Charleston Harbor Post 45 Overview

The Charleston Harbor Post 45 Deepening Project looks to address transportation inefficiencies by deepening and widening Charleston Harbor to allow for growth in the shipping industry with the influx of Post-Panamax ships calling on port in the Lowcountry.  The project will provide over $169 M in average annual benefits.

The Charleston District has been working with the project’s non-federal sponsor, the South Carolina Ports Authority, since 2010 to complete studies and move the project toward a 52 foot deep federal channel. The project is one of the first seven that President Obama’s Administration expedited under its “We Can't Wait” initiative for critical infrastructure projects. 

Post 45 is currently in the Construction Phase of the U.S. Army Corps of Engineers’ Civil Works Process. During this phase, the Charleston District will focus on the solicitation, award, and construction management of dredging and upland placement site construction contracts to complete the implementation for the authorized modifications to the federal channel for Charleston Harbor. In September of 2017 the District awarded the first construction contract for deepening a portion of the entrance channel to Great Lakes Dredge and Dock Company (GLD&D), LLC, for approximately $47.  In October of 2017 the District awarded the second contract, to cover the remaining portion of the entrance channel deepening, to Great Lakes Dredge and Dock Company (GLD&D), LLC, with a current obligated value of $278 M.  The construction started in the Charleston Harbor Entrance Channel in March 2018 and the entire project will take 40-76 months depending on full-funding, dredge availability, weather, and a variety of other factors. While the Entrance Channel dredging is being initiated, the District is simultaneously finalizing the design of the remaining channel reaches in the Lower and Upper Harbor areas. Throughout the construction phase the District will continue to work with stakeholder agencies while implementing the mitigation and monitoring requirements of the project. The estimated cost-share for the construction portion of the project will be $345.4 million for the federal government and $203.5 million for the SCPA, making the total project cost approximately $548.9 million. 

Prior to the Construction Phase, the Charleston District completed the Reconnaissance Phase in 2010, which demonstrated that a large percentage of vessels calling on Charleston Harbor were tide-restricted, and the Feasibility Phase, which determined that deepening Charleston Harbor was both economically beneficial and environmentally acceptable to the nation. In 2015, the Final Integrated Feasibility Report and Environmental Impact Statement concluded that the recommended plan for the Charleston Harbor federal channel would be to deepen it to 52 feet, as well as widening areas for turning basins. In December 2015, the District and the SCPA executed the design agreement for the project to enter the Pre-construction Engineering and Design (PED) Phase. During this phase the District completed major remaining analyses and developed the first sets of plans and specifications for construction of the entrance channel deepening. After the Assistant Secretary for the Army for Civil Works signed the Record of Decision in January 2016, the project was passed to Congress for consideration for authorization. The project was authorized for construction in December 2016, with the passage of the Water Infrastructure Improvements for the Nation Act of 2016. The Project Partnership Agreement for the Construction Phase of the project was executed on July 19, 2017.

Post 45 is the first study to be completed in the Corps entirely under their new SMART Planning process, as part of the Corps' Planning Modernization effort. This enabled the Charleston District to complete the Feasibility Phase in four years for approximately $11 million after an original estimate of seven years and $20 million. The Charleston District worked in close collaboration with state and federal partner agencies to complete the required studies and associated environmental reviews and permits. This has led Post 45 to become a model for future Civil Works projects around the Corps.

The Corps has maintained Charleston Harbor for more than 140 years and has dredged it every year during that time to ensure the channel is at the required federal project depth, spending approximately $10-15 million and removing 2-3 million cubic yards of maintenance material from the harbor floor each year. Construction to deepen the harbor to the now federally authorized 45 foot depth began in 1999 and was completed in 2004. Charleston Harbor has strategic national importance for military readiness, supporting Joint Base Charleston, and regionally the harbor deepening is of economic importance, allowing Post-Panamax vessels to call upon the harbor.

Post 45 Documentation

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To access the Final Integrated Feasibility Report and Environmental Impact Statement, please click on the appropriate links:

Signed Record of Decision

Signed Chief's Report

Main Report, Executive Summary, and Abstract

Supplemental Materials:

Appendix A- Engineering Attachments

Appendix B- Geotechnical Attachments

SCDNR Benthic Survey of Charleston Harbor

USACE-ERDC - Wetland Classification Study

USFWS Coordination Act Report

Sediment Sampling Final Report

Geophysical Investigation, Hardbottom Resources and Cultural Resources (Phase 1)

Cultural Resource Investigation Phase 2

Public Comments

The U.S. Army Corps of Engineers, Charleston District, working in cooperation with the South Carolina Ports Authority and in accordance with the Final Integrated Feasibility Report and Environmental Impact Statement (IFR/EIS), has reviewed and approved the Final Coastal Morphology Evaluation and Final Storm Surge Analysis posted below.

