Southwest Pass survey data is referenced to Louisiana South State Plane Coordinates North American Data 1983 with sounding reference below Mean Lower Low Water in U.S. Survey Feet unless otherwise noted on the plan sheet.

SPECIAL NOTICE: Bypass channel for the lower Mississippi River, mile 8-13 above Head of Passes, can be viewed on the pre-removal multibeam surveys using these links.

Sheet 1: Pre-Removal Survey

Sheet 2: Pre-Removal Survey

The Post-Removal Multibeam Surveys can be viewed at the links below:

Sheet 1: Post-Removal Survey

Sheet 2: Post-Removal Survey

South and Southwest Pass
   Survey title Survey date
       Index number    River mile PDF XYZ SHP
Southwest Pass (MLLW)
   Sheet 1 04/17/2024
       SW_01_SWP    MM 13.4-10.5 AHP PDF XYZ Shape
   Sheet 2 04/17/2024
       SW_02_SWP    MM 10.5-7.7 AHP PDF XYZ Shape
   Sheet 3 04/15/2024
       SW_03_SWP    MM 7.7-4.8 AHP PDF XYZ Shape
   Sheet 4 - Cubit's Gap 04/18/2024
       SW_04_SWP    MM 4.8-2.0 AHP PDF XYZ Shape
   Sheet 5 - Head of Passes 04/18/2024
       SW_05_SWP    MM 2.0-1.0 AHP PDF XYZ Shape
   Sheet 6 04/18/2024
       SW_06_SWP    MM 1.0-3.7 PDF XYZ Shape
   Sheet 7 04/18/2024
       SW_07_SWP    MM 3.7-6.7 PDF XYZ Shape
   Sheet 8 04/18/2024
       SW_08_SWP    MM 6.7-9.6 PDF XYZ Shape
   Sheet 9 04/18/2024
       SW_09_SWP    MM 9.6-12.4 PDF XYZ Shape
   Sheet 10 04/16/2024
       SW_10_SWP    MM 12.4-15.2 PDF XYZ Shape
   Sheet 11 04/16/2024
       SW_11_SWP    MM 15.2-18.0 PDF XYZ Shape
   Sheet 12 04/16/2024
       SW_12_SWP    MM 18.0-21.0 PDF XYZ Shape
   Sheet 13 03/12/2024
       SW_13_SWP    MM 19.2-22.0 PDF XYZ Shape
   Offshore Dredged Material Disposal Site 05/03/2023
       SW_00_ODS    Offshore PDF XYZ Shape
   Pilottown Anchorage Area 04/15/2024
       SW_00_PTA    MM 6.8-1.5 PDF XYZ Shape
South Pass (MLLW)
   Sheet 1 01/30/2024
       SP_01_SPS    MM 0.0-1.0 PDF XYZ Shape
   Sheet 2 01/30/2024
       SP_02_SPS    MM 1.0-3.5 PDF XYZ Shape
   Sheet 3 01/30/2024
       SP_03_SPS    MM 3.5-6.5 PDF XYZ Shape
   Sheet 4 01/30/2024
       SP_04_SPS    MM 6.5-9.2 PDF XYZ Shape
   Sheet 5 01/30/2024
       SP_05_SPS    MM 9.2-12.1 PDF XYZ Shape
   Sheet 6 01/31/2024
       SP_06_SPS    MM 12.1-Gulf PDF XYZ Shape