Flood-Inundation Maps for the Amite and Comite Rivers From State Highway 64 To U.S. Highway 190 at Central, Louisiana

Scientific Investigations Report 2019-5028
Prepared in cooperation with the City of Central, Louisiana
By:

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Abstract

Flood-inundation maps for a 14.5-mile reach of the Amite River and a 20.2-mile reach of the Comite River from State Highway 64 to U.S. Highway 190 were created by the U.S. Geological Survey (USGS) in cooperation with the City of Central, Louisiana. These maps, which can be accessed through an interactive mapper at the USGS Flood Inundation Mapping Program website and from a companion USGS data release, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgages Amite River at Magnolia, La., (07377300) and Comite River near Comite, La. (07378000).

Flood profiles were computed for the Amite and Comite River reaches by using the two-dimensional (2D), finite-volume numerical modeling options in the U.S. Army Corps of Engineers Hydrologic Engineering Center’s River Analysis System (USACE HEC-RAS) software version 5.0.3. Models were calibrated to the current (2018) stage-discharge relations at the Amite River at Magnolia, La., and Comite River near Comite, La., streamgages, water-surface profiles from the March and August 2016 floods, and documented high-water marks from the flood of August 2016.

The hydraulic models were used to compute 37 individual water-surface profiles (21 for the Amite River and 16 for the Comite River) at 1.0-foot intervals ranging from the National Weather Service flood stage to the highest peak on record at the two streamgages. The 37 simulated water-surface profiles were used with a light detection and ranging-derived digital elevation model to delineate the flood extent and associated depth at each water level. The delineated areas (inundation maps) were merged into 127 combinations or possible flooding scenarios based on annual peak stage information from the two streamgaging stations.

The availability of these maps, along with real-time data delivered via the internet, will provide emergency management personnel and residents with information that is critical for flood-response activities such as evacuations and road closures, as well as for recovery efforts after floods.

Suggested Citation

Storm, J.B., 2019, Flood-inundation maps for the Amite and Comite Rivers from State Highway 64 to U.S. Highway 190 at Central, Louisiana: U.S. Geological Survey Scientific Investigations Report 2019–5028, 20 p., https://doi.org/10.3133/sir20195028.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Hydraulic Model Development and Flood-Inundation Map Library Creation
  • Summary
  • References Cited

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Flood-inundation maps for the Amite and Comite Rivers from State Highway 64 to U.S. Highway 190 at Central, Louisiana
Series title Scientific Investigations Report
Series number 2019-5028
DOI 10.3133/sir20195028
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Lower Mississippi-Gulf Water Science Center
Description Report: viii, 20 p.; Data Release; Flood Inundation Mapper
Country United States
State Louisiana
Online Only (Y/N) Y