The Army Corps of Engineers said today that it won’t take as long or cost as much as expected to study the proposed deepening of the Charleston Harbor.

Officials also said if everything goes just right, the shipping channel could be deepened by 2020, four years ahead of previous estimates. The State Ports Authority wants the channel dredged to a depth of at least 50 feet to accommodate larger container ships.

The channel has a federally authorized depth of 45 feet, and the Corps’ study is meant to determine what depth is feasible and in the nation’s best interest.

“A host of alternatives” will be studied, said Lt. Col. Edward Chamberlayne, commander of the Corps’ Charleston District office.

Chamberlayne said the study that began in June 2011 should cost about $15 million and take up to 4 more years to complete. The Corps previously estimated the entire study would cost $20 million and take as long as eight years, or as few as four years.

Chamberlayne said the Charleston study is now at the forefront of a national effort to speed up the review process for undertakings such as harbor deepening. He said the timeline for the entire project was shortened by finding ways to overlap different aspects of studying and engineering the deepening, by being scaling back some of the data collection in favor of “educated assumptions,” and by changing an estimate of construction time.

Dredging the shipping channel to a greater depth is a top priority of the State Ports Authority, because larger, heavier container ships are expected to call on Southeast U.S. ports following an expansion of the Panama Canal that could be completed in early 2015.

The Corps had been saying that the deepening project, dubbed Post-45, would likely not be completed before 2024. That timeline has been blasted by critics.

Years-long studies have been the norm for U.S. ports seeking deeper water. In Georgia, the Port of Savannah has been seeking federal approval for deepening the Savannah River since 1996, and a final report was just issued by the Corps this year.

Georgia’s project is the subject of multiple legal challenges filed in South Carolina.

The timeline for Charleston’s Post-45 project was not firmed up until Wednesday morning. Port officials applauded the reduction in the timeline, but said 2020 is still too long to wait.

“I think we can do more,” said SPA President and CEO Jim Newsome. “The harbor was (last) deepened in 2004, and not a lot has changed.”

The SPA says it already can accommodate some of the largest container ships that call on Southeast ports at high tide. Deepening the harbor would remove the tidal restriction.

Read more in Thursday’s editions of The Post and Courier and follow David Slade on Twitter @DSladeNews.