Charleston Harbor Post 45 Project

The Charleston Harbor is now the deepest port on the East Coast at 52 feet. On Dec. 5, 2022, the Charleston District gathered with stakeholders to celebrate the completion of the Charleston Harbor Post 45 Deepening Project. This project addressed 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 the port in the Lowcountry. 

The Charleston District has worked 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 was one of the first seven that President Obama's Administration expedited under its "We Can't Wait" initiative for critical infrastructure projects. 

Our non-federal partner, the SCPA, is one of the largest economic drivers in the state, providing over $60 billion in statewide economic impact. More than one in 10 jobs in the state are directly related to port activities. The port has set record numbers of imports nearly every month for the past two years and recently opened the new state-of-the-art Hugh K. Leatherman terminal in 2021.

Completing the deepening allows for the largest ships in the world to visit no matter their load, the tide, or the time of day. Before the project was entirely complete however, records for the largest ships to visit Charleston were already being broken when conditions allowed. First to break the record was the CMA-CGM Marco Polo in May 2021, followed by the COSCO Camellia in March 2022. In September of the same year, with a draft of 48 feet, 11 inches, the MSC Rayshmi visited Charleston Harbor, officially taking the title as the largest ship to ever visit.

The USACE team worked tirelessly to complete the project on time and budget, and it was the first large navigation project in the nation to be conducted under the Corps' streamlined civil works planning process. The team was comprised of engineers, navigation specialists, scientists, economists, planners, and project managers from across USACE representing the best and the brightest in their fields, and the deepening occurred over the course of seven district commanders starting with Lt. Col Jason Kirk and culminating with Lt. Col. Andrew Johannes.

Beginning in 2011, the $580 million Post 45 Harbor Deepening Project aimed to deepen Charleston Harbor from 45 feet to 52 feet. The additional depth allows for the world's largest fully loaded container ships to call on the port, no matter the tide. With the completion of this project, Charleston is now seeing record-breaking levels of cargo traveling through its port, and new businesses are taking advantage of the depth.

Post 45 is the first study to be completed in the Corps 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 collaborated closely 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 significance, allowing post-Panamax vessels to call upon the harbor.


Post 45 Documentation

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 Final Report and Environmental Impact Statement

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

 Post 45 Final Coastal Morphology Evaluations and Storm Surge Analysis

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.

 Supplemental Information Reports
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.


 Final Supplemental Environmental Assessment
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
 Environmental Monitoring Plans and Reports
 Additional Information
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



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.