US Army Corps of Engineers
Charleston District Website

Historic number of dredges ready Charleston for future, larger ships

U.S. Army Corps of Engineers, Charleston District
Published July 6, 2021
Updated: July 6, 2021
Ship enters harbor

The CMA CGM Marco Polo pulls into Charleston Harbor.

Ship enters harbor

The CMA CGM Marco Polo pulls into Charleston Harbor.

Ship enters harbor

The CMA CGM Marco Polo pulls into Charleston Harbor.

Ship enters harbor

The CMA CGM Marco Polo pulls into Charleston Harbor.

The news is out: Charleston, S.C. is on track to have the deepest port on the east coast and harbor some of the world’s largest ships.

Large container ships, even super-post-Panamax vessels like the 1300-foot-long CMA CGM Marco Polo which cruised into Charleston’s harbor this May during high tide, will soon have safe passage here at any tide, fully-loaded.

These improvements in navigation are due to more than a century of continuous deepening and maintenance dredging led by the U.S. Army Corps of Engineers, Charleston District and the South Carolina Ports Authority’s strategic vision, as well as the District’s most recent deepening project, Post 45.

When the Corps initially began dredging Charleston Harbor in the mid-nineteenth century, principal entry channels were as shallow as 12 feet deep at low tide, forcing approaching ships into treacherous entry procedures and, over time, closing the harbor off from larger, more modern vessels and an ever-globalizing trade network.

At the time, the District’s deepening work was believed so vital to the regional economy that in 1878 the News & Courier — now Post and Courier — wrote, “[The] commercial effect will undoubtedly be great. There will no longer be any doubt … Charleston will soon become the receiving and distributing point for a vast section of the country now supplied by longer lines and at greater cost by Baltimore and New York. The field is open to Charleston.”

Today, in addition to maintenance dredging, Charleston District is deepening the harbor from 45 feet — a federally-authorized depth it achieved in its most recent deepening project which completed in 2004 — to 52 feet. The work is anything but simple. Stretching across roughly 40 miles of open ocean and inner channels, the dredging is broken up into five separate contracts and has required a historic number of dredges to work around-the-clock to complete the deepening work by the end of next year.

At one point in the project’s five-year timeline, nine dredges worked simultaneously, excavating and pumping millions of cubic yards of silt and sand from the ocean floor, across various points in the harbor, the most ever seen at one time in Charleston District’s 150-year history.

The project is currently scheduled to complete the extensive deepening work by Winter 2022. Once complete, the project will remove 40 million cubic yards of sediment — the equivalent of 12,230 Olympic pools — from Charleston Harbor’s federal channel.

A partnership with the S.C. Ports Authority, the $600 million project will improve navigation, open the port to a fleet of fully loaded modern vessels, facilitate trade and ultimately reduce the costs of consumer goods. For every dollar invested, the project is projected to return more than $6 to the economy.