These Supplemental Information Reports (SIRs) were prepared in accordance with Section 13(d) of Engineer Regulation (ER) 200-2-2, Procedures for Implementing the National Environmental Policy Act (NEPA) and the Council on Environmental Quality (CEQ) Regulations for Implementing the Procedural Provisions of the National Environmental Policy Act (40 Code of Federal Regulations (CFR) Pts. 1500-1508). These SIRs accompany the Charleston Harbor Post 45 Final Integrated Feasibility Report and Environmental Impact Statement (IFR/EIS) and the Supplemental Environmental Assessment (EA), which are incorporated by reference. The first SIR, finalized in March 2017, further described the entrance channel design modifications that developed during the Pre-construction Engineering and Design (PED) phase (Part 1) as well as the construction of a pile in the lower harbor to support wave and current monitoring for compliance with Section 106 of the National Historic Preservation Act (Part 2). The second SIR, finalized in June 2018, serves to document a minor design and location modification to the artificial reefs. The conditions, project description, and environmental effects described in the Final IFR/EIS and Supplemental EA are still valid, and these SIRs are designed to provide supplemental information to the public and agencies to keep them informed of minor project changes. Supplementation of the IFR/EIS is not required per 40 CFR 1502.9(c) because substantial changes to the proposed action have not occurred nor do the changes have significant bearing on the findings of the Final IFR/EIS.


The U.S. Army Corps of Engineers, Charleston District, working in cooperation with the South Carolina Ports Authority, has prepared a Final Supplemental Environmental Assessment (EA) to evaluate potential beneficial use of dredged material projects that could be completed as part of the deepening and widening of Charleston Harbor. In 2014, USACE prepared an Integrated Feasibility Report and Environmental Impact Statement to evaluate potential impacts associated with the navigation improvements of Charleston Harbor. A Record of Decision was signed on January 12, 2016.

The Final IFR/EIS identified several items for further evaluation during the PED phase, one of those being a commitment to evaluate additional beneficial use alternatives for the new work dredged material. This supplemental EA and Finding of No Significant Impact (FONSI) addresses the evaluation of beneficial uses of dredged material for the new work material dredged from the channel. It also discusses the process and results of fine-tuning the locations of artificial reefs (previously evaluated during the Feasibility Phase in the Final IFR/EIS) near the entrance channel and identifying any existing approved reefs that could be supplemented with rock material from the channel.

Our evaluation led to proposing potential projects to augment eroding islands in the Charleston Harbor (Crab Bank, Shutes Folly, and a portion of Morris Island) with dredged material from the federal navigation channel. Our findings are that the proposed beneficial use projects would have no significant environmental impacts.

In accordance with provisions of the National Environmental Policy Act (NEPA), a draft of this Supplemental EA was released for public and agency comments on October 31, 2016 for a 30 day commenting period. Responses to comments can be found within Appendix M.


Appendix A- SCDNR Sediment Characterization of Crab Bank and Shutes Folly

Appendix G- Subsurface Investigation and Geotechnical Lab Results

Appendix B- SCDNR Benthic Characterization of Crab Bank and Shutes Folly Appendix H- Side Scan Sonar Results for Additional Hardbottom Habitat Identification in Entrance Channel
Appendix C- Entrance Channel Hardbottom Surveys Appendix I- Alternatives Spreadsheet with Interagency Input
Appendix D- Hardbottom Habitat Identification in Support of Artificial Reef Sites Appendix J- 404b1 Guidelines
Appendix E- Cultural Resources Surveys in Support of Artificial Reef Sites Appendix K- Coastal Modeling in Support of Beneficial Use Determination
Appendix F- Lower Harbor Sediment Sampling in Support of Beneficial Use Analysis Appendix L- Habitat Equivalency Analysis Results
Appendix M-Public and Agency Comments and Responses
The Charleston Harbor Post 45 Project will deepen the harbor to 52 feet and complete widening in the associated channels and turning basins. The authorized plan will cost approximately $529 million.
Deepen the existing entrance channel from a project depth of 47 feet to 54 feet mean low level water and extend it approximately three miles seaward from the existing location to a depth contour of 54 feet.
Deepen the inner harbor from an existing project depth of 45 feet to 52 feet from the Entrance Channel to the confluence of the Wando and Cooper Rivers, about two miles up the Wando River to the Wando Welch container facility and about three miles up to the Cooper River to the New Navy Base Terminal, and to a project depth of 48 feet over the five mile reach leading from the New Navy Base Terminal to the North Charleston container facility.
- Enlarge the existing turning basins at the Wando Welch, New Navy Base and North Charleston terminals - Widen selected channel reaches

Post 45 Contact Info

Contact Info:

Charleston Harbor Post 45
69A Hagood Ave
Charleston, SC 29403

Post 45 Web Map

We have developed an interactive map showing the project features. To view the web map, click here.