That means dredging the Savannah River six feet to a depth of 48 feet wouldn't be finished until roughly two years after giant cargo ships are expected to begin using an expanded Panama Canal in 2014.
Georgia ports officials have warned that if the Savannah project lags too far behind the Panama Canal project, the larger container ships could shift to competing U.S. ports.
Curtis Foltz, the executive director of the Georgia Ports Authority, has been saying since September that he hoped the Savannah project would be finished before the end of 2015. He said Wednesday the Corps' anticipated end date isn't too troubling as long as work gets under way by the time the Panama expansion is complete.
"Anything after the end of 2014 and the beginning of 2015 is concerning to us," Foltz said.
"But the most important thing for our customers in commerce is that they know there is an end date and that end date is in sight."
The Army Corps, which issued a draft report on the Savannah harbor deepening last month, expects to get final authorization a year from now, said Col. Jeff Hall, the commander of the Corps' Savannah district.
Dredging the Savannah harbor is a massive undertaking. The shipping channel covers more than 35 miles of the Savannah River between the port and the Atlantic Ocean.
"Various pieces of it will be open prior to that time," Hall said. "But when you look at all the things we've got to do to ensure the successful deepening of the harbor, it's in that time frame of the end of fiscal 2016."
The federal government's fiscal year ends each Sept. 30.
Hall spoke to reporters Wednesday as the Army Corps held a workshop to gather public opinion on the project, which would use environmental mitigation to offset losses of freshwater marsh and reduced oxygen in a river teeming with wildlife.
Hall said the Army Corps plans to extend the comment period, scheduled to end Jan. 10, to give the public more time to digest his agency's weighty reports that are larger than three phonebooks.
Chris DeScherer, an attorney for the Southern Environmental Law Center, said environmentalists are scrambling to read and decipher the highly technical volumes in order to make a thorough critique.
Gov.-elect Nathan Deal, speaking to business leaders in Gwinnett County, called the Savannah deepening "a top priority."
The federal government is expected to foot the bill for about two-thirds of the $588 million project, which would also require a hefty infusion of state tax dollars.