and Williamson Creek. The terrain used for modeling primarily sources the 2021 Department of Transportation and Development LiDAR with bathymetry incorporated from surveys conducted by Bryant Hammett & Associates in 2021 and 2022. The model and terrain use the vertical datum NAVD88 and the State-Plane projection NAD 1983 (2011) State Plane Louisiana North FIPS 1701 (US Feet).