USACE: Mobile Harbor GRR Available

The U.S. Army Corps of Engineers’ Mobile District has announced the availability of the Draft Mobile Harbor, Mobile, Alabama Integrated General Reevaluation Report with Supplemental Environmental Impact Statement (Draft GRR/SEIS).

Image source: USACE

This document is being circulated to federal, state and local agencies and interested public for a 45-day comment period, said USACE in its latest release.

In June 2014, the Alabama State Port Authority requested the USACE consider increasing the depth and width of the Federal Mobile Harbor Channel, specifically asking the USACE to investigate the feasibility of constructing the channel to dimensions authorized in Section 201 of the 1986 Water Resources Development Act (WRDA).

The Tentatively Selected Plan (TSP) identified in the Draft GRR/SEIS recommends improvements that are less than the dimensions authorized in 1986 WRDA.

The Tentatively Selected Plan includes:

  • Deepening the existing Bar and Bay Channels (including the Choctaw Pass Turning Basin), and a portion of the River Channel by 5 feet (ft) to project depths of 52, 50, and 50ft, respectively; with an additional 2ft for advanced maintenance plus 2ft of allowable overdepth for dredging;
  • Incorporating minor bend easings at the double bends in the Bar Channel approach to the Bay Channel;
  • Widening the Bay Channel from 400ft to 500ft from the mouth of Mobile Bay northward for 3 nautical miles to provide a two-way traffic area for passing;
  • Expanding the Choctaw Pass Turning Basin 250ft to the south (at a depth of 50ft) to better accommodate safe turning of the design vessel and other large vessels.

According to USACE, material dredged during improvements will be placed at a relic shell mined area and the Mobile Ocean Dredged Material Disposal Site.

Any suitable Bar Channel new work material dredged in sufficient quantity to warrant placement at the Sand Island Beneficial Use Area (SIBUA) will be accomplished accordingly.

Future material from channel maintenance will be placed at those previously noted disposal sites in addition to open-water sites adjacent to the channel, the northwestern SIBUA expansion, and/or upland disposal sites.

Image source: USACE