Choctaw Point Mitigation Plan

Mobile, Alabama

Alabama State Port Authority

In an effort to remain competitive in the world market, the Alabama State Port Authority (ASPA) prepared a 20-Year Master Plan focused on developing existing ASPA property to increase its containerized trade.  The ASPA planned to fill existing coastal wetlands to accommodate Choctaw Point Terminal construction projects.  These wetland areas were valuable fishery assets and therefore need to be mitigated.  Mitigation occurred by constructing new coastal wetland areas from existing upland areas at South McDuffie Island, North Garrows Bend, and the Arlington Cove sites.  The Mitigation Plan in the Choctaw Point Terminal Project Environmental Impact Statement (EIS) required that ASPA “…conduct a comprehensive study of tidal creeks and conduct hydrodynamic modeling of tidal creeks, if required.”  The goal of the study and modeling was to verify that the designed tidal creeks will provide adequate tidal exchange to support fringe marsh habitat, comparable to reference tidal creeks.  The study was to address issues such as:

  • Adequacy of tidal flushing in the proposed tidal creeks to establish and support emergent wetland vegetation and maintain adequate habitat within the tidal creeks for macroinvertebrates, crustaceans, fish, etc.
  • Comparison of proposed tidal creeks to reference tidal creeks in the immediate area.
  • Technical and construction criteria to accommodate tidal exchange and stormwater runoff.

McFadden Engineering evaluated the adequacy of tidal flushing in the proposed tidal creeks to establish and support emergent wetland vegetation and maintain adequate habitat within the tidal creeks for macroinvertebrates, crustatceans, fish, etc.  McFadden also compared proposed tidal creeks to reference tidal creeks in the immediate area and developed a tidal model to support horizontal and vertical control of wetlands plants.  In addition, McFadden completed technical and construction criteria to accommodate tidal exchange and

storm water runoff and completed conceptual design of the tidal creeks.