Report on Charleston Harbor deepening expected today

File/AP Longer, heavier container ships are forcing some U.S. ports to deepen their harbors.

The Army Corps of Engineers is expected to announce Monday it is has completed a report crucial to lobbying Congress for money to deepen Charleston Harbor to 52 feet, giving the local port the deepest commercial waterway in the Southeast as it vies for larger ships.

The document, called the “chief’s report,” recommends the federal government and the State Ports Authority share in the cost of the $493.3 million project.

The harbor deepening is seen as a crucial step in keeping the Port of Charleston competitive with East Coast rivals trying to lure the same cargo to their facilities once an expansion of the Panama Canal is completed in 2016. It is part of more than $1 billion in capital projects the SPA wants to complete in the coming years.

A SPA spokeswoman would not confirm whether the chief’s report will be released Monday. The Army Corps has filed a draft version of the document on its website and key officials with the federal permitting agency are scheduled to discuss the project during Monday’s opening day of the S.C. International Trade Conference at Wild Dunes Resort on the Isle of Palms.

According to the draft report, the SPA and the federal government would split the cost of deepening the harbor to 50 feet, with the SPA picking up the cost for dredging the extra two feet. All told, the federal government would spend $224.3 million while the SPA’s share would be $269 million.

The state General Assembly already has set aside $180 million for the project, allowing the SPA to begin work almost immediately and before federal dollars are appropriated. The first phase of the deepening would include pre-construction engineering and design. The project is scheduled for completion by 2020, about the same time a new container terminal is to be built at the former Navy base in North Charleston.

The deepening will let heavy ships carrying up to 13,000 cargo boxes, called post-Panamax vessels, traverse the harbor at any time, regardless of the tide. Those ships will be making frequent visits to the East Coast once the Panama Canal expansion is completed next spring. Currently, the biggest ship that can make its way through Charleston Harbor carries about 9,500 cargo boxes.

“A competitive, growing port brings tremendous economic benefits to our state and our region,” Bill Stern, chairman of the SPA’s board, said earlier this year. “South Carolina, the Southeastern region and our nation will enjoy the positive impacts of the Charleston Harbor deepening for years to come.”

The Port of Charleston is among the nation’s top 10 ports for cargo container volume and its annual growth is more than double the national average.

In the draft report, Army Corps chief of engineers Thomas Bostick said the deepening “has positive net benefits and is economically justified.”

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Also, Bostick said: “Washington-level review indicates that the plan recommended by the reporting officers is technically sound, environmentally and socially acceptable and, on the basis of congressional directives, economically justified.”

In addition to paying its share of the deepening costs, the SPA will spend $5 million toward the protection of the Cooper River corridor in an effort to help mitigate any environmental effects the project might have.

In addition to deepening the harbor, the project would enlarge turn basins at the Wando Welch and Navy base container terminals to 1,800 feet diameter and enlarge the turn basis at the North Charleston terminal to 1,650 feet diameter to accommodate larger ships, according to the draft report.

The project also would require maintenance dredging of about 831,000 cubic yards each year, the draft report states.

Efforts to deepen Charleston Harbor began in 2011. The Legislature set aside money for construction costs two years later. The project also was named one of President Obama’s “We Can’t Wait” initiatives in 2013.

Reach David Wren at 937-5550 or on Twitter at @David_Wren